#------------------------------------------------------------------------------
# File:         Exif.pm
#
# Description:  Read EXIF/TIFF meta information
#
# Revisions:    11/25/2003 - P. Harvey Created
#               02/06/2004 - P. Harvey Moved processing functions from ExifTool
#               03/19/2004 - P. Harvey Check PreviewImage for validity
#               11/11/2004 - P. Harvey Split off maker notes into MakerNotes.pm
#               12/13/2004 - P. Harvey Added AUTOLOAD to load write routines
#
# References:   0) http://www.exif.org/Exif2-2.PDF
#               1) http://partners.adobe.com/asn/developer/pdfs/tn/TIFF6.pdf
#               2) http://www.adobe.com/products/dng/pdfs/dng_spec_1_3_0_0.pdf
#               3) http://www.awaresystems.be/imaging/tiff/tifftags.html
#               4) http://www.remotesensing.org/libtiff/TIFFTechNote2.html
#               5) http://www.exif.org/dcf.PDF
#               6) http://park2.wakwak.com/~tsuruzoh/Computer/Digicams/exif-e.html
#               7) http://www.fine-view.com/jp/lab/doc/ps6ffspecsv2.pdf
#               8) http://www.ozhiker.com/electronics/pjmt/jpeg_info/meta.html
#               9) http://hul.harvard.edu/jhove/tiff-tags.html
#              10) http://partners.adobe.com/public/developer/en/tiff/TIFFPM6.pdf
#              11) Robert Mucke private communication
#              12) http://www.broomscloset.com/closet/photo/exif/TAG2000-22_DIS12234-2.PDF
#              13) http://www.microsoft.com/whdc/xps/wmphoto.mspx
#              14) http://www.asmail.be/msg0054681802.html
#              15) http://crousseau.free.fr/imgfmt_raw.htm
#              16) http://www.cybercom.net/~dcoffin/dcraw/
#              17) http://www.digitalpreservation.gov/formats/content/tiff_tags.shtml
#              18) http://www.asmail.be/msg0055568584.html
#              19) http://libpsd.graphest.com/files/Photoshop%20File%20Formats.pdf
#              20) http://tiki-lounge.com/~raf/tiff/fields.html
#              21) http://community.roxen.com/developers/idocs/rfc/rfc3949.html
#              22) http://tools.ietf.org/html/draft-ietf-fax-tiff-fx-extension1-01
#              23) MetaMorph Stack (STK) Image File Format:
#                  --> ftp://ftp.meta.moleculardevices.com/support/stack/STK.doc
#              24) http://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf (Exif 2.3)
#              25) Vesa Kivisto private communication (7D)
#              26) Jeremy Brown private communication
#              27) Gregg Lee private communication
#              28) http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/cinemadng/pdfs/CinemaDNG_Format_Specification_v1_1.pdf
#              29) http://www.libtiff.org
#              30) http://geotiff.maptools.org/spec/geotiffhome.html
#              IB) Iliah Borg private communication (LibRaw)
#              JD) Jens Duttke private communication
#------------------------------------------------------------------------------

package Image::ExifTool::Exif;

use strict;
use vars qw($VERSION $AUTOLOAD @formatSize @formatName %formatNumber %intFormat
            %lightSource %flash %compression %photometricInterpretation %orientation
            %subfileType);
use Image::ExifTool qw(:DataAccess :Utils);
use Image::ExifTool::MakerNotes;

$VERSION = '4.02';

sub ProcessExif($$$);
sub WriteExif($$$);
sub CheckExif($$$);
sub RebuildMakerNotes($$$);
sub EncodeExifText($$);
sub ValidateIFD($;$);
sub ProcessTiffIFD($$$);
sub PrintParameter($$$);
sub GetOffList($$$$$);
sub PrintLensInfo($);
sub ConvertLensInfo($);

# size limit for loading binary data block into memory
sub BINARY_DATA_LIMIT { return 10 * 1024 * 1024; }

# byte sizes for the various EXIF format types below
@formatSize = (undef,1,1,2,4,8,1,1,2,4,8,4,8,4,2,8,8,8,8);

@formatName = (
     undef,    'int8u',      'string',     'int16u',
    'int32u',  'rational64u','int8s',      'undef',
    'int16s',  'int32s',     'rational64s','float',
    'double',  'ifd',        'unicode',    'complex',
    'int64u',  'int64s',     'ifd64', # (new BigTIFF formats)
);

# hash to look up EXIF format numbers by name
# (format types are all lower case)
%formatNumber = (
    'int8u'       => 1,  # BYTE
    'string'      => 2,  # ASCII
    'int16u'      => 3,  # SHORT
    'int32u'      => 4,  # LONG
    'rational64u' => 5,  # RATIONAL
    'int8s'       => 6,  # SBYTE
    'undef'       => 7,  # UNDEFINED
    'binary'      => 7,  # (same as undef)
    'int16s'      => 8,  # SSHORT
    'int32s'      => 9,  # SLONG
    'rational64s' => 10, # SRATIONAL
    'float'       => 11, # FLOAT
    'double'      => 12, # DOUBLE
    'ifd'         => 13, # IFD (with int32u format)
    'unicode'     => 14, # UNICODE [see Note below]
    'complex'     => 15, # COMPLEX [see Note below]
    'int64u'      => 16, # LONG8 [BigTIFF]
    'int64s'      => 17, # SLONG8 [BigTIFF]
    'ifd64'       => 18, # IFD8 (with int64u format) [BigTIFF]
    # Note: unicode and complex types are not yet properly supported by ExifTool.
    # These are types which have been observed in the Adobe DNG SDK code, but
    # aren't fully supported there either.  We know the sizes, but that's about it.
    # We don't know if the unicode is null terminated, or the format for complex
    # (although I suspect it would be two 4-byte floats, real and imaginary).
);

# lookup for integer format strings
%intFormat = (
    'int8u'  => 1,
    'int16u' => 3,
    'int32u' => 4,
    'int8s'  => 6,
    'int16s' => 8,
    'int32s' => 9,
    'ifd'    => 13,
    'int64u' => 16,
    'int64s' => 17,
    'ifd64'  => 18,
);

# EXIF LightSource PrintConv values
%lightSource = (
    0 => 'Unknown',
    1 => 'Daylight',
    2 => 'Fluorescent',
    3 => 'Tungsten (Incandescent)',
    4 => 'Flash',
    9 => 'Fine Weather',
    10 => 'Cloudy',
    11 => 'Shade',
    12 => 'Daylight Fluorescent',   # (D 5700 - 7100K)
    13 => 'Day White Fluorescent',  # (N 4600 - 5500K)
    14 => 'Cool White Fluorescent', # (W 3800 - 4500K)
    15 => 'White Fluorescent',      # (WW 3250 - 3800K)
    16 => 'Warm White Fluorescent', # (L 2600 - 3250K)
    17 => 'Standard Light A',
    18 => 'Standard Light B',
    19 => 'Standard Light C',
    20 => 'D55',
    21 => 'D65',
    22 => 'D75',
    23 => 'D50',
    24 => 'ISO Studio Tungsten',
    255 => 'Other',
);

# EXIF Flash values
%flash = (
    OTHER => sub {
        # translate "Off" and "On" when writing
        my ($val, $inv) = @_;
        return undef unless $inv and $val =~ /^(off|on)$/i;
        return lc $val eq 'off' ? 0x00 : 0x01;
    },
    0x00 => 'No Flash',
    0x01 => 'Fired',
    0x05 => 'Fired, Return not detected',
    0x07 => 'Fired, Return detected',
    0x08 => 'On, Did not fire', # not charged up?
    0x09 => 'On, Fired',
    0x0d => 'On, Return not detected',
    0x0f => 'On, Return detected',
    0x10 => 'Off, Did not fire',
    0x14 => 'Off, Did not fire, Return not detected',
    0x18 => 'Auto, Did not fire',
    0x19 => 'Auto, Fired',
    0x1d => 'Auto, Fired, Return not detected',
    0x1f => 'Auto, Fired, Return detected',
    0x20 => 'No flash function',
    0x30 => 'Off, No flash function',
    0x41 => 'Fired, Red-eye reduction',
    0x45 => 'Fired, Red-eye reduction, Return not detected',
    0x47 => 'Fired, Red-eye reduction, Return detected',
    0x49 => 'On, Red-eye reduction',
    0x4d => 'On, Red-eye reduction, Return not detected',
    0x4f => 'On, Red-eye reduction, Return detected',
    0x50 => 'Off, Red-eye reduction',
    0x58 => 'Auto, Did not fire, Red-eye reduction',
    0x59 => 'Auto, Fired, Red-eye reduction',
    0x5d => 'Auto, Fired, Red-eye reduction, Return not detected',
    0x5f => 'Auto, Fired, Red-eye reduction, Return detected',
);

# TIFF Compression values
# (values with format "Xxxxx XXX Compressed" are used to identify RAW file types)
%compression = (
    1 => 'Uncompressed',
    2 => 'CCITT 1D',
    3 => 'T4/Group 3 Fax',
    4 => 'T6/Group 4 Fax',
    5 => 'LZW',
    6 => 'JPEG (old-style)', #3
    7 => 'JPEG', #4
    8 => 'Adobe Deflate', #3
    9 => 'JBIG B&W', #3
    10 => 'JBIG Color', #3
    99 => 'JPEG', #16
    262 => 'Kodak 262', #16
    32766 => 'Next', #3
    32767 => 'Sony ARW Compressed', #16
    32769 => 'Packed RAW', #PH (used by Epson, Nikon, Samsung)
    32770 => 'Samsung SRW Compressed', #PH
    32771 => 'CCIRLEW', #3
    32772 => 'Samsung SRW Compressed 2', #PH (NX3000,NXmini)
    32773 => 'PackBits',
    32809 => 'Thunderscan', #3
    32867 => 'Kodak KDC Compressed', #PH
    32895 => 'IT8CTPAD', #3
    32896 => 'IT8LW', #3
    32897 => 'IT8MP', #3
    32898 => 'IT8BL', #3
    32908 => 'PixarFilm', #3
    32909 => 'PixarLog', #3
    32946 => 'Deflate', #3
    32947 => 'DCS', #3
    34661 => 'JBIG', #3
    34676 => 'SGILog', #3
    34677 => 'SGILog24', #3
    34712 => 'JPEG 2000', #3
    34713 => 'Nikon NEF Compressed', #PH
    34715 => 'JBIG2 TIFF FX', #20
    34718 => 'Microsoft Document Imaging (MDI) Binary Level Codec', #18
    34719 => 'Microsoft Document Imaging (MDI) Progressive Transform Codec', #18
    34720 => 'Microsoft Document Imaging (MDI) Vector', #18
    34892 => 'Lossy JPEG', # (DNG 1.4)
    65000 => 'Kodak DCR Compressed', #PH
    65535 => 'Pentax PEF Compressed', #Jens
);

%photometricInterpretation = (
    0 => 'WhiteIsZero',
    1 => 'BlackIsZero',
    2 => 'RGB',
    3 => 'RGB Palette',
    4 => 'Transparency Mask',
    5 => 'CMYK',
    6 => 'YCbCr',
    8 => 'CIELab',
    9 => 'ICCLab', #3
    10 => 'ITULab', #3
    32803 => 'Color Filter Array', #2
    32844 => 'Pixar LogL', #3
    32845 => 'Pixar LogLuv', #3
    34892 => 'Linear Raw', #2
);

%orientation = (
    1 => 'Horizontal (normal)',
    2 => 'Mirror horizontal',
    3 => 'Rotate 180',
    4 => 'Mirror vertical',
    5 => 'Mirror horizontal and rotate 270 CW',
    6 => 'Rotate 90 CW',
    7 => 'Mirror horizontal and rotate 90 CW',
    8 => 'Rotate 270 CW',
);

%subfileType = (
    0 => 'Full-resolution Image',
    1 => 'Reduced-resolution image',
    2 => 'Single page of multi-page image',
    3 => 'Single page of multi-page reduced-resolution image',
    4 => 'Transparency mask',
    5 => 'Transparency mask of reduced-resolution image',
    6 => 'Transparency mask of multi-page image',
    7 => 'Transparency mask of reduced-resolution multi-page image',
    0x10001 => 'Alternate reduced-resolution image', # (DNG 1.2)
    0xffffffff => 'invalid', #(found in E5700 NEF's)
    BITMASK => {
        0 => 'Reduced resolution',
        1 => 'Single page',
        2 => 'Transparency mask',
        3 => 'TIFF/IT final page', #20
        4 => 'TIFF-FX mixed raster content', #20
    },
);

# PrintConv for parameter tags
%Image::ExifTool::Exif::printParameter = (
    PrintConv => {
        0 => 'Normal',
        OTHER => \&Image::ExifTool::Exif::PrintParameter,
    },
);

# convert DNG UTF-8 string values (may be string or int8u format)
my %utf8StringConv = (
    Writable => 'string',
    Format => 'string',
    ValueConv => '$self->Decode($val, "UTF8")',
    ValueConvInv => '$self->Encode($val,"UTF8")',
);

# ValueConv that makes long values binary type
my %longBin = (
    ValueConv => 'length($val) > 64 ? \$val : $val',
    ValueConvInv => '$val',
);

# PrintConv for SampleFormat (0x153)
my %sampleFormat = (
    1 => 'Unsigned',        # unsigned integer
    2 => 'Signed',          # two's complement signed integer
    3 => 'Float',           # IEEE floating point
    4 => 'Undefined',
    5 => 'Complex int',     # complex integer (ref 3)
    6 => 'Complex float',   # complex IEEE floating point (ref 3)
);

# main EXIF tag table
%Image::ExifTool::Exif::Main = (
    GROUPS => { 0 => 'EXIF', 1 => 'IFD0', 2 => 'Image'},
    WRITE_PROC => \&WriteExif,
    CHECK_PROC => \&CheckExif,
    WRITE_GROUP => 'ExifIFD',   # default write group
    SET_GROUP1 => 1, # set group1 name to directory name for all tags in table
    0x1 => {
        Name => 'InteropIndex',
        Description => 'Interoperability Index',
        Protected => 1,
        Writable => 'string',
        WriteGroup => 'InteropIFD',
        PrintConv => {
            R98 => 'R98 - DCF basic file (sRGB)',
            R03 => 'R03 - DCF option file (Adobe RGB)',
            THM => 'THM - DCF thumbnail file',
        },
    },
    0x2 => { #5
        Name => 'InteropVersion',
        Description => 'Interoperability Version',
        Protected => 1,
        Writable => 'undef',
        Mandatory => 1,
        WriteGroup => 'InteropIFD',
        RawConv => '$val=~s/\0+$//; $val',  # (some idiots add null terminators)
    },
    0x0b => { #PH
        Name => 'ProcessingSoftware',
        Writable => 'string',
        WriteGroup => 'IFD0',
        Notes => 'used by ACD Systems Digital Imaging',
    },
    0xfe => {
        Name => 'SubfileType',
        Notes => 'called NewSubfileType by the TIFF specification',
        Protected => 1,
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        # set priority directory if this is the full resolution image
        DataMember => 'SubfileType',
        RawConv => '$self->SetPriorityDir() if $val eq "0"; $$self{SubfileType} = $val',
        PrintConv => \%subfileType,
    },
    0xff => {
        Name => 'OldSubfileType',
        Notes => 'called SubfileType by the TIFF specification',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        # set priority directory if this is the full resolution image
        RawConv => '$self->SetPriorityDir() if $val eq "1"; $val',
        PrintConv => {
            1 => 'Full-resolution image',
            2 => 'Reduced-resolution image',
            3 => 'Single page of multi-page image',
        },
    },
    0x100 => {
        Name => 'ImageWidth',
        # even though Group 1 is set dynamically we need to register IFD1 once
        # so it will show up in the group lists
        Groups => { 1 => 'IFD1' },
        Protected => 1,
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        # Note: priority 0 tags automatically have their priority increased for the
        # priority direcory (the directory with a SubfileType of "Full-resolution image")
        Priority => 0,
    },
    0x101 => {
        Name => 'ImageHeight',
        Notes => 'called ImageLength by the EXIF spec.',
        Protected => 1,
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Priority => 0,
    },
    0x102 => {
        Name => 'BitsPerSample',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Count => -1, # can be 1 or 3: -1 means 'variable'
        Priority => 0,
    },
    0x103 => {
        Name => 'Compression',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Mandatory => 1,
        DataMember => 'Compression',
        SeparateTable => 'Compression',
        RawConv => q{
            Image::ExifTool::Exif::IdentifyRawFile($self, $val);
            return $$self{Compression} = $val;
        },
        PrintConv => \%compression,
        Priority => 0,
    },
    0x106 => {
        Name => 'PhotometricInterpretation',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => \%photometricInterpretation,
        Priority => 0,
    },
    0x107 => {
        Name => 'Thresholding',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => {
            1 => 'No dithering or halftoning',
            2 => 'Ordered dither or halftone',
            3 => 'Randomized dither',
        },
    },
    0x108 => {
        Name => 'CellWidth',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
    },
    0x109 => {
        Name => 'CellLength',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
    },
    0x10a => {
        Name => 'FillOrder',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => {
            1 => 'Normal',
            2 => 'Reversed',
        },
    },
    0x10d => {
        Name => 'DocumentName',
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0x10e => {
        Name => 'ImageDescription',
        Writable => 'string',
        WriteGroup => 'IFD0',
        Priority => 0,
    },
    0x10f => {
        Name => 'Make',
        Groups => { 2 => 'Camera' },
        Writable => 'string',
        WriteGroup => 'IFD0',
        DataMember => 'Make',
        # remove trailing blanks and save as an ExifTool member variable
        RawConv => '$val =~ s/\s+$//; $$self{Make} = $val',
        # NOTE: trailing "blanks" (spaces) are removed from all EXIF tags which
        # may be "unknown" (filled with spaces) according to the EXIF spec.
        # This allows conditional replacement with "exiftool -TAG-= -TAG=VALUE".
        # - also removed are any other trailing whitespace characters
    },
    0x110 => {
        Name => 'Model',
        Description => 'Camera Model Name',
        Groups => { 2 => 'Camera' },
        Writable => 'string',
        WriteGroup => 'IFD0',
        DataMember => 'Model',
        # remove trailing blanks and save as an ExifTool member variable
        RawConv => '$val =~ s/\s+$//; $$self{Model} = $val',
    },
    0x111 => [
        {
            Condition => q[
                $$self{TIFF_TYPE} eq 'MRW' and $$self{DIR_NAME} eq 'IFD0' and
                $$self{Model} =~ /^DiMAGE A200/
            ],
            Name => 'StripOffsets',
            IsOffset => 1,
            OffsetPair => 0x117,  # point to associated byte counts
            # A200 stores this information in the wrong byte order!!
            ValueConv => '$val=join(" ",unpack("N*",pack("V*",split(" ",$val))));\$val',
            ByteOrder => 'LittleEndian',
        },
        {
            # (APP1 IFD2 is for Leica JPEG preview)
            Condition => q[
                not ($$self{TIFF_TYPE} eq 'CR2' and $$self{DIR_NAME} eq 'IFD0') and
                not ($$self{TIFF_TYPE} eq 'DNG' and $$self{Compression} eq '7' and $$self{SubfileType} ne '0') and
                not ($$self{TIFF_TYPE} eq 'APP1' and $$self{DIR_NAME} eq 'IFD2')
            ],
            Name => 'StripOffsets',
            IsOffset => 1,
            OffsetPair => 0x117,  # point to associated byte counts
            ValueConv => 'length($val) > 32 ? \$val : $val',
        },
        {
            # PreviewImageStart in IFD0 of CR2 images
            Condition => '$$self{TIFF_TYPE} eq "CR2"',
            Name => 'PreviewImageStart',
            IsOffset => 1,
            OffsetPair => 0x117,
            Notes => q{
                called StripOffsets in most locations, but it is PreviewImageStart in IFD0
                of CR2 images and various IFD's of DNG images except for SubIFD2 where it is
                JpgFromRawStart
            },
            DataTag => 'PreviewImage',
            Writable => 'int32u',
            WriteGroup => 'IFD0',
            Protected => 2,
            Permanent => 1,
        },
        {
            # PreviewImageStart in various IFD's of DNG images except SubIFD2
            Condition => '$$self{DIR_NAME} ne "SubIFD2"',
            Name => 'PreviewImageStart',
            IsOffset => 1,
            OffsetPair => 0x117,
            DataTag => 'PreviewImage',
            Writable => 'int32u',
            WriteGroup => 'All',    # (writes to specific group of associated Composite tag)
            Protected => 2,
            Permanent => 1,
        },
        {
            # JpgFromRawStart in various IFD's of DNG images except SubIFD2
            Name => 'JpgFromRawStart',
            IsOffset => 1,
            OffsetPair => 0x117,
            DataTag => 'JpgFromRaw',
            Writable => 'int32u',
            WriteGroup => 'SubIFD2',
            Protected => 2,
            Permanent => 1,
        },
    ],
    0x112 => {
        Name => 'Orientation',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => \%orientation,
        Priority => 0,  # so PRIORITY_DIR takes precedence
    },
    0x115 => {
        Name => 'SamplesPerPixel',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Priority => 0,
    },
    0x116 => {
        Name => 'RowsPerStrip',
        Protected => 1,
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Priority => 0,
    },
    0x117 => [
        {
            Condition => q[
                $$self{TIFF_TYPE} eq 'MRW' and $$self{DIR_NAME} eq 'IFD0' and
                $$self{Model} =~ /^DiMAGE A200/
            ],
            Name => 'StripByteCounts',
            OffsetPair => 0x111,   # point to associated offset
            # A200 stores this information in the wrong byte order!!
            ValueConv => '$val=join(" ",unpack("N*",pack("V*",split(" ",$val))));\$val',
            ByteOrder => 'LittleEndian',
        },
        {
            # (APP1 IFD2 is for Leica JPEG preview)
            Condition => q[
                not ($$self{TIFF_TYPE} eq 'CR2' and $$self{DIR_NAME} eq 'IFD0') and
                not ($$self{TIFF_TYPE} eq 'DNG' and $$self{Compression} eq '7' and $$self{SubfileType} ne '0') and
                not ($$self{TIFF_TYPE} eq 'APP1' and $$self{DIR_NAME} eq 'IFD2')
            ],
            Name => 'StripByteCounts',
            OffsetPair => 0x111,   # point to associated offset
            ValueConv => 'length($val) > 32 ? \$val : $val',
        },
        {
            # PreviewImageLength in IFD0 of CR2 images
            Condition => '$$self{TIFF_TYPE} eq "CR2"',
            Name => 'PreviewImageLength',
            OffsetPair => 0x111,
            Notes => q{
                called StripByteCounts in most locations, but it is PreviewImageLength in
                IFD0 of CR2 images and various IFD's of DNG images except for SubIFD2 where
                it is JpgFromRawLength
            },
            DataTag => 'PreviewImage',
            Writable => 'int32u',
            WriteGroup => 'IFD0',
            Protected => 2,
            Permanent => 1,
        },
        {
            # PreviewImageLength in various IFD's of DNG images except SubIFD2
            Condition => '$$self{DIR_NAME} ne "SubIFD2"',
            Name => 'PreviewImageLength',
            OffsetPair => 0x111,
            DataTag => 'PreviewImage',
            Writable => 'int32u',
            WriteGroup => 'All',    # (writes to specific group of associated Composite tag)
            Protected => 2,
            Permanent => 1,
        },
        {
            # JpgFromRawLength in SubIFD2 of DNG images
            Name => 'JpgFromRawLength',
            OffsetPair => 0x111,
            DataTag => 'JpgFromRaw',
            Writable => 'int32u',
            WriteGroup => 'SubIFD2',
            Protected => 2,
            Permanent => 1,
        },
    ],
    0x118 => {
        Name => 'MinSampleValue',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
    },
    0x119 => {
        Name => 'MaxSampleValue',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
    },
    0x11a => {
        Name => 'XResolution',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Mandatory => 1,
        Priority => 0,  # so PRIORITY_DIR takes precedence
    },
    0x11b => {
        Name => 'YResolution',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Mandatory => 1,
        Priority => 0,
    },
    0x11c => {
        Name => 'PlanarConfiguration',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => {
            1 => 'Chunky',
            2 => 'Planar',
        },
        Priority => 0,
    },
    0x11d => {
        Name => 'PageName',
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0x11e => {
        Name => 'XPosition',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
    },
    0x11f => {
        Name => 'YPosition',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
    },
    # FreeOffsets/FreeByteCounts are used by Ricoh for RMETA information
    # in TIFF images (not yet supported)
    0x120 => {
        Name => 'FreeOffsets',
        IsOffset => 1,
        OffsetPair => 0x121,
        ValueConv => 'length($val) > 32 ? \$val : $val',
    },
    0x121 => {
        Name => 'FreeByteCounts',
        OffsetPair => 0x120,
        ValueConv => 'length($val) > 32 ? \$val : $val',
    },
    0x122 => {
        Name => 'GrayResponseUnit',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => { #3
            1 => 0.1,
            2 => 0.001,
            3 => 0.0001,
            4 => 0.00001,
            5 => 0.000001,
        },
    },
    0x123 => {
        Name => 'GrayResponseCurve',
        Binary => 1,
    },
    0x124 => {
        Name => 'T4Options',
        PrintConv => { BITMASK => {
            0 => '2-Dimensional encoding',
            1 => 'Uncompressed',
            2 => 'Fill bits added',
        } }, #3
    },
    0x125 => {
        Name => 'T6Options',
        PrintConv => { BITMASK => {
            1 => 'Uncompressed',
        } }, #3
    },
    0x128 => {
        Name => 'ResolutionUnit',
        Notes => 'the value 1 is not standard EXIF',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Mandatory => 1,
        PrintConv => {
            1 => 'None',
            2 => 'inches',
            3 => 'cm',
        },
        Priority => 0,
    },
    0x129 => {
        Name => 'PageNumber',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Count => 2,
    },
    0x12c => 'ColorResponseUnit', #9
    0x12d => {
        Name => 'TransferFunction',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Count => 768,
        Binary => 1,
    },
    0x131 => {
        Name => 'Software',
        Writable => 'string',
        WriteGroup => 'IFD0',
        RawConv => '$val =~ s/\s+$//; $val', # trim trailing blanks
    },
    0x132 => {
        Name => 'ModifyDate',
        Groups => { 2 => 'Time' },
        Notes => 'called DateTime by the EXIF spec.',
        Writable => 'string',
        Shift => 'Time',
        WriteGroup => 'IFD0',
        Validate => 'ValidateExifDate($val)',
        PrintConv => '$self->ConvertDateTime($val)',
        PrintConvInv => '$self->InverseDateTime($val,0)',
    },
    0x13b => {
        Name => 'Artist',
        Groups => { 2 => 'Author' },
        Notes => 'becomes a list-type tag when the MWG module is loaded',
        Writable => 'string',
        WriteGroup => 'IFD0',
        RawConv => '$val =~ s/\s+$//; $val', # trim trailing blanks
    },
    0x13c => {
        Name => 'HostComputer',
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0x13d => {
        Name => 'Predictor',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => {
            1 => 'None',
            2 => 'Horizontal differencing',
        },
    },
    0x13e => {
        Name => 'WhitePoint',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => 2,
    },
    0x13f => {
        Name => 'PrimaryChromaticities',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => 6,
        Priority => 0,
    },
    0x140 => {
        Name => 'ColorMap',
        Format => 'binary',
        Binary => 1,
    },
    0x141 => {
        Name => 'HalftoneHints',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Count => 2,
    },
    0x142 => {
        Name => 'TileWidth',
        Protected => 1,
        Writable => 'int32u',
        WriteGroup => 'IFD0',
    },
    0x143 => {
        Name => 'TileLength',
        Protected => 1,
        Writable => 'int32u',
        WriteGroup => 'IFD0',
    },
    0x144 => {
        Name => 'TileOffsets',
        IsOffset => 1,
        OffsetPair => 0x145,
        ValueConv => 'length($val) > 32 ? \$val : $val',
    },
    0x145 => {
        Name => 'TileByteCounts',
        OffsetPair => 0x144,
        ValueConv => 'length($val) > 32 ? \$val : $val',
    },
    0x146 => 'BadFaxLines', #3
    0x147 => { #3
        Name => 'CleanFaxData',
        PrintConv => {
            0 => 'Clean',
            1 => 'Regenerated',
            2 => 'Unclean',
        },
    },
    0x148 => 'ConsecutiveBadFaxLines', #3
    0x14a => [
        {
            Name => 'SubIFD',
            # use this opportunity to identify an ARW image, and if so we
            # must decide if this is a SubIFD or the A100 raw data
            # (use SubfileType, Compression and FILE_TYPE to identify ARW/SR2,
            # then call SetARW to finish the job)
            Condition => q{
                $$self{DIR_NAME} ne 'IFD0' or $$self{FILE_TYPE} ne 'TIFF' or
                $$self{Make} !~ /^SONY/ or
                not $$self{SubfileType} or $$self{SubfileType} != 1 or
                not $$self{Compression} or $$self{Compression} != 6 or
                not require Image::ExifTool::Sony or
                Image::ExifTool::Sony::SetARW($self, $valPt)
            },
            Groups => { 1 => 'SubIFD' },
            Flags => 'SubIFD',
            SubDirectory => {
                Start => '$val',
                MaxSubdirs => 10, # (have seen 5 in a DNG 1.4 image)
            },
        },
        { #16
            Name => 'A100DataOffset',
            Notes => 'the data offset in original Sony DSLR-A100 ARW images',
            DataMember => 'A100DataOffset',
            RawConv => '$$self{A100DataOffset} = $val',
            WriteGroup => 'IFD0', # (only for Validate)
            IsOffset => 1,
            Protected => 2,
        },
    ],
    0x14c => {
        Name => 'InkSet',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => { #3
            1 => 'CMYK',
            2 => 'Not CMYK',
        },
    },
    0x14d => 'InkNames', #3
    0x14e => 'NumberofInks', #3
    0x150 => 'DotRange',
    0x151 => {
        Name => 'TargetPrinter',
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0x152 => {
        Name => 'ExtraSamples',
        PrintConv => { #20
            0 => 'Unspecified',
            1 => 'Associated Alpha',
            2 => 'Unassociated Alpha',
        },
    },
    0x153 => {
        Name => 'SampleFormat',
        Notes => 'SamplesPerPixel values',
        WriteGroup => 'SubIFD', # (only for Validate)
        PrintConvColumns => 2,
        PrintConv => [ \%sampleFormat, \%sampleFormat, \%sampleFormat, \%sampleFormat ],
    },
    0x154 => 'SMinSampleValue',
    0x155 => 'SMaxSampleValue',
    0x156 => 'TransferRange',
    0x157 => 'ClipPath', #3
    0x158 => 'XClipPathUnits', #3
    0x159 => 'YClipPathUnits', #3
    0x15a => { #3
        Name => 'Indexed',
        PrintConv => { 0 => 'Not indexed', 1 => 'Indexed' },
    },
    0x15b => {
        Name => 'JPEGTables',
        Binary => 1,
    },
    0x15f => { #10
        Name => 'OPIProxy',
        PrintConv => {
            0 => 'Higher resolution image does not exist',
            1 => 'Higher resolution image exists',
        },
    },
    # 0x181 => 'Decode', #20 (typo! - should be 0x1b1, ref 21)
    # 0x182 => 'DefaultImageColor', #20 (typo! - should be 0x1b2, ref 21)
    0x190 => { #3
        Name => 'GlobalParametersIFD',
        Groups => { 1 => 'GlobParamIFD' },
        Flags => 'SubIFD',
        SubDirectory => {
            DirName => 'GlobParamIFD',
            Start => '$val',
            MaxSubdirs => 1,
        },
    },
    0x191 => { #3
        Name => 'ProfileType',
        PrintConv => { 0 => 'Unspecified', 1 => 'Group 3 FAX' },
    },
    0x192 => { #3
        Name => 'FaxProfile',
        PrintConv => {
            0 => 'Unknown',
            1 => 'Minimal B&W lossless, S',
            2 => 'Extended B&W lossless, F',
            3 => 'Lossless JBIG B&W, J',
            4 => 'Lossy color and grayscale, C',
            5 => 'Lossless color and grayscale, L',
            6 => 'Mixed raster content, M',
            7 => 'Profile T', #20
            255 => 'Multi Profiles', #20
        },
    },
    0x193 => { #3
        Name => 'CodingMethods',
        PrintConv => { BITMASK => {
            0 => 'Unspecified compression',
            1 => 'Modified Huffman',
            2 => 'Modified Read',
            3 => 'Modified MR',
            4 => 'JBIG',
            5 => 'Baseline JPEG',
            6 => 'JBIG color',
        } },
    },
    0x194 => 'VersionYear', #3
    0x195 => 'ModeNumber', #3
    0x1b1 => 'Decode', #3
    0x1b2 => 'DefaultImageColor', #3 (changed to ImageBaseColor, ref 21)
    0x1b3 => 'T82Options', #20
    0x1b5 => { #19
        Name => 'JPEGTables',
        Binary => 1,
    },
    0x200 => {
        Name => 'JPEGProc',
        PrintConv => {
            1 => 'Baseline',
            14 => 'Lossless',
        },
    },
    0x201 => [
        {
            Name => 'ThumbnailOffset',
            Notes => q{
                ThumbnailOffset in IFD1 of JPEG and some TIFF-based images, IFD0 of MRW
                images and AVI and MOV videos, and the SubIFD in IFD1 of SRW images;
                PreviewImageStart in MakerNotes and IFD0 of ARW and SR2 images;
                JpgFromRawStart in SubIFD of NEF images and IFD2 of PEF images; and
                OtherImageStart in everything else
            },
            # thumbnail is found in IFD1 of JPEG and TIFF images, and
            # IFD0 of EXIF information in FujiFilm AVI (RIFF) and MOV videos
            Condition => q{
                # recognize NRW file from a JPEG-compressed thumbnail in IFD0
                if ($$self{TIFF_TYPE} eq 'NEF' and $$self{DIR_NAME} eq 'IFD0' and $$self{Compression} == 6) {
                    $self->OverrideFileType($$self{TIFF_TYPE} = 'NRW');
                }
                $$self{DIR_NAME} eq 'IFD1' or
                ($$self{DIR_NAME} eq 'IFD0' and $$self{FILE_TYPE} =~ /^(RIFF|MOV)$/)
            },
            IsOffset => 1,
            OffsetPair => 0x202,
            DataTag => 'ThumbnailImage',
            Writable => 'int32u',
            WriteGroup => 'IFD1',
            # according to the EXIF spec. a JPEG-compressed thumbnail image may not
            # be stored in a TIFF file, but these TIFF-based RAW image formats
            # use IFD1 for a JPEG-compressed thumbnail:  CR2, ARW, SR2 and PEF.
            # (SRF also stores a JPEG image in IFD1, but it is actually a preview
            # and we don't yet write SRF anyway)
            WriteCondition => q{
                $$self{FILE_TYPE} ne "TIFF" or
                $$self{TIFF_TYPE} =~ /^(CR2|ARW|SR2|PEF)$/
            },
            Protected => 2,
        },
        {
            Name => 'ThumbnailOffset',
            # thumbnail in IFD0 of MRW images (Minolta A200)
            # and IFD0 of NRW images (Nikon Coolpix P6000,P7000,P7100)
            Condition => '$$self{DIR_NAME} eq "IFD0" and $$self{TIFF_TYPE} =~ /^(MRW|NRW)$/',
            IsOffset => 1,
            OffsetPair => 0x202,
            # A200 uses the wrong base offset for this pointer!!
            WrongBase => '$$self{Model} =~ /^DiMAGE A200/ ? $$self{MRW_WrongBase} : undef',
            DataTag => 'ThumbnailImage',
            Writable => 'int32u',
            WriteGroup => 'IFD0',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'ThumbnailOffset',
            # in SubIFD of IFD1 in Samsung SRW images
            Condition => q{
                $$self{TIFF_TYPE} eq 'SRW' and $$self{DIR_NAME} eq 'SubIFD' and
                $$self{PATH}[-2] eq 'IFD1'
            },
            IsOffset => 1,
            OffsetPair => 0x202,
            DataTag => 'ThumbnailImage',
            Writable => 'int32u',
            WriteGroup => 'SubIFD',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'PreviewImageStart',
            Condition => '$$self{DIR_NAME} eq "MakerNotes"',
            IsOffset => 1,
            OffsetPair => 0x202,
            DataTag => 'PreviewImage',
            Writable => 'int32u',
            WriteGroup => 'MakerNotes',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'PreviewImageStart',
            # PreviewImage in IFD0 of ARW and SR2 files for all models
            Condition => '$$self{DIR_NAME} eq "IFD0" and $$self{TIFF_TYPE} =~ /^(ARW|SR2)$/',
            IsOffset => 1,
            OffsetPair => 0x202,
            DataTag => 'PreviewImage',
            Writable => 'int32u',
            WriteGroup => 'IFD0',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'JpgFromRawStart',
            Condition => '$$self{DIR_NAME} eq "SubIFD"',
            IsOffset => 1,
            OffsetPair => 0x202,
            DataTag => 'JpgFromRaw',
            Writable => 'int32u',
            WriteGroup => 'SubIFD',
            # JpgFromRaw is in SubIFD of NEF, NRW and SRW files
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'JpgFromRawStart',
            Condition => '$$self{DIR_NAME} eq "IFD2"',
            IsOffset => 1,
            OffsetPair => 0x202,
            DataTag => 'JpgFromRaw',
            Writable => 'int32u',
            WriteGroup => 'IFD2',
            # JpgFromRaw is in IFD2 of PEF files
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'OtherImageStart',
            Condition => '$$self{DIR_NAME} eq "SubIFD1"',
            IsOffset => 1,
            OffsetPair => 0x202,
            DataTag => 'OtherImage',
            Writable => 'int32u',
            WriteGroup => 'SubIFD1',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'OtherImageStart',
            Condition => '$$self{DIR_NAME} eq "SubIFD2"',
            IsOffset => 1,
            OffsetPair => 0x202,
            DataTag => 'OtherImage',
            Writable => 'int32u',
            WriteGroup => 'SubIFD2',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'OtherImageStart',
            IsOffset => 1,
            OffsetPair => 0x202,
        },
    ],
    0x202 => [
        {
            Name => 'ThumbnailLength',
            Notes => q{
                ThumbnailLength in IFD1 of JPEG and some TIFF-based images, IFD0 of MRW
                images and AVI and MOV videos, and the SubIFD in IFD1 of SRW images;
                PreviewImageLength in MakerNotes and IFD0 of ARW and SR2 images;
                JpgFromRawLength in SubIFD of NEF images, and IFD2 of PEF images; and
                OtherImageLength in everything else
            },
            Condition => q{
                $$self{DIR_NAME} eq 'IFD1' or
                ($$self{DIR_NAME} eq 'IFD0' and $$self{FILE_TYPE} =~ /^(RIFF|MOV)$/)
            },
            OffsetPair => 0x201,
            DataTag => 'ThumbnailImage',
            Writable => 'int32u',
            WriteGroup => 'IFD1',
            WriteCondition => q{
                $$self{FILE_TYPE} ne "TIFF" or
                $$self{TIFF_TYPE} =~ /^(CR2|ARW|SR2|PEF)$/
            },
            Protected => 2,
        },
        {
            Name => 'ThumbnailLength',
            # thumbnail in IFD0 of MRW images (Minolta A200)
            # and IFD0 of NRW images (Nikon Coolpix P6000,P7000,P7100)
            Condition => '$$self{DIR_NAME} eq "IFD0" and $$self{TIFF_TYPE} =~ /^(MRW|NRW)$/',
            OffsetPair => 0x201,
            DataTag => 'ThumbnailImage',
            Writable => 'int32u',
            WriteGroup => 'IFD0',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'ThumbnailLength',
            # in SubIFD of IFD1 in Samsung SRW images
            Condition => q{
                $$self{TIFF_TYPE} eq 'SRW' and $$self{DIR_NAME} eq 'SubIFD' and
                $$self{PATH}[-2] eq 'IFD1'
            },
            OffsetPair => 0x201,
            DataTag => 'ThumbnailImage',
            Writable => 'int32u',
            WriteGroup => 'SubIFD',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'PreviewImageLength',
            Condition => '$$self{DIR_NAME} eq "MakerNotes"',
            OffsetPair => 0x201,
            DataTag => 'PreviewImage',
            Writable => 'int32u',
            WriteGroup => 'MakerNotes',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'PreviewImageLength',
            # PreviewImage in IFD0 of ARW and SR2 files for all models
            Condition => '$$self{DIR_NAME} eq "IFD0" and $$self{TIFF_TYPE} =~ /^(ARW|SR2)$/',
            OffsetPair => 0x201,
            DataTag => 'PreviewImage',
            Writable => 'int32u',
            WriteGroup => 'IFD0',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'JpgFromRawLength',
            Condition => '$$self{DIR_NAME} eq "SubIFD"',
            OffsetPair => 0x201,
            DataTag => 'JpgFromRaw',
            Writable => 'int32u',
            WriteGroup => 'SubIFD',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'JpgFromRawLength',
            Condition => '$$self{DIR_NAME} eq "IFD2"',
            OffsetPair => 0x201,
            DataTag => 'JpgFromRaw',
            Writable => 'int32u',
            WriteGroup => 'IFD2',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'OtherImageLength',
            Condition => '$$self{DIR_NAME} eq "SubIFD1"',
            OffsetPair => 0x201,
            DataTag => 'OtherImage',
            Writable => 'int32u',
            WriteGroup => 'SubIFD1',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'OtherImageLength',
            Condition => '$$self{DIR_NAME} eq "SubIFD2"',
            OffsetPair => 0x201,
            DataTag => 'OtherImage',
            Writable => 'int32u',
            WriteGroup => 'SubIFD2',
            Protected => 2,
            Permanent => 1,
        },
        {
            Name => 'OtherImageLength',
            OffsetPair => 0x201,
        },
    ],
    0x203 => 'JPEGRestartInterval',
    0x205 => 'JPEGLosslessPredictors',
    0x206 => 'JPEGPointTransforms',
    0x207 => {
        Name => 'JPEGQTables',
        IsOffset => 1,
        # this tag is not supported for writing, so define an
        # invalid offset pair to cause a "No size tag" error to be
        # generated if we try to write a file containing this tag
        OffsetPair => -1,
    },
    0x208 => {
        Name => 'JPEGDCTables',
        IsOffset => 1,
        OffsetPair => -1, # (see comment for JPEGQTables)
    },
    0x209 => {
        Name => 'JPEGACTables',
        IsOffset => 1,
        OffsetPair => -1, # (see comment for JPEGQTables)
    },
    0x211 => {
        Name => 'YCbCrCoefficients',
        Protected => 1,
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => 3,
        Priority => 0,
    },
    0x212 => {
        Name => 'YCbCrSubSampling',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Count => 2,
        PrintConvColumns => 2,
        PrintConv => \%Image::ExifTool::JPEG::yCbCrSubSampling,
        Priority => 0,
    },
    0x213 => {
        Name => 'YCbCrPositioning',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Mandatory => 1,
        PrintConv => {
            1 => 'Centered',
            2 => 'Co-sited',
        },
        Priority => 0,
    },
    0x214 => {
        Name => 'ReferenceBlackWhite',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => 6,
        Priority => 0,
    },
    0x22f => 'StripRowCounts',
    0x2bc => {
        Name => 'ApplicationNotes', # (writable directory!)
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0', # (only for Validate)
        Flags => [ 'Binary', 'Protected' ],
        # this could be an XMP block
        SubDirectory => {
            DirName => 'XMP',
            TagTable => 'Image::ExifTool::XMP::Main',
        },
    },
    0x3e7 => 'USPTOMiscellaneous', #20
    0x1000 => { #5
        Name => 'RelatedImageFileFormat',
        Protected => 1,
        Writable => 'string',
        WriteGroup => 'InteropIFD',
    },
    0x1001 => { #5
        Name => 'RelatedImageWidth',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'InteropIFD',
    },
    0x1002 => { #5
        Name => 'RelatedImageHeight',
        Notes => 'called RelatedImageLength by the DCF spec.',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'InteropIFD',
    },
    # (0x474x tags written by MicrosoftPhoto)
    0x4746 => { #PH
        Name => 'Rating',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Avoid => 1,
    },
    0x4747 => { # (written by Digital Image Pro)
        Name => 'XP_DIP_XML',
        Format => 'undef',
        # the following reference indicates this is Unicode:
        # http://social.msdn.microsoft.com/Forums/en-US/isvvba/thread/ce6edcbb-8fc2-40c6-ad98-85f5d835ddfb
        ValueConv => '$self->Decode($val,"UCS2","II")',
    },
    0x4748 => {
        Name => 'StitchInfo',
        SubDirectory => {
            TagTable => 'Image::ExifTool::Microsoft::Stitch',
            ByteOrder => 'LittleEndian', #PH (NC)
        },
    },
    0x4749 => { #PH
        Name => 'RatingPercent',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Avoid => 1,
    },
    0x7000 => { #JR
        Name => 'SonyRawFileType',
        # (only valid if Sony:FileFormat >= ARW 2.0, ref IB)
        # Writable => 'int16u', (don't allow writes for now)
        PrintConv => {
            0 => 'Sony Uncompressed 14-bit RAW',
            1 => 'Sony Uncompressed 12-bit RAW', #IB
            2 => 'Sony Compressed RAW', # (lossy, ref IB)
            3 => 'Sony Lossless Compressed RAW', #IB
        },
    },
    # 0x7001 - int16u[1] (in SubIFD of Sony ARW images) - values: 0,1
    0x7010 => { #IB
        Name => 'SonyToneCurve',
        # int16u[4] (in SubIFD of Sony ARW images -- don't allow writes for now)
        # - only the middle 4 points are stored (lower comes from black level,
        #   and upper from data maximum)
    },
    # 0x7011 - int16u[4] (in SubIFD of Sony ARW images) - values: "0 4912 8212 12287","4000 7200 10050 12075"
    # 0x7020 - int32u[1] (in SubIFD of Sony ARW images) - values: 0,3
    0x7031 => {
        Name => 'VignettingCorrection',
        Notes => 'found in Sony ARW images',
        Protected => 1,
        Writable => 'int16s',
        WriteGroup => 'SubIFD',
        PrintConv => {
            256 => 'Off',
            257 => 'Auto',
            511 => 'No correction params available',
        },
    },
    0x7032 => {
        Name => 'VignettingCorrParams', #forum7640
        Notes => 'found in Sony ARW images',
        Protected => 1,
        Writable => 'int16s',
        WriteGroup => 'SubIFD',
        Count => 17,
    },
    0x7034 => {
        Name => 'ChromaticAberrationCorrection',
        Notes => 'found in Sony ARW images',
        Protected => 1,
        Writable => 'int16s',
        WriteGroup => 'SubIFD',
        PrintConv => {
            0 => 'Off',
            1 => 'Auto',
            255 => 'No correction params available',
        },
    },
    0x7035 => {
        Name => 'ChromaticAberrationCorrParams', #forum6509
        Notes => 'found in Sony ARW images',
        Protected => 1,
        Writable => 'int16s',
        WriteGroup => 'SubIFD',
        Count => 33,
    },
    0x7036 => {
        Name => 'DistortionCorrection',
        Notes => 'found in Sony ARW images',
        Protected => 1,
        Writable => 'int16s',
        WriteGroup => 'SubIFD',
        PrintConv => {
            0 => 'Off',
            1 => 'Auto',
            17 => 'Auto fixed by lens',
            255 => 'No correction params available',
        },
    },
    0x7037 => {
        Name => 'DistortionCorrParams', #forum6509
        Notes => 'found in Sony ARW images',
        Protected => 1,
        Writable => 'int16s',
        WriteGroup => 'SubIFD',
        Count => 17,
    },
    0x800d => 'ImageID', #10
    0x80a3 => { Name => 'WangTag1', Binary => 1 }, #20
    0x80a4 => { Name => 'WangAnnotation', Binary => 1 },
    0x80a5 => { Name => 'WangTag3', Binary => 1 }, #20
    0x80a6 => { #20
        Name => 'WangTag4',
        PrintConv => 'length($val) <= 64 ? $val : \$val',
    },
    # tags 0x80b8-0x80bc are registered to Island Graphics
    0x80b9 => 'ImageReferencePoints', #29
    0x80ba => 'RegionXformTackPoint', #29
    0x80bb => 'WarpQuadrilateral', #29
    0x80bc => 'AffineTransformMat', #29
    0x80e3 => 'Matteing', #9
    0x80e4 => 'DataType', #9
    0x80e5 => 'ImageDepth', #9
    0x80e6 => 'TileDepth', #9
    # tags 0x8214-0x8219 are registered to Pixar
    0x8214 => 'ImageFullWidth', #29
    0x8215 => 'ImageFullHeight', #29
    0x8216 => 'TextureFormat', #29
    0x8217 => 'WrapModes', #29
    0x8218 => 'FovCot', #29
    0x8219 => 'MatrixWorldToScreen', #29
    0x821a => 'MatrixWorldToCamera', #29
    0x827d => 'Model2', #29 (Eastman Kodak)
    0x828d => { #12
        Name => 'CFARepeatPatternDim',
        Protected => 1,
        Writable => 'int16u',
        WriteGroup => 'SubIFD',
        Count => 2,
    },
    0x828e => {
        Name => 'CFAPattern2', #12
        Format => 'int8u',  # (written incorrectly as 'undef' in Nikon NRW images)
        Protected => 1,
        Writable => 'int8u',
        WriteGroup => 'SubIFD',
        Count => -1,
    },
    0x828f => { #12
        Name => 'BatteryLevel',
        Groups => { 2 => 'Camera' },
    },
    0x8290 => {
        Name => 'KodakIFD',
        Groups => { 1 => 'KodakIFD' },
        Flags => 'SubIFD',
        Notes => 'used in various types of Kodak images',
        SubDirectory => {
            TagTable => 'Image::ExifTool::Kodak::IFD',
            DirName => 'KodakIFD',
            Start => '$val',
            MaxSubdirs => 1,
        },
    },
    0x8298 => {
        Name => 'Copyright',
        Groups => { 2 => 'Author' },
        Format => 'undef',
        Writable => 'string',
        WriteGroup => 'IFD0',
        RawConvInv => '$val . "\0"',
        PrintConvInv => sub {
            my ($val, $self) = @_;
            # encode if necessary (not automatic because Format is 'undef')
            my $enc = $self->Options('CharsetEXIF');
            $val = $self->Encode($val,$enc) if $enc and $val !~ /\0/;
            if ($val =~ /(.*?)\s*[\n\r]+\s*(.*)/s) {
                return $1 unless length $2;
                # photographer copyright set to ' ' if it doesn't exist, according to spec.
                return((length($1) ? $1 : ' ') . "\0" . $2);
            }
            return $val;
        },
        Notes => q{
            may contain copyright notices for photographer and editor, separated by a
            newline.  As per the EXIF specification, the newline is replaced by a null
            byte when writing to file, but this may be avoided by disabling the print
            conversion
        },
        # internally the strings are separated by a null character in this format:
        # Photographer only: photographer + NULL
        # Both:              photographer + NULL + editor + NULL
        # Editor only:       SPACE + NULL + editor + NULL
        # (this is done as a RawConv so conditional replaces will work properly)
        RawConv => sub {
            my ($val, $self) = @_;
            $val =~ s/ *\0/\n/;  # translate first NULL to a newline, removing trailing blanks
            $val =~ s/ *\0.*//s; # truncate at second NULL and remove trailing blanks
            $val =~ s/\n$//;     # remove trailing newline if it exists
            # decode if necessary (note: this is the only non-'string' EXIF value like this)
            my $enc = $self->Options('CharsetEXIF');
            $val = $self->Decode($val,$enc) if $enc;
            return $val;
        },
    },
    0x829a => {
        Name => 'ExposureTime',
        Writable => 'rational64u',
        PrintConv => 'Image::ExifTool::Exif::PrintExposureTime($val)',
        PrintConvInv => '$val',
    },
    0x829d => {
        Name => 'FNumber',
        Writable => 'rational64u',
        PrintConv => 'Image::ExifTool::Exif::PrintFNumber($val)',
        PrintConvInv => '$val',
    },
    0x82a5 => { #3
        Name => 'MDFileTag',
        Notes => 'tags 0x82a5-0x82ac are used in Molecular Dynamics GEL files',
    },
    0x82a6 => 'MDScalePixel', #3
    0x82a7 => 'MDColorTable', #3
    0x82a8 => 'MDLabName', #3
    0x82a9 => 'MDSampleInfo', #3
    0x82aa => 'MDPrepDate', #3
    0x82ab => 'MDPrepTime', #3
    0x82ac => 'MDFileUnits', #3
    0x830e => 'PixelScale', #30
    0x8335 => 'AdventScale', #20
    0x8336 => 'AdventRevision', #20
    0x835c => 'UIC1Tag', #23
    0x835d => 'UIC2Tag', #23
    0x835e => 'UIC3Tag', #23
    0x835f => 'UIC4Tag', #23
    0x83bb => { #12
        Name => 'IPTC-NAA', # (writable directory! -- but see note below)
        # this should actually be written as 'undef' (see
        # http://www.awaresystems.be/imaging/tiff/tifftags/iptc.html),
        # but Photoshop writes it as int32u and Nikon Capture won't read
        # anything else, so we do the same thing here...  Doh!
        Format => 'undef',      # convert binary values as undef
        Writable => 'int32u',   # but write int32u format code in IFD
        WriteGroup => 'IFD0',
        Flags => [ 'Binary', 'Protected' ],
        SubDirectory => {
            DirName => 'IPTC',
            TagTable => 'Image::ExifTool::IPTC::Main',
        },
        # Note: This directory may be written as a block via the IPTC-NAA tag,
        # but this technique is not recommended.  Instead, it is better to
        # write the Extra IPTC tag and let ExifTool decide where it should go.
    },
    0x847e => 'IntergraphPacketData', #3
    0x847f => 'IntergraphFlagRegisters', #3
    0x8480 => 'IntergraphMatrix', #30
    0x8481 => 'INGRReserved', #20
    0x8482 => { #30
        Name => 'ModelTiePoint',
        Groups => { 2 => 'Location' },
    },
    0x84e0 => 'Site', #9
    0x84e1 => 'ColorSequence', #9
    0x84e2 => 'IT8Header', #9
    0x84e3 => { #9
        Name => 'RasterPadding',
        PrintConv => { #20
            0 => 'Byte',
            1 => 'Word',
            2 => 'Long Word',
            9 => 'Sector',
            10 => 'Long Sector',
        },
    },
    0x84e4 => 'BitsPerRunLength', #9
    0x84e5 => 'BitsPerExtendedRunLength', #9
    0x84e6 => 'ColorTable', #9
    0x84e7 => { #9
        Name => 'ImageColorIndicator',
        PrintConv => { #20
            0 => 'Unspecified Image Color',
            1 => 'Specified Image Color',
        },
    },
    0x84e8 => { #9
        Name => 'BackgroundColorIndicator',
        PrintConv => { #20
            0 => 'Unspecified Background Color',
            1 => 'Specified Background Color',
        },
    },
    0x84e9 => 'ImageColorValue', #9
    0x84ea => 'BackgroundColorValue', #9
    0x84eb => 'PixelIntensityRange', #9
    0x84ec => 'TransparencyIndicator', #9
    0x84ed => 'ColorCharacterization', #9
    0x84ee => { #9
        Name => 'HCUsage',
        PrintConv => { #20
            0 => 'CT',
            1 => 'Line Art',
            2 => 'Trap',
        },
    },
    0x84ef => 'TrapIndicator', #17
    0x84f0 => 'CMYKEquivalent', #17
    0x8546 => { #11
        Name => 'SEMInfo',
        Notes => 'found in some scanning electron microscope images',
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0x8568 => {
        Name => 'AFCP_IPTC',
        SubDirectory => {
            # must change directory name so we don't create this directory
            DirName => 'AFCP_IPTC',
            TagTable => 'Image::ExifTool::IPTC::Main',
        },
    },
    0x85b8 => 'PixelMagicJBIGOptions', #20
    0x85d7 => 'JPLCartoIFD', #exifprobe (NC)
    0x85d8 => { #30
        Name => 'ModelTransform',
        Groups => { 2 => 'Location' },
    },
    0x8602 => { #16
        Name => 'WB_GRGBLevels',
        Notes => 'found in IFD0 of Leaf MOS images',
    },
    # 0x8603 - Leaf CatchLight color matrix (ref 16)
    0x8606 => {
        Name => 'LeafData',
        Format => 'undef',    # avoid converting huge block to string of int8u's!
        SubDirectory => {
            DirName => 'LeafIFD',
            TagTable => 'Image::ExifTool::Leaf::Main',
        },
    },
    0x8649 => { #19
        Name => 'PhotoshopSettings',
        Format => 'binary',
        WriteGroup => 'IFD0', # (only for Validate)
        SubDirectory => {
            DirName => 'Photoshop',
            TagTable => 'Image::ExifTool::Photoshop::Main',
        },
    },
    0x8769 => {
        Name => 'ExifOffset',
        Groups => { 1 => 'ExifIFD' },
        WriteGroup => 'IFD0', # (only for Validate)
        SubIFD => 2,
        SubDirectory => {
            DirName => 'ExifIFD',
            Start => '$val',
        },
    },
    0x8773 => {
        Name => 'ICC_Profile',
        WriteGroup => 'IFD0', # (only for Validate)
        SubDirectory => {
            TagTable => 'Image::ExifTool::ICC_Profile::Main',
        },
    },
    0x877f => { #20
        Name => 'TIFF_FXExtensions',
        PrintConv => { BITMASK => {
            0 => 'Resolution/Image Width',
            1 => 'N Layer Profile M',
            2 => 'Shared Data',
            3 => 'B&W JBIG2',
            4 => 'JBIG2 Profile M',
        }},
    },
    0x8780 => { #20
        Name => 'MultiProfiles',
        PrintConv => { BITMASK => {
            0 => 'Profile S',
            1 => 'Profile F',
            2 => 'Profile J',
            3 => 'Profile C',
            4 => 'Profile L',
            5 => 'Profile M',
            6 => 'Profile T',
            7 => 'Resolution/Image Width',
            8 => 'N Layer Profile M',
            9 => 'Shared Data',
            10 => 'JBIG2 Profile M',
        }},
    },
    0x8781 => { #22
        Name => 'SharedData',
        IsOffset => 1,
        # this tag is not supported for writing, so define an
        # invalid offset pair to cause a "No size tag" error to be
        # generated if we try to write a file containing this tag
        OffsetPair => -1,
    },
    0x8782 => 'T88Options', #20
    0x87ac => 'ImageLayer',
    0x87af => { #30
        Name => 'GeoTiffDirectory',
        Format => 'undef',
        Binary => 1,
        Notes => q{
            these "GeoTiff" tags may read and written as a block, but they aren't
            extracted unless specifically requested.  Byte order changes are handled
            automatically when copying between TIFF images with different byte order
        },
        Writable => 'undef',
        WriteGroup => 'IFD0',
        RawConv => '$val . GetByteOrder()', # save byte order
        # swap byte order if necessary
        RawConvInv => q{
            return $val if length $val < 2;
            my $order = substr($val, -2);
            return $val unless $order eq 'II' or $order eq 'MM';
            $val = substr($val, 0, -2);
            return $val if $order eq GetByteOrder();
            return pack('v*',unpack('n*',$val));
        },
    },
    0x87b0 => { #30
        Name => 'GeoTiffDoubleParams',
        Format => 'undef',
        Binary => 1,
        Writable => 'undef',
        WriteGroup => 'IFD0',
        RawConv => '$val . GetByteOrder()', # save byte order
        # swap byte order if necessary
        RawConvInv => q{
            return $val if length $val < 2;
            my $order = substr($val, -2);
            return $val unless $order eq 'II' or $order eq 'MM';
            $val = substr($val, 0, -2);
            return $val if $order eq GetByteOrder();
            $val =~ s/(.{4})(.{4})/$2$1/sg; # swap words
            return pack('V*',unpack('N*',$val));
        },
    },
    0x87b1 => { #30
        Name => 'GeoTiffAsciiParams',
        Writable => 'string',
        WriteGroup => 'IFD0',
        Binary => 1,
    },
    0x87be => 'JBIGOptions', #29
    0x8822 => {
        Name => 'ExposureProgram',
        Groups => { 2 => 'Camera' },
        Notes => 'the value of 9 is not standard EXIF, but is used by the Canon EOS 7D',
        Writable => 'int16u',
        PrintConv => {
            0 => 'Not Defined',
            1 => 'Manual',
            2 => 'Program AE',
            3 => 'Aperture-priority AE',
            4 => 'Shutter speed priority AE',
            5 => 'Creative (Slow speed)',
            6 => 'Action (High speed)',
            7 => 'Portrait',
            8 => 'Landscape',
            9 => 'Bulb', #25
        },
    },
    0x8824 => {
        Name => 'SpectralSensitivity',
        Groups => { 2 => 'Camera' },
        Writable => 'string',
    },
    0x8825 => {
        Name => 'GPSInfo',
        Groups => { 1 => 'GPS' },
        WriteGroup => 'IFD0', # (only for Validate)
        Flags => 'SubIFD',
        SubDirectory => {
            DirName => 'GPS',
            TagTable => 'Image::ExifTool::GPS::Main',
            Start => '$val',
            MaxSubdirs => 1,
        },
    },
    0x8827 => {
        Name => 'ISO',
        Notes => q{
            called ISOSpeedRatings by EXIF 2.2, then PhotographicSensitivity by the EXIF
            2.3 spec.
        },
        Writable => 'int16u',
        Count => -1,
        PrintConv => '$val=~s/\s+/, /g; $val',
        PrintConvInv => '$val=~tr/,//d; $val',
    },
    0x8828 => {
        Name => 'Opto-ElectricConvFactor',
        Notes => 'called OECF by the EXIF spec.',
        Binary => 1,
    },
    0x8829 => 'Interlace', #12
    0x882a => { #12
        Name => 'TimeZoneOffset',
        Writable => 'int16s',
        Count => -1, # can be 1 or 2
        Notes => q{
            1 or 2 values: 1. The time zone offset of DateTimeOriginal from GMT in
            hours, 2. If present, the time zone offset of ModifyDate
        },
    },
    0x882b => { #12
        Name => 'SelfTimerMode',
        Writable => 'int16u',
    },
    0x8830 => { #24
        Name => 'SensitivityType',
        Notes => 'applies to EXIF:ISO tag',
        Writable => 'int16u',
        PrintConv => {
            0 => 'Unknown',
            1 => 'Standard Output Sensitivity',
            2 => 'Recommended Exposure Index',
            3 => 'ISO Speed',
            4 => 'Standard Output Sensitivity and Recommended Exposure Index',
            5 => 'Standard Output Sensitivity and ISO Speed',
            6 => 'Recommended Exposure Index and ISO Speed',
            7 => 'Standard Output Sensitivity, Recommended Exposure Index and ISO Speed',
        },
    },
    0x8831 => { #24
        Name => 'StandardOutputSensitivity',
        Writable => 'int32u',
    },
    0x8832 => { #24
        Name => 'RecommendedExposureIndex',
        Writable => 'int32u',
    },
    0x8833 => { #24
        Name => 'ISOSpeed',
        Writable => 'int32u',
    },
    0x8834 => { #24
        Name => 'ISOSpeedLatitudeyyy',
        Description => 'ISO Speed Latitude yyy',
        Writable => 'int32u',
    },
    0x8835 => { #24
        Name => 'ISOSpeedLatitudezzz',
        Description => 'ISO Speed Latitude zzz',
        Writable => 'int32u',
    },
    0x885c => 'FaxRecvParams', #9
    0x885d => 'FaxSubAddress', #9
    0x885e => 'FaxRecvTime', #9
    0x8871 => 'FedexEDR', #exifprobe (NC)
    0x888a => { #PH
        Name => 'LeafSubIFD',
        Format => 'int32u',     # Leaf incorrectly uses 'undef' format!
        Groups => { 1 => 'LeafSubIFD' },
        Flags => 'SubIFD',
        SubDirectory => {
            TagTable => 'Image::ExifTool::Leaf::SubIFD',
            Start => '$val',
        },
    },
  # 0x89ab - seen "11 100 130 16 0 0 0 0" in IFD0 of TIFF image from IR scanner (forum8470)
    0x9000 => {
        Name => 'ExifVersion',
        Writable => 'undef',
        Mandatory => 1,
        RawConv => '$val=~s/\0+$//; $val',  # (some idiots add null terminators)
        PrintConvInv => '$val=~tr/.//d; $val=~/^\d{4}$/ ? $val : undef',
    },
    0x9003 => {
        Name => 'DateTimeOriginal',
        Description => 'Date/Time Original',
        Groups => { 2 => 'Time' },
        Notes => 'date/time when original image was taken',
        Writable => 'string',
        Shift => 'Time',
        Validate => 'ValidateExifDate($val)',
        PrintConv => '$self->ConvertDateTime($val)',
        PrintConvInv => '$self->InverseDateTime($val,0)',
    },
    0x9004 => {
        Name => 'CreateDate',
        Groups => { 2 => 'Time' },
        Notes => 'called DateTimeDigitized by the EXIF spec.',
        Writable => 'string',
        Shift => 'Time',
        Validate => 'ValidateExifDate($val)',
        PrintConv => '$self->ConvertDateTime($val)',
        PrintConvInv => '$self->InverseDateTime($val,0)',
    },
    0x9009 => { # undef[44] (or undef[11]) written by Google Plus uploader - PH
        Name => 'GooglePlusUploadCode',
        Format => 'int8u',
        Writable => 'undef',
        Count => -1,
    },
    0x9010 => {
        Name => 'OffsetTime',
        Groups => { 2 => 'Time' },
        Notes => 'time zone for ModifyDate',
        Writable => 'string',
        PrintConvInv => q{
            return "+00:00" if $val =~ /\d{2}Z$/;
            return sprintf("%s%.2d:%.2d",$1,$2,$3) if $val =~ /([-+])(\d{1,2}):(\d{2})/;
            return undef;
        },
    },
    0x9011 => {
        Name => 'OffsetTimeOriginal',
        Groups => { 2 => 'Time' },
        Notes => 'time zone for DateTimeOriginal',
        Writable => 'string',
        PrintConvInv => q{
            return "+00:00" if $val =~ /\d{2}Z$/;
            return sprintf("%s%.2d:%.2d",$1,$2,$3) if $val =~ /([-+])(\d{1,2}):(\d{2})/;
            return undef;
        },
    },
    0x9012 => {
        Name => 'OffsetTimeDigitized',
        Groups => { 2 => 'Time' },
        Notes => 'time zone for CreateDate',
        Writable => 'string',
        PrintConvInv => q{
            return "+00:00" if $val =~ /\d{2}Z$/;
            return sprintf("%s%.2d:%.2d",$1,$2,$3) if $val =~ /([-+])(\d{1,2}):(\d{2})/;
            return undef;
        },
    },
    0x9101 => {
        Name => 'ComponentsConfiguration',
        Format => 'int8u',
        Protected => 1,
        Writable => 'undef',
        Count => 4,
        Mandatory => 1,
        ValueConvInv => '$val=~tr/,//d; $val',  # (so we can copy from XMP with -n)
        PrintConvColumns => 2,
        PrintConv => {
            0 => '-',
            1 => 'Y',
            2 => 'Cb',
            3 => 'Cr',
            4 => 'R',
            5 => 'G',
            6 => 'B',
            OTHER => sub {
                my ($val, $inv, $conv) = @_;
                my @a = split /,?\s+/, $val;
                if ($inv) {
                    my %invConv;
                    $invConv{lc $$conv{$_}} = $_ foreach keys %$conv;
                    # strings like "YCbCr" and "RGB" still work for writing
                    @a = $a[0] =~ /(Y|Cb|Cr|R|G|B)/g if @a == 1;
                    foreach (@a) {
                        $_ = $invConv{lc $_};
                        return undef unless defined $_;
                    }
                    push @a, 0 while @a < 4;
                } else {
                    foreach (@a) {
                        $_ = $$conv{$_} || "Err ($_)";
                    }
                }
                return join ', ', @a;
            },
        },
    },
    0x9102 => {
        Name => 'CompressedBitsPerPixel',
        Protected => 1,
        Writable => 'rational64u',
    },
    # 0x9103 - int16u: 1 (found in Pentax XG-1 samples)
    0x9201 => {
        Name => 'ShutterSpeedValue',
        Notes => 'displayed in seconds, but stored as an APEX value',
        Format => 'rational64s', # Leica M8 patch (incorrectly written as rational64u)
        Writable => 'rational64s',
        ValueConv => 'abs($val)<100 ? 2**(-$val) : 0',
        ValueConvInv => '$val>0 ? -log($val)/log(2) : -100',
        PrintConv => 'Image::ExifTool::Exif::PrintExposureTime($val)',
        PrintConvInv => 'Image::ExifTool::Exif::ConvertFraction($val)',
    },
    0x9202 => {
        Name => 'ApertureValue',
        Notes => 'displayed as an F number, but stored as an APEX value',
        Writable => 'rational64u',
        ValueConv => '2 ** ($val / 2)',
        ValueConvInv => '$val>0 ? 2*log($val)/log(2) : 0',
        PrintConv => 'sprintf("%.1f",$val)',
        PrintConvInv => '$val',
    },
    # Wikipedia: BrightnessValue = Bv = Av + Tv - Sv
    # ExifTool:  LightValue = LV = Av + Tv - Sv + 5 (5 is the Sv for ISO 100 in Exif usage)
    0x9203 => {
        Name => 'BrightnessValue',
        Writable => 'rational64s',
    },
    0x9204 => {
        Name => 'ExposureCompensation',
        Format => 'rational64s', # Leica M8 patch (incorrectly written as rational64u)
        Notes => 'called ExposureBiasValue by the EXIF spec.',
        Writable => 'rational64s',
        PrintConv => 'Image::ExifTool::Exif::PrintFraction($val)',
        PrintConvInv => '$val',
    },
    0x9205 => {
        Name => 'MaxApertureValue',
        Notes => 'displayed as an F number, but stored as an APEX value',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
        ValueConv => '2 ** ($val / 2)',
        ValueConvInv => '$val>0 ? 2*log($val)/log(2) : 0',
        PrintConv => 'sprintf("%.1f",$val)',
        PrintConvInv => '$val',
    },
    0x9206 => {
        Name => 'SubjectDistance',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
        PrintConv => '$val =~ /^(inf|undef)$/ ? $val : "${val} m"',
        PrintConvInv => '$val=~s/\s*m$//;$val',
    },
    0x9207 => {
        Name => 'MeteringMode',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            0 => 'Unknown',
            1 => 'Average',
            2 => 'Center-weighted average',
            3 => 'Spot',
            4 => 'Multi-spot',
            5 => 'Multi-segment',
            6 => 'Partial',
            255 => 'Other',
        },
    },
    0x9208 => {
        Name => 'LightSource',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        SeparateTable => 'LightSource',
        PrintConv => \%lightSource,
    },
    0x9209 => {
        Name => 'Flash',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        Flags => 'PrintHex',
        SeparateTable => 'Flash',
        PrintConv => \%flash,
    },
    0x920a => {
        Name => 'FocalLength',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
        PrintConv => 'sprintf("%.1f mm",$val)',
        PrintConvInv => '$val=~s/\s*mm$//;$val',
    },
    # Note: tags 0x920b-0x9217 are duplicates of 0xa20b-0xa217
    # (The EXIF standard uses 0xa2xx, but you'll find both in images)
    0x920b => { #12
        Name => 'FlashEnergy',
        Groups => { 2 => 'Camera' },
    },
    0x920c => 'SpatialFrequencyResponse', #12 (not in Fuji images - PH)
    0x920d => 'Noise', #12
    0x920e => 'FocalPlaneXResolution', #12
    0x920f => 'FocalPlaneYResolution', #12
    0x9210 => { #12
        Name => 'FocalPlaneResolutionUnit',
        Groups => { 2 => 'Camera' },
        PrintConv => {
            1 => 'None',
            2 => 'inches',
            3 => 'cm',
            4 => 'mm',
            5 => 'um',
        },
    },
    0x9211 => { #12
        Name => 'ImageNumber',
        Writable => 'int32u',
    },
    0x9212 => { #12
        Name => 'SecurityClassification',
        Writable => 'string',
        PrintConv => {
            T => 'Top Secret',
            S => 'Secret',
            C => 'Confidential',
            R => 'Restricted',
            U => 'Unclassified',
        },
    },
    0x9213 => { #12
        Name => 'ImageHistory',
        Writable => 'string',
    },
    0x9214 => {
        Name => 'SubjectArea',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        Count => -1, # 2, 3 or 4 values
    },
    0x9215 => 'ExposureIndex', #12
    0x9216 => 'TIFF-EPStandardID', #12
    0x9217 => { #12
        Name => 'SensingMethod',
        Groups => { 2 => 'Camera' },
        PrintConv => {
            # (values 1 and 6 are not used by corresponding EXIF tag 0xa217)
            1 => 'Monochrome area',
            2 => 'One-chip color area',
            3 => 'Two-chip color area',
            4 => 'Three-chip color area',
            5 => 'Color sequential area',
            6 => 'Monochrome linear',
            7 => 'Trilinear',
            8 => 'Color sequential linear',
        },
    },
    0x923a => 'CIP3DataFile', #20
    0x923b => 'CIP3Sheet', #20
    0x923c => 'CIP3Side', #20
    0x923f => 'StoNits', #9
    # handle maker notes as a conditional list
    0x927c => \@Image::ExifTool::MakerNotes::Main,
    0x9286 => {
        Name => 'UserComment',
        # I have seen other applications write it incorrectly as 'string' or 'int8u'
        Format => 'undef',
        Writable => 'undef',
        RawConv => 'Image::ExifTool::Exif::ConvertExifText($self,$val,1,$tag)',
        #  (starts with "ASCII\0\0\0", "UNICODE\0", "JIS\0\0\0\0\0" or "\0\0\0\0\0\0\0\0")
        RawConvInv => 'Image::ExifTool::Exif::EncodeExifText($self,$val)',
        # SHOULD ADD SPECIAL LOGIC TO ALLOW CONDITIONAL OVERWRITE OF
        # "UNKNOWN" VALUES FILLED WITH SPACES
    },
    0x9290 => {
        Name => 'SubSecTime',
        Groups => { 2 => 'Time' },
        Notes => 'fractional seconds for ModifyDate',
        Writable => 'string',
        ValueConv => '$val=~s/ +$//; $val', # trim trailing blanks
        # extract fractional seconds from a full date/time value
        ValueConvInv => '$val=~/^(\d+)\s*$/ ? $1 : ($val=~/\.(\d+)/ ? $1 : undef)',
    },
    0x9291 => {
        Name => 'SubSecTimeOriginal',
        Groups => { 2 => 'Time' },
        Notes => 'fractional seconds for DateTimeOriginal',
        Writable => 'string',
        ValueConv => '$val=~s/ +$//; $val', # trim trailing blanks
        ValueConvInv => '$val=~/^(\d+)\s*$/ ? $1 : ($val=~/\.(\d+)/ ? $1 : undef)',
    },
    0x9292 => {
        Name => 'SubSecTimeDigitized',
        Groups => { 2 => 'Time' },
        Notes => 'fractional seconds for CreateDate',
        Writable => 'string',
        ValueConv => '$val=~s/ +$//; $val', # trim trailing blanks
        ValueConvInv => '$val=~/^(\d+)\s*$/ ? $1 : ($val=~/\.(\d+)/ ? $1 : undef)',
    },
    # The following 3 tags are found in MSOffice TIFF images
    # References:
    # http://social.msdn.microsoft.com/Forums/en-US/os_standocs/thread/03086d55-294a-49d5-967a-5303d34c40f8/
    # http://blogs.msdn.com/openspecification/archive/2009/12/08/details-of-three-tiff-tag-extensions-that-microsoft-office-document-imaging-modi-software-may-write-into-the-tiff-files-it-generates.aspx
    # http://www.microsoft.com/downloads/details.aspx?FamilyID=0dbc435d-3544-4f4b-9092-2f2643d64a39&displaylang=en#filelist
    0x932f => 'MSDocumentText',
    0x9330 => {
        Name => 'MSPropertySetStorage',
        Binary => 1,
    },
    0x9331 => {
        Name => 'MSDocumentTextPosition',
        Binary => 1, # (just in case -- don't know what format this is)
    },
    0x935c => { #3/19
        Name => 'ImageSourceData', # (writable directory!)
        Writable => 'undef',
        WriteGroup => 'IFD0',
        SubDirectory => { TagTable => 'Image::ExifTool::Photoshop::DocumentData' },
        Binary => 1,
        Protected => 1, # (because this can be hundreds of megabytes)
    },
    0x9400 => {
        Name => 'AmbientTemperature',
        Notes => 'ambient temperature in degrees C, called Temperature by the EXIF spec.',
        Writable => 'rational64s',
        PrintConv => '"$val C"',
        PrintConvInv => '$val=~s/ ?C//; $val',
    },
    0x9401 => {
        Name => 'Humidity',
        Notes => 'ambient relative humidity in percent',
        Writable => 'rational64u',
    },
    0x9402 => {
        Name => 'Pressure',
        Notes => 'air pressure in hPa or mbar',
        Writable => 'rational64u',
    },
    0x9403 => {
        Name => 'WaterDepth',
        Notes => 'depth under water in metres, negative for above water',
        Writable => 'rational64s',
    },
    0x9404 => {
        Name => 'Acceleration',
        Notes => 'directionless camera acceleration in units of mGal, or 10-5 m/s2',
        Writable => 'rational64u',
    },
    0x9405 => {
        Name => 'CameraElevationAngle',
        Writable => 'rational64s',
    },
    0x9c9b => {
        Name => 'XPTitle',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Notes => q{
            tags 0x9c9b-0x9c9f are used by Windows Explorer; special characters
            in these values are converted to UTF-8 by default, or Windows Latin1
            with the -L option.  XPTitle is ignored by Windows Explorer if
            ImageDescription exists
        },
        ValueConv => '$self->Decode($val,"UCS2","II")',
        ValueConvInv => '$self->Encode($val,"UCS2","II") . "\0\0"',
    },
    0x9c9c => {
        Name => 'XPComment',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        ValueConv => '$self->Decode($val,"UCS2","II")',
        ValueConvInv => '$self->Encode($val,"UCS2","II") . "\0\0"',
    },
    0x9c9d => {
        Name => 'XPAuthor',
        Groups => { 2 => 'Author' },
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Notes => 'ignored by Windows Explorer if Artist exists',
        ValueConv => '$self->Decode($val,"UCS2","II")',
        ValueConvInv => '$self->Encode($val,"UCS2","II") . "\0\0"',
    },
    0x9c9e => {
        Name => 'XPKeywords',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        ValueConv => '$self->Decode($val,"UCS2","II")',
        ValueConvInv => '$self->Encode($val,"UCS2","II") . "\0\0"',
    },
    0x9c9f => {
        Name => 'XPSubject',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        ValueConv => '$self->Decode($val,"UCS2","II")',
        ValueConvInv => '$self->Encode($val,"UCS2","II") . "\0\0"',
    },
    0xa000 => {
        Name => 'FlashpixVersion',
        Writable => 'undef',
        Mandatory => 1,
        RawConv => '$val=~s/\0+$//; $val',  # (some idiots add null terminators)
        PrintConvInv => '$val=~tr/.//d; $val=~/^\d{4}$/ ? $val : undef',
    },
    0xa001 => {
        Name => 'ColorSpace',
        Notes => q{
            the value of 0x2 is not standard EXIF.  Instead, an Adobe RGB image is
            indicated by "Uncalibrated" with an InteropIndex of "R03".  The values
            0xfffd and 0xfffe are also non-standard, and are used by some Sony cameras
        },
        Writable => 'int16u',
        Mandatory => 1,
        PrintHex => 1,
        PrintConv => {
            1 => 'sRGB',
            2 => 'Adobe RGB',
            0xffff => 'Uncalibrated',
            # Sony uses these definitions: (ref JD)
            # 0xffff => 'Adobe RGB', (conflicts with Uncalibrated)
            0xfffe => 'ICC Profile',
            0xfffd => 'Wide Gamut RGB',
        },
    },
    0xa002 => {
        Name => 'ExifImageWidth',
        Notes => 'called PixelXDimension by the EXIF spec.',
        Writable => 'int16u',
        Mandatory => 1,
    },
    0xa003 => {
        Name => 'ExifImageHeight',
        Notes => 'called PixelYDimension by the EXIF spec.',
        Writable => 'int16u',
        Mandatory => 1,
    },
    0xa004 => {
        Name => 'RelatedSoundFile',
        Writable => 'string',
    },
    0xa005 => {
        Name => 'InteropOffset',
        Groups => { 1 => 'InteropIFD' },
        Flags => 'SubIFD',
        Description => 'Interoperability Offset',
        SubDirectory => {
            DirName => 'InteropIFD',
            Start => '$val',
            MaxSubdirs => 1,
        },
    },
    # the following 4 tags found in SubIFD1 of some Samsung SRW images
    0xa010 => {
        Name => 'SamsungRawPointersOffset',
        IsOffset => 1,
        OffsetPair => 0xa011,  # point to associated byte count
    },
    0xa011 => {
        Name => 'SamsungRawPointersLength',
        OffsetPair => 0xa010,  # point to associated offset
    },
    0xa101 => {
        Name => 'SamsungRawByteOrder',
        Format => 'undef',
        # this is written incorrectly as string[1], but is "\0\0MM" or "II\0\0"
        FixedSize => 4,
        Count => 1,
    },
    0xa102 => {
        Name => 'SamsungRawUnknown',
        Unknown => 1,
    },
    0xa20b => {
        Name => 'FlashEnergy',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
    },
    0xa20c => {
        Name => 'SpatialFrequencyResponse',
        PrintConv => 'Image::ExifTool::Exif::PrintSFR($val)',
    },
    0xa20d => 'Noise',
    0xa20e => {
        Name => 'FocalPlaneXResolution',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
    },
    0xa20f => {
        Name => 'FocalPlaneYResolution',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
    },
    0xa210 => {
        Name => 'FocalPlaneResolutionUnit',
        Groups => { 2 => 'Camera' },
        Notes => 'values 1, 4 and 5 are not standard EXIF',
        Writable => 'int16u',
        PrintConv => {
            1 => 'None', # (not standard EXIF)
            2 => 'inches',
            3 => 'cm',
            4 => 'mm',   # (not standard EXIF)
            5 => 'um',   # (not standard EXIF)
        },
    },
    0xa211 => 'ImageNumber',
    0xa212 => 'SecurityClassification',
    0xa213 => 'ImageHistory',
    0xa214 => {
        Name => 'SubjectLocation',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        Count => 2,
    },
    0xa215 => { Name => 'ExposureIndex', Writable => 'rational64u' },
    0xa216 => 'TIFF-EPStandardID',
    0xa217 => {
        Name => 'SensingMethod',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            1 => 'Not defined',
            2 => 'One-chip color area',
            3 => 'Two-chip color area',
            4 => 'Three-chip color area',
            5 => 'Color sequential area',
            7 => 'Trilinear',
            8 => 'Color sequential linear',
        },
    },
    0xa300 => {
        Name => 'FileSource',
        Writable => 'undef',
        ValueConvInv => '($val=~/^\d+$/ and $val < 256) ? chr($val) : $val',
        PrintConv => {
            1 => 'Film Scanner',
            2 => 'Reflection Print Scanner',
            3 => 'Digital Camera',
            # handle the case where Sigma incorrectly gives this tag a count of 4
            "\3\0\0\0" => 'Sigma Digital Camera',
        },
    },
    0xa301 => {
        Name => 'SceneType',
        Writable => 'undef',
        ValueConvInv => 'chr($val)',
        PrintConv => {
            1 => 'Directly photographed',
        },
    },
    0xa302 => {
        Name => 'CFAPattern',
        Writable => 'undef',
        RawConv => 'Image::ExifTool::Exif::DecodeCFAPattern($self, $val)',
        RawConvInv => q{
            my @a = split ' ', $val;
            return $val if @a <= 2; # also accept binary data for backward compatibility
            return pack(GetByteOrder() eq 'II' ? 'v2C*' : 'n2C*', @a);
        },
        PrintConv => 'Image::ExifTool::Exif::PrintCFAPattern($val)',
        PrintConvInv => 'Image::ExifTool::Exif::GetCFAPattern($val)',
    },
    0xa401 => {
        Name => 'CustomRendered',
        Writable => 'int16u',
        Notes => q{
            only 0 and 1 are standard EXIF, but other values are used by Apple iOS
            devices
        },
        PrintConv => {
            0 => 'Normal',
            1 => 'Custom',
            # 2 - also seen (Apple iOS)
            3 => 'HDR',      # non-standard (Apple iOS)
            # 4 - also seen (Apple iOS) - normal image from iOS Camera app (ref http://regex.info/blog/lightroom-goodies/metadata-presets)
            6 => 'Panorama', # non-standard (Apple iOS, horizontal or vertical)
            # 7 - also seen (Apple iOS)
            8 => 'Portrait', # non-standard (Apple iOS, blurred background)
            # 9 - also seen (Apple iOS) (HDR Portrait?)
        },
    },
    0xa402 => {
        Name => 'ExposureMode',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            0 => 'Auto',
            1 => 'Manual',
            2 => 'Auto bracket',
            # have seen 3 from Samsung EX1, NX30, NX200 - PH
        },
    },
    0xa403 => {
        Name => 'WhiteBalance',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        # set Priority to zero to keep this WhiteBalance from overriding the
        # MakerNotes WhiteBalance, since the MakerNotes WhiteBalance and is more
        # accurate and contains more information (if it exists)
        Priority => 0,
        PrintConv => {
            0 => 'Auto',
            1 => 'Manual',
        },
    },
    0xa404 => {
        Name => 'DigitalZoomRatio',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
    },
    0xa405 => {
        Name => 'FocalLengthIn35mmFormat',
        Notes => 'called FocalLengthIn35mmFilm by the EXIF spec.',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => '"$val mm"',
        PrintConvInv => '$val=~s/\s*mm$//;$val',
    },
    0xa406 => {
        Name => 'SceneCaptureType',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            0 => 'Standard',
            1 => 'Landscape',
            2 => 'Portrait',
            3 => 'Night',
            # 4 - HDR (Samsung GT-I9300)
        },
    },
    0xa407 => {
        Name => 'GainControl',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            0 => 'None',
            1 => 'Low gain up',
            2 => 'High gain up',
            3 => 'Low gain down',
            4 => 'High gain down',
        },
    },
    0xa408 => {
        Name => 'Contrast',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            0 => 'Normal',
            1 => 'Low',
            2 => 'High',
        },
        PrintConvInv => 'Image::ExifTool::Exif::ConvertParameter($val)',
    },
    0xa409 => {
        Name => 'Saturation',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            0 => 'Normal',
            1 => 'Low',
            2 => 'High',
        },
        PrintConvInv => 'Image::ExifTool::Exif::ConvertParameter($val)',
    },
    0xa40a => {
        Name => 'Sharpness',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            0 => 'Normal',
            1 => 'Soft',
            2 => 'Hard',
        },
        PrintConvInv => 'Image::ExifTool::Exif::ConvertParameter($val)',
    },
    0xa40b => {
        Name => 'DeviceSettingDescription',
        Groups => { 2 => 'Camera' },
        Binary => 1,
    },
    0xa40c => {
        Name => 'SubjectDistanceRange',
        Groups => { 2 => 'Camera' },
        Writable => 'int16u',
        PrintConv => {
            0 => 'Unknown',
            1 => 'Macro',
            2 => 'Close',
            3 => 'Distant',
        },
    },
    # 0xa40d - int16u: 0 (GE E1486 TW)
    # 0xa40e - int16u: 1 (GE E1486 TW)
    0xa420 => { Name => 'ImageUniqueID', Writable => 'string' },
    0xa430 => { #24
        Name => 'OwnerName',
        Notes => 'called CameraOwnerName by the EXIF spec.',
        Writable => 'string',
    },
    0xa431 => { #24
        Name => 'SerialNumber',
        Notes => 'called BodySerialNumber by the EXIF spec.',
        Writable => 'string',
    },
    0xa432 => { #24
        Name => 'LensInfo',
        Notes => q{
            4 rational values giving focal and aperture ranges, called LensSpecification
            by the EXIF spec.
        },
        Writable => 'rational64u',
        Count => 4,
        # convert to the form "12-20mm f/3.8-4.5" or "50mm f/1.4"
        PrintConv => \&Image::ExifTool::Exif::PrintLensInfo,
        PrintConvInv => \&ConvertLensInfo,
    },
    0xa433 => { Name => 'LensMake',         Writable => 'string' }, #24
    0xa434 => { Name => 'LensModel',        Writable => 'string' }, #24
    0xa435 => { Name => 'LensSerialNumber', Writable => 'string' }, #24
    0xa480 => 'GDALMetadata', #3
    0xa481 => 'GDALNoData', #3
    0xa500 => { Name => 'Gamma', Writable => 'rational64u' },
    0xafc0 => 'ExpandSoftware', #JD (Opanda)
    0xafc1 => 'ExpandLens', #JD (Opanda)
    0xafc2 => 'ExpandFilm', #JD (Opanda)
    0xafc3 => 'ExpandFilterLens', #JD (Opanda)
    0xafc4 => 'ExpandScanner', #JD (Opanda)
    0xafc5 => 'ExpandFlashLamp', #JD (Opanda)
#
# Windows Media Photo / HD Photo (WDP/HDP) tags
#
    0xbc01 => { #13
        Name => 'PixelFormat',
        PrintHex => 1,
        Format => 'undef',
        Notes => q{
            tags 0xbc** are used in Windows HD Photo (HDP and WDP) images. The actual
            PixelFormat values are 16-byte GUID's but the leading 15 bytes,
            '6fddc324-4e03-4bfe-b1853-d77768dc9', have been removed below to avoid
            unnecessary clutter
        },
        ValueConv => q{
            require Image::ExifTool::ASF;
            $val = Image::ExifTool::ASF::GetGUID($val);
            # GUID's are too long, so remove redundant information
            $val =~ s/^6fddc324-4e03-4bfe-b185-3d77768dc9//i and $val = hex($val);
            return $val;
        },
        PrintConv => {
            0x0d => '24-bit RGB',
            0x0c => '24-bit BGR',
            0x0e => '32-bit BGR',
            0x15 => '48-bit RGB',
            0x12 => '48-bit RGB Fixed Point',
            0x3b => '48-bit RGB Half',
            0x18 => '96-bit RGB Fixed Point',
            0x1b => '128-bit RGB Float',
            0x0f => '32-bit BGRA',
            0x16 => '64-bit RGBA',
            0x1d => '64-bit RGBA Fixed Point',
            0x3a => '64-bit RGBA Half',
            0x1e => '128-bit RGBA Fixed Point',
            0x19 => '128-bit RGBA Float',
            0x10 => '32-bit PBGRA',
            0x17 => '64-bit PRGBA',
            0x1a => '128-bit PRGBA Float',
            0x1c => '32-bit CMYK',
            0x2c => '40-bit CMYK Alpha',
            0x1f => '64-bit CMYK',
            0x2d => '80-bit CMYK Alpha',
            0x20 => '24-bit 3 Channels',
            0x21 => '32-bit 4 Channels',
            0x22 => '40-bit 5 Channels',
            0x23 => '48-bit 6 Channels',
            0x24 => '56-bit 7 Channels',
            0x25 => '64-bit 8 Channels',
            0x2e => '32-bit 3 Channels Alpha',
            0x2f => '40-bit 4 Channels Alpha',
            0x30 => '48-bit 5 Channels Alpha',
            0x31 => '56-bit 6 Channels Alpha',
            0x32 => '64-bit 7 Channels Alpha',
            0x33 => '72-bit 8 Channels Alpha',
            0x26 => '48-bit 3 Channels',
            0x27 => '64-bit 4 Channels',
            0x28 => '80-bit 5 Channels',
            0x29 => '96-bit 6 Channels',
            0x2a => '112-bit 7 Channels',
            0x2b => '128-bit 8 Channels',
            0x34 => '64-bit 3 Channels Alpha',
            0x35 => '80-bit 4 Channels Alpha',
            0x36 => '96-bit 5 Channels Alpha',
            0x37 => '112-bit 6 Channels Alpha',
            0x38 => '128-bit 7 Channels Alpha',
            0x39 => '144-bit 8 Channels Alpha',
            0x08 => '8-bit Gray',
            0x0b => '16-bit Gray',
            0x13 => '16-bit Gray Fixed Point',
            0x3e => '16-bit Gray Half',
            0x3f => '32-bit Gray Fixed Point',
            0x11 => '32-bit Gray Float',
            0x05 => 'Black & White',
            0x09 => '16-bit BGR555',
            0x0a => '16-bit BGR565',
            0x13 => '32-bit BGR101010',
            0x3d => '32-bit RGBE',
        },
    },
    0xbc02 => { #13
        Name => 'Transformation',
        PrintConv => {
            0 => 'Horizontal (normal)',
            1 => 'Mirror vertical',
            2 => 'Mirror horizontal',
            3 => 'Rotate 180',
            4 => 'Rotate 90 CW',
            5 => 'Mirror horizontal and rotate 90 CW',
            6 => 'Mirror horizontal and rotate 270 CW',
            7 => 'Rotate 270 CW',
        },
    },
    0xbc03 => { #13
        Name => 'Uncompressed',
        PrintConv => { 0 => 'No', 1 => 'Yes' },
    },
    0xbc04 => { #13
        Name => 'ImageType',
        PrintConv => { BITMASK => {
            0 => 'Preview',
            1 => 'Page',
        } },
    },
    0xbc80 => 'ImageWidth', #13
    0xbc81 => 'ImageHeight', #13
    0xbc82 => 'WidthResolution', #13
    0xbc83 => 'HeightResolution', #13
    0xbcc0 => { #13
        Name => 'ImageOffset',
        IsOffset => 1,
        OffsetPair => 0xbcc1,  # point to associated byte count
    },
    0xbcc1 => { #13
        Name => 'ImageByteCount',
        OffsetPair => 0xbcc0,  # point to associated offset
    },
    0xbcc2 => { #13
        Name => 'AlphaOffset',
        IsOffset => 1,
        OffsetPair => 0xbcc3,  # point to associated byte count
    },
    0xbcc3 => { #13
        Name => 'AlphaByteCount',
        OffsetPair => 0xbcc2,  # point to associated offset
    },
    0xbcc4 => { #13
        Name => 'ImageDataDiscard',
        PrintConv => {
            0 => 'Full Resolution',
            1 => 'Flexbits Discarded',
            2 => 'HighPass Frequency Data Discarded',
            3 => 'Highpass and LowPass Frequency Data Discarded',
        },
    },
    0xbcc5 => { #13
        Name => 'AlphaDataDiscard',
        PrintConv => {
            0 => 'Full Resolution',
            1 => 'Flexbits Discarded',
            2 => 'HighPass Frequency Data Discarded',
            3 => 'Highpass and LowPass Frequency Data Discarded',
        },
    },
#
    0xc427 => 'OceScanjobDesc', #3
    0xc428 => 'OceApplicationSelector', #3
    0xc429 => 'OceIDNumber', #3
    0xc42a => 'OceImageLogic', #3
    0xc44f => { Name => 'Annotations', Binary => 1 }, #7/19
    0xc4a5 => {
        Name => 'PrintIM', # (writable directory!)
        # must set Writable here so this tag will be saved with MakerNotes option
        Writable => 'undef',
        WriteGroup => 'IFD0',
        Binary => 1,
        # (don't make Binary/Protected because we can't copy individual PrintIM tags anyway)
        Description => 'Print Image Matching',
        SubDirectory => {
            TagTable => 'Image::ExifTool::PrintIM::Main',
        },
        PrintConvInv => '$val =~ /^PrintIM/ ? $val : undef',    # quick validation
    },
    0xc573 => { #PH
        Name => 'OriginalFileName',
        Notes => 'used by some obscure software', # (possibly Swizzy Photosmacker?)
        # (it is a 'string', but obscure, so don't make it writable)
    },
    0xc580 => { #20
        Name => 'USPTOOriginalContentType',
        PrintConv => {
            0 => 'Text or Drawing',
            1 => 'Grayscale',
            2 => 'Color',
        },
    },
    # 0xc5d8 - found in CR2 images
    # 0xc5d9 - found in CR2 images
    0xc5e0 => { #forum8153 (CR2 images)
        Name => 'CR2CFAPattern',
        ValueConv => {
            1 => '0 1 1 2',
            2 => '2 1 1 0',
            3 => '1 2 0 1',
            4 => '1 0 2 1',
        },
        PrintConv => {
            '0 1 1 2' => '[Red,Green][Green,Blue]',
            '2 1 1 0' => '[Blue,Green][Green,Red]',
            '1 2 0 1' => '[Green,Blue][Red,Green]',
            '1 0 2 1' => '[Green,Red][Blue,Green]',
        },
    },
#
# DNG tags 0xc6XX and 0xc7XX (ref 2 unless otherwise stated)
#
    0xc612 => {
        Name => 'DNGVersion',
        Notes => q{
            tags 0xc612-0xc7b5 are defined by the DNG specification unless otherwise
            noted.  See L<https://helpx.adobe.com/photoshop/digital-negative.html> for
            the specification
        },
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Count => 4,
        Protected => 1, # (confuses Apple Preview if written to a TIFF image)
        DataMember => 'DNGVersion',
        RawConv => '$$self{DNGVersion} = $val',
        PrintConv => '$val =~ tr/ /./; $val',
        PrintConvInv => '$val =~ tr/./ /; $val',
    },
    0xc613 => {
        Name => 'DNGBackwardVersion',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Count => 4,
        Protected => 1,
        PrintConv => '$val =~ tr/ /./; $val',
        PrintConvInv => '$val =~ tr/./ /; $val',
    },
    0xc614 => {
        Name => 'UniqueCameraModel',
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0xc615 => {
        Name => 'LocalizedCameraModel',
        WriteGroup => 'IFD0',
        %utf8StringConv,
        PrintConv => '$self->Printable($val, 0)',
        PrintConvInv => '$val',
    },
    0xc616 => {
        Name => 'CFAPlaneColor',
        WriteGroup => 'SubIFD', # (only for Validate)
        PrintConv => q{
            my @cols = qw(Red Green Blue Cyan Magenta Yellow White);
            my @vals = map { $cols[$_] || "Unknown($_)" } split(' ', $val);
            return join(',', @vals);
        },
    },
    0xc617 => {
        Name => 'CFALayout',
        WriteGroup => 'SubIFD', # (only for Validate)
        PrintConv => {
            1 => 'Rectangular',
            2 => 'Even columns offset down 1/2 row',
            3 => 'Even columns offset up 1/2 row',
            4 => 'Even rows offset right 1/2 column',
            5 => 'Even rows offset left 1/2 column',
            # the following are new for DNG 1.3:
            6 => 'Even rows offset up by 1/2 row, even columns offset left by 1/2 column',
            7 => 'Even rows offset up by 1/2 row, even columns offset right by 1/2 column',
            8 => 'Even rows offset down by 1/2 row, even columns offset left by 1/2 column',
            9 => 'Even rows offset down by 1/2 row, even columns offset right by 1/2 column',
        },
    },
    0xc618 => {
        Name => 'LinearizationTable',
        Writable => 'int16u',
        WriteGroup => 'SubIFD',
        Count => -1,
        Protected => 1,
        Binary => 1,
    },
    0xc619 => {
        Name => 'BlackLevelRepeatDim',
        Writable => 'int16u',
        WriteGroup => 'SubIFD',
        Count => 2,
        Protected => 1,
    },
    0xc61a => {
        Name => 'BlackLevel',
        Writable => 'rational64u',
        WriteGroup => 'SubIFD',
        Count => -1,
        Protected => 1,
    },
    0xc61b => {
        Name => 'BlackLevelDeltaH',
        %longBin,
        Writable => 'rational64s',
        WriteGroup => 'SubIFD',
        Count => -1,
        Protected => 1,
    },
    0xc61c => {
        Name => 'BlackLevelDeltaV',
        %longBin,
        Writable => 'rational64s',
        WriteGroup => 'SubIFD',
        Count => -1,
        Protected => 1,
    },
    0xc61d => {
        Name => 'WhiteLevel',
        Writable => 'int32u',
        WriteGroup => 'SubIFD',
        Count => -1,
        Protected => 1,
    },
    0xc61e => {
        Name => 'DefaultScale',
        Writable => 'rational64u',
        WriteGroup => 'SubIFD',
        Count => 2,
        Protected => 1,
    },
    0xc61f => {
        Name => 'DefaultCropOrigin',
        Writable => 'int32u',
        WriteGroup => 'SubIFD',
        Count => 2,
        Protected => 1,
    },
    0xc620 => {
        Name => 'DefaultCropSize',
        Writable => 'int32u',
        WriteGroup => 'SubIFD',
        Count => 2,
        Protected => 1,
    },
    0xc621 => {
        Name => 'ColorMatrix1',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc622 => {
        Name => 'ColorMatrix2',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc623 => {
        Name => 'CameraCalibration1',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc624 => {
        Name => 'CameraCalibration2',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc625 => {
        Name => 'ReductionMatrix1',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc626 => {
        Name => 'ReductionMatrix2',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc627 => {
        Name => 'AnalogBalance',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc628 => {
        Name => 'AsShotNeutral',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc629 => {
        Name => 'AsShotWhiteXY',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => 2,
        Protected => 1,
    },
    0xc62a => {
        Name => 'BaselineExposure',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Protected => 1,
    },
    0xc62b => {
        Name => 'BaselineNoise',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Protected => 1,
    },
    0xc62c => {
        Name => 'BaselineSharpness',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Protected => 1,
    },
    0xc62d => {
        Name => 'BayerGreenSplit',
        Writable => 'int32u',
        WriteGroup => 'SubIFD',
        Protected => 1,
    },
    0xc62e => {
        Name => 'LinearResponseLimit',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Protected => 1,
    },
    0xc62f => {
        Name => 'CameraSerialNumber',
        Groups => { 2 => 'Camera' },
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0xc630 => {
        Name => 'DNGLensInfo',
        Groups => { 2 => 'Camera' },
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => 4,
        PrintConv =>\&PrintLensInfo,
        PrintConvInv => \&ConvertLensInfo,
    },
    0xc631 => {
        Name => 'ChromaBlurRadius',
        Writable => 'rational64u',
        WriteGroup => 'SubIFD',
        Protected => 1,
    },
    0xc632 => {
        Name => 'AntiAliasStrength',
        Writable => 'rational64u',
        WriteGroup => 'SubIFD',
        Protected => 1,
    },
    0xc633 => {
        Name => 'ShadowScale',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Protected => 1,
    },
    0xc634 => [
        {
            Condition => '$$self{TIFF_TYPE} =~ /^(ARW|SR2)$/',
            Name => 'SR2Private',
            Groups => { 1 => 'SR2' },
            Flags => 'SubIFD',
            Format => 'int32u',
            # some utilites have problems unless this is int8u format:
            # - Adobe Camera Raw 5.3 gives an error
            # - Apple Preview 10.5.8 gets the wrong white balance
            FixFormat => 'int8u', # (stupid Sony)
            WriteGroup => 'IFD0', # (for Validate)
            SubDirectory => {
                DirName => 'SR2Private',
                TagTable => 'Image::ExifTool::Sony::SR2Private',
                Start => '$val',
            },
        },
        {
            Condition => '$$valPt =~ /^Adobe\0/',
            Name => 'DNGAdobeData',
            Flags => [ 'Binary', 'Protected' ],
            Writable => 'undef', # (writable directory!) (to make it possible to delete this mess)
            WriteGroup => 'IFD0',
            NestedHtmlDump => 1,
            SubDirectory => { TagTable => 'Image::ExifTool::DNG::AdobeData' },
            Format => 'undef',  # written incorrectly as int8u (change to undef for speed)
        },
        {
            # Pentax/Samsung models that write AOC maker notes in JPG images:
            # K-5,K-7,K-m,K-x,K-r,K10D,K20D,K100D,K110D,K200D,K2000,GX10,GX20
            # (Note: the following expression also appears in WriteExif.pl)
            Condition => q{
                $$valPt =~ /^(PENTAX |SAMSUNG)\0/ and
                $$self{Model} =~ /\b(K(-[57mrx]|(10|20|100|110|200)D|2000)|GX(10|20))\b/
            },
            Name => 'MakerNotePentax',
            MakerNotes => 1,    # (causes "MakerNotes header" to be identified in HtmlDump output)
            Binary => 1,
            WriteGroup => 'IFD0', # (for Validate)
            # Note: Don't make this block-writable for a few reasons:
            # 1) It would be dangerous (possibly confusing Pentax software)
            # 2) It is a different format from the JPEG version of MakerNotePentax
            # 3) It is converted to JPEG format by RebuildMakerNotes() when copying
            SubDirectory => {
                TagTable => 'Image::ExifTool::Pentax::Main',
                Start => '$valuePtr + 10',
                Base => '$start - 10',
                ByteOrder => 'Unknown', # easier to do this than read byteorder word
            },
            Format => 'undef',  # written incorrectly as int8u (change to undef for speed)
        },
        {
            # must duplicate the above tag with a different name for more recent
            # Pentax models which use the "PENTAX" instead of the "AOC" maker notes
            # in JPG images (needed when copying maker notes from DNG to JPG)
            Condition => '$$valPt =~ /^(PENTAX |SAMSUNG)\0/',
            Name => 'MakerNotePentax5',
            MakerNotes => 1,
            Binary => 1,
            WriteGroup => 'IFD0', # (for Validate)
            SubDirectory => {
                TagTable => 'Image::ExifTool::Pentax::Main',
                Start => '$valuePtr + 10',
                Base => '$start - 10',
                ByteOrder => 'Unknown',
            },
            Format => 'undef',
        },
        {
            Name => 'DNGPrivateData',
            Flags => [ 'Binary', 'Protected' ],
            Format => 'undef',
            Writable => 'undef',
            WriteGroup => 'IFD0',
        },
    ],
    0xc635 => {
        Name => 'MakerNoteSafety',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        PrintConv => {
            0 => 'Unsafe',
            1 => 'Safe',
        },
    },
    0xc640 => { #15
        Name => 'RawImageSegmentation',
        # (int16u[3], not writable)
        Notes => q{
            used in segmented Canon CR2 images.  3 numbers: 1. Number of segments minus
            one; 2. Pixel width of segments except last; 3. Pixel width of last segment
        },
    },
    0xc65a => {
        Name => 'CalibrationIlluminant1',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Protected => 1,
        SeparateTable => 'LightSource',
        PrintConv => \%lightSource,
    },
    0xc65b => {
        Name => 'CalibrationIlluminant2',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Protected => 1,
        SeparateTable => 'LightSource',
        PrintConv => \%lightSource,
    },
    0xc65c => {
        Name => 'BestQualityScale',
        Writable => 'rational64u',
        WriteGroup => 'SubIFD',
        Protected => 1,
    },
    0xc65d => {
        Name => 'RawDataUniqueID',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Count => 16,
        Protected => 1,
        ValueConv => 'uc(unpack("H*",$val))',
        ValueConvInv => 'pack("H*", $val)',
    },
    0xc660 => { #3
        Name => 'AliasLayerMetadata',
        Notes => 'used by Alias Sketchbook Pro',
    },
    0xc68b => {
        Name => 'OriginalRawFileName',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc68c => {
        Name => 'OriginalRawFileData', # (writable directory!)
        Writable => 'undef', # must be defined here so tag will be extracted if specified
        WriteGroup => 'IFD0',
        Flags => [ 'Binary', 'Protected' ],
        SubDirectory => {
            TagTable => 'Image::ExifTool::DNG::OriginalRaw',
        },
    },
    0xc68d => {
        Name => 'ActiveArea',
        Writable => 'int32u',
        WriteGroup => 'SubIFD',
        Count => 4,
        Protected => 1,
    },
    0xc68e => {
        Name => 'MaskedAreas',
        Writable => 'int32u',
        WriteGroup => 'SubIFD',
        Count => -1,
        Protected => 1,
    },
    0xc68f => {
        Name => 'AsShotICCProfile', # (writable directory)
        Binary => 1,
        Writable => 'undef', # must be defined here so tag will be extracted if specified
        WriteGroup => 'IFD0',
        Protected => 1,
        WriteCheck => q{
            require Image::ExifTool::ICC_Profile;
            return Image::ExifTool::ICC_Profile::ValidateICC(\$val);
        },
        SubDirectory => {
            DirName => 'AsShotICCProfile',
            TagTable => 'Image::ExifTool::ICC_Profile::Main',
        },
    },
    0xc690 => {
        Name => 'AsShotPreProfileMatrix',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc691 => {
        Name => 'CurrentICCProfile', # (writable directory)
        Binary => 1,
        Writable => 'undef', # must be defined here so tag will be extracted if specified
        SubDirectory => {
            DirName => 'CurrentICCProfile',
            TagTable => 'Image::ExifTool::ICC_Profile::Main',
        },
        Writable => 'undef',
        WriteGroup => 'IFD0',
        Protected => 1,
        WriteCheck => q{
            require Image::ExifTool::ICC_Profile;
            return Image::ExifTool::ICC_Profile::ValidateICC(\$val);
        },
    },
    0xc692 => {
        Name => 'CurrentPreProfileMatrix',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc6bf => {
        Name => 'ColorimetricReference',
        Writable => 'int16u',
        WriteGroup => 'IFD0',
        Protected => 1,
    },
    0xc6c5 => { Name => 'SRawType', Description => 'SRaw Type', WriteGroup => 'IFD0' }, #exifprobe (CR2 proprietary)
    0xc6d2 => { #JD (Panasonic DMC-TZ5)
        # this text is UTF-8 encoded (hooray!) - PH (TZ5)
        Name => 'PanasonicTitle',
        Format => 'string', # written incorrectly as 'undef'
        Notes => 'proprietary Panasonic tag used for baby/pet name, etc',
        Writable => 'undef',
        WriteGroup => 'IFD0',
        # panasonic always records this tag (64 zero bytes),
        # so ignore it unless it contains valid information
        RawConv => 'length($val) ? $val : undef',
        ValueConv => '$self->Decode($val, "UTF8")',
        ValueConvInv => '$self->Encode($val,"UTF8")',
    },
    0xc6d3 => { #PH (Panasonic DMC-FS7)
        Name => 'PanasonicTitle2',
        Format => 'string', # written incorrectly as 'undef'
        Notes => 'proprietary Panasonic tag used for baby/pet name with age',
        Writable => 'undef',
        WriteGroup => 'IFD0',
        # panasonic always records this tag (128 zero bytes),
        # so ignore it unless it contains valid information
        RawConv => 'length($val) ? $val : undef',
        ValueConv => '$self->Decode($val, "UTF8")',
        ValueConvInv => '$self->Encode($val,"UTF8")',
    },
    # 0xc6dc - int32u[4]: found in CR2 images (PH, 7DmkIII)
    # 0xc6dd - int16u[256]: found in CR2 images (PH, 5DmkIV)
    0xc6f3 => {
        Name => 'CameraCalibrationSig',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc6f4 => {
        Name => 'ProfileCalibrationSig',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc6f5 => {
        Name => 'ProfileIFD', # (ExtraCameraProfiles)
        Groups => { 1 => 'ProfileIFD' },
        Flags => 'SubIFD',
        WriteGroup => 'IFD0', # (only for Validate)
        SubDirectory => {
            ProcessProc => \&ProcessTiffIFD,
            WriteProc => \&ProcessTiffIFD,
            DirName => 'ProfileIFD',
            Start => '$val',
            Base => '$start',   # offsets relative to start of TIFF-like header
            MaxSubdirs => 10,
            Magic => 0x4352,    # magic number for TIFF-like header
        },
    },
    0xc6f6 => {
        Name => 'AsShotProfileName',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc6f7 => {
        Name => 'NoiseReductionApplied',
        Writable => 'rational64u',
        WriteGroup => 'SubIFD',
        Protected => 1,
    },
    0xc6f8 => {
        Name => 'ProfileName',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc6f9 => {
        Name => 'ProfileHueSatMapDims',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Count => 3,
        Protected => 1,
    },
    0xc6fa => {
        Name => 'ProfileHueSatMapData1',
        %longBin,
        Writable => 'float',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc6fb => {
        Name => 'ProfileHueSatMapData2',
        %longBin,
        Writable => 'float',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc6fc => {
        Name => 'ProfileToneCurve',
        Writable => 'float',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
        Binary => 1,
    },
    0xc6fd => {
        Name => 'ProfileEmbedPolicy',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Protected => 1,
        PrintConv => {
            0 => 'Allow Copying',
            1 => 'Embed if Used',
            2 => 'Never Embed',
            3 => 'No Restrictions',
        },
    },
    0xc6fe => {
        Name => 'ProfileCopyright',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc714 => {
        Name => 'ForwardMatrix1',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc715 => {
        Name => 'ForwardMatrix2',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
    },
    0xc716 => {
        Name => 'PreviewApplicationName',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc717 => {
        Name => 'PreviewApplicationVersion',
        Writable => 'string',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc718 => {
        Name => 'PreviewSettingsName',
        Writable => 'string',
        WriteGroup => 'IFD0',
        Protected => 1,
        %utf8StringConv,
    },
    0xc719 => {
        Name => 'PreviewSettingsDigest',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Protected => 1,
        ValueConv => 'unpack("H*", $val)',
        ValueConvInv => 'pack("H*", $val)',
    },
    0xc71a => {
        Name => 'PreviewColorSpace',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Protected => 1,
        PrintConv => {
            0 => 'Unknown',
            1 => 'Gray Gamma 2.2',
            2 => 'sRGB',
            3 => 'Adobe RGB',
            4 => 'ProPhoto RGB',
        },
    },
    0xc71b => {
        Name => 'PreviewDateTime',
        Groups => { 2 => 'Time' },
        Writable => 'string',
        Shift => 'Time',
        WriteGroup => 'IFD0',
        Protected => 1,
        ValueConv => q{
            require Image::ExifTool::XMP;
            return Image::ExifTool::XMP::ConvertXMPDate($val);
        },
        ValueConvInv => q{
            require Image::ExifTool::XMP;
            return Image::ExifTool::XMP::FormatXMPDate($val);
        },
        PrintConv => '$self->ConvertDateTime($val)',
        PrintConvInv => '$self->InverseDateTime($val,1,1)',
    },
    0xc71c => {
        Name => 'RawImageDigest',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Count => 16,
        Protected => 1,
        ValueConv => 'unpack("H*", $val)',
        ValueConvInv => 'pack("H*", $val)',
    },
    0xc71d => {
        Name => 'OriginalRawFileDigest',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Count => 16,
        Protected => 1,
        ValueConv => 'unpack("H*", $val)',
        ValueConvInv => 'pack("H*", $val)',
    },
    0xc71e => 'SubTileBlockSize',
    0xc71f => 'RowInterleaveFactor',
    0xc725 => {
        Name => 'ProfileLookTableDims',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Count => 3,
        Protected => 1,
    },
    0xc726 => {
        Name => 'ProfileLookTableData',
        Writable => 'float',
        WriteGroup => 'IFD0',
        Count => -1,
        Protected => 1,
        Binary => 1,
    },
    0xc740 => { # DNG 1.3
        Name => 'OpcodeList1',
        Writable => 'undef',
        WriteGroup => 'SubIFD',
        Protected => 1,
        Binary => 1,
        # opcodes:
        # 1 => 'WarpRectilinear',
        # 2 => 'WarpFisheye',
        # 3 => 'FixVignetteRadial',
        # 4 => 'FixBadPixelsConstant',
        # 5 => 'FixBadPixelsList',
        # 6 => 'TrimBounds',
        # 7 => 'MapTable',
        # 8 => 'MapPolynomial',
        # 9 => 'GainMap',
        # 10 => 'DeltaPerRow',
        # 11 => 'DeltaPerColumn',
        # 12 => 'ScalePerRow',
        # 13 => 'ScalePerColumn',
    },
    0xc741 => { # DNG 1.3
        Name => 'OpcodeList2',
        Writable => 'undef',
        WriteGroup => 'SubIFD',
        Protected => 1,
        Binary => 1,
    },
    0xc74e => { # DNG 1.3
        Name => 'OpcodeList3',
        Writable => 'undef',
        WriteGroup => 'SubIFD',
        Protected => 1,
        Binary => 1,
    },
    0xc761 => { # DNG 1.3
        Name => 'NoiseProfile',
        Writable => 'double',
        WriteGroup => 'SubIFD',
        Count => -1,
        Protected => 1,
    },
    0xc763 => { #28
        Name => 'TimeCodes',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Count => -1, # (8 * number of time codes, max 10)
        ValueConv => q{
            my @a = split ' ', $val;
            my @v;
            push @v, join('.', map { sprintf('%.2x',$_) } splice(@a,0,8)) while @a >= 8;
            join ' ', @v;
        },
        ValueConvInv => q{
            my @a = map hex, split /[. ]+/, $val;
            join ' ', @a;
        },
        # Note: Currently ignore the flags:
        #   byte 0 0x80 - color frame
        #   byte 0 0x40 - drop frame
        #   byte 1 0x80 - field phase
        PrintConv => q{
            my @a = map hex, split /[. ]+/, $val;
            my @v;
            while (@a >= 8) {
                my $str = sprintf("%.2x:%.2x:%.2x.%.2x", $a[3]&0x3f,
                                 $a[2]&0x7f, $a[1]&0x7f, $a[0]&0x3f);
                if ($a[3] & 0x80) { # date+timezone exist if BGF2 is set
                    my $tz = $a[7] & 0x3f;
                    my $bz = sprintf('%.2x', $tz);
                    $bz = 100 if $bz =~ /[a-f]/i; # not BCD
                    if ($bz < 26) {
                        $tz = ($bz < 13 ? 0 : 26) - $bz;
                    } elsif ($bz == 32) {
                        $tz = 12.75;
                    } elsif ($bz >= 28 and $bz <= 31) {
                        $tz = 0;    # UTC
                    } elsif ($bz < 100) {
                        undef $tz;  # undefined or user-defined
                    } elsif ($tz < 0x20) {
                        $tz = (($tz < 0x10 ? 10 : 20) - $tz) - 0.5;
                    } else {
                        $tz = (($tz < 0x30 ? 53 : 63) - $tz) + 0.5;
                    }
                    if ($a[7] & 0x80) { # MJD format (/w UTC time)
                        my ($h,$m,$s,$f) = split /[:.]/, $str;
                        my $jday = sprintf('%x%.2x%.2x', reverse @a[4..6]);
                        $str = ConvertUnixTime(($jday - 40587) * 24 * 3600
                                 + ((($h+$tz) * 60) + $m) * 60 + $s) . ".$f";
                        $str =~ s/^(\d+):(\d+):(\d+) /$1-$2-${3}T/;
                    } else { # YYMMDD (Note: CinemaDNG 1.1 example seems wrong)
                        my $yr = sprintf('%.2x',$a[6]) + 1900;
                        $yr += 100 if $yr < 1970;
                        $str = sprintf('%d-%.2x-%.2xT%s',$yr,$a[5],$a[4],$str);
                    }
                    $str .= TimeZoneString($tz*60) if defined $tz;
                }
                push @v, $str;
                splice @a, 0, 8;
            }
            join ' ', @v;
        },
        PrintConvInv => q{
            my @a = split ' ', $val;
            my @v;
            foreach (@a) {
                my @td = reverse split /T/;
                my $tz = 0x39; # default to unknown timezone
                if ($td[0] =~ s/([-+])(\d+):(\d+)$//) {
                    if ($3 == 0) {
                        $tz = hex(($1 eq '-') ? $2 : 0x26 - $2);
                    } elsif ($3 == 30) {
                        if ($1 eq '-') {
                            $tz = $2 + 0x0a;
                            $tz += 0x0a if $tz > 0x0f;
                        } else {
                            $tz = 0x3f - $2;
                            $tz -= 0x0a if $tz < 0x3a;
                        }
                    } elsif ($3 == 45) {
                        $tz = 0x32 if $1 eq '+' and $2 == 12;
                    }
                }
                my @t = split /[:.]/, $td[0];
                push @t, '00' while @t < 4;
                my $bg;
                if ($td[1]) {
                    # date was specified: fill in date & timezone
                    my @d = split /[-]/, $td[1];
                    next if @d < 3;
                    $bg = sprintf('.%.2d.%.2d.%.2d.%.2x', $d[2], $d[1], $d[0]%100, $tz);
                    $t[0] = sprintf('%.2x', hex($t[0]) + 0xc0); # set BGF1+BGF2
                } else { # time only
                    $bg = '.00.00.00.00';
                }
                push @v, join('.', reverse(@t[0..3])) . $bg;
            }
            join ' ', @v;
        },
    },
    0xc764 => { #28
        Name => 'FrameRate',
        Writable => 'rational64s',
        WriteGroup => 'IFD0',
        PrintConv => 'int($val * 1000 + 0.5) / 1000',
        PrintConvInv => '$val',
    },
    0xc772 => { #28
        Name => 'TStop',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => -1, # (1 or 2)
        PrintConv => 'join("-", map { sprintf("%.2f",$_) } split " ", $val)',
        PrintConvInv => '$val=~tr/-/ /; $val',
    },
    0xc789 => { #28
        Name => 'ReelName',
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0xc791 => { # DNG 1.4
        Name => 'OriginalDefaultFinalSize',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Count => 2,
        Protected => 1,
    },
    0xc792 => { # DNG 1.4
        Name => 'OriginalBestQualitySize',
        Notes => 'called OriginalBestQualityFinalSize by the DNG spec',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Count => 2,
        Protected => 1,
    },
    0xc793 => { # DNG 1.4
        Name => 'OriginalDefaultCropSize',
        Writable => 'rational64u',
        WriteGroup => 'IFD0',
        Count => 2,
        Protected => 1,
    },
    0xc7a1 => {  #28
        Name => 'CameraLabel',
        Writable => 'string',
        WriteGroup => 'IFD0',
    },
    0xc7a3 => { # DNG 1.4
        Name => 'ProfileHueSatMapEncoding',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Protected => 1,
        PrintConv => {
            0 => 'Linear',
            1 => 'sRGB',
        },
    },
    0xc7a4 => { # DNG 1.4
        Name => 'ProfileLookTableEncoding',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Protected => 1,
        PrintConv => {
            0 => 'Linear',
            1 => 'sRGB',
        },
    },
    0xc7a5 => { # DNG 1.4
        Name => 'BaselineExposureOffset',
        Writable => 'rational64s', # (incorrectly "RATIONAL" in DNG 1.4 spec)
        WriteGroup => 'IFD0',
        Protected => 1,
    },
    0xc7a6 => { # DNG 1.4
        Name => 'DefaultBlackRender',
        Writable => 'int32u',
        WriteGroup => 'IFD0',
        Protected => 1,
        PrintConv => {
            0 => 'Auto',
            1 => 'None',
        },
    },
    0xc7a7 => { # DNG 1.4
        Name => 'NewRawImageDigest',
        Format => 'undef',
        Writable => 'int8u',
        WriteGroup => 'IFD0',
        Count => 16,
        Protected => 1,
        ValueConv => 'unpack("H*", $val)',
        ValueConvInv => 'pack("H*", $val)',
    },
    0xc7a8 => { # DNG 1.4
        Name => 'RawToPreviewGain',
        Writable => 'double',
        WriteGroup => 'IFD0',
        Protected => 1,
    },
    # 0xc7aa - undocumented DNG tag written by LR4 (int32u[1] - val=256, related to fast load data?)
    0xc7b5 => { # DNG 1.4
        Name => 'DefaultUserCrop',
        Writable => 'rational64u',
        WriteGroup => 'SubIFD',
        Count => 4,
        Protected => 1,
    },
    0xea1c => { #13
        Name => 'Padding',
        Binary => 1,
        Protected => 1,
        Writable => 'undef',
        # must start with 0x1c 0xea by the WM Photo specification
        # (not sure what should happen if padding is only 1 byte)
        # (why does MicrosoftPhoto write "1c ea 00 00 00 08"?)
        RawConvInv => '$val=~s/^../\x1c\xea/s; $val',
    },
    0xea1d => {
        Name => 'OffsetSchema',
        Notes => "Microsoft's ill-conceived maker note offset difference",
        Protected => 1,
        Writable => 'int32s',
        # From the Microsoft documentation:
        #
        #     Any time the "Maker Note" is relocated by Windows, the Exif MakerNote
        #     tag (37500) is updated automatically to reference the new location. In
        #     addition, Windows records the offset (or difference) between the old and
        #     new locations in the Exif OffsetSchema tag (59933). If the "Maker Note"
        #     contains relative references, the developer can add the value in
        #     OffsetSchema to the original references to find the correct information.
        #
        # My recommendation is for other developers to ignore this tag because the
        # information it contains is unreliable. It will be wrong if the image has
        # been subsequently edited by another application that doesn't recognize the
        # new Microsoft tag.
        #
        # The new tag unfortunately only gives the difference between the new maker
        # note offset and the original offset. Instead, it should have been designed
        # to store the original offset. The new offset may change if the image is
        # edited, which will invalidate the tag as currently written. If instead the
        # original offset had been stored, the new difference could be easily
        # calculated because the new maker note offset is known.
        #
        # I exchanged emails with a Microsoft technical representative, pointing out
        # this problem shortly after they released the update (Feb 2007), but so far
        # they have taken no steps to address this.
    },
    # 0xefee - int16u: 0 - seen this from a WIC-scanned image

    # tags in the range 0xfde8-0xfe58 have been observed in PS7 files
    # generated from RAW images.  They are all strings with the
    # tag name at the start of the string.  To accomodate these types
    # of tags, all tags with values above 0xf000 are handled specially
    # by ProcessExif().
    0xfde8 => {
        Name => 'OwnerName',
        Condition => '$$self{TIFF_TYPE} ne "DCR"', # (used for another purpose in Kodak DCR images)
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Owner's Name: $val"},
        Notes => q{
            tags 0xfde8-0xfdea and 0xfe4c-0xfe58 are generated by Photoshop Camera RAW.
            Some names are the same as other EXIF tags, but ExifTool will avoid writing
            these unless they already exist in the file
        },
    },
    0xfde9 => {
        Name => 'SerialNumber',
        Condition => '$$self{TIFF_TYPE} ne "DCR"', # (used for another purpose in Kodak DCR SubIFD)
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Serial Number: $val"},
    },
    0xfdea => {
        Name => 'Lens',
        Condition => '$$self{TIFF_TYPE} ne "DCR"', # (used for another purpose in Kodak DCR SubIFD)
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Lens: $val"},
    },
    0xfe4c => {
        Name => 'RawFile',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Raw File: $val"},
    },
    0xfe4d => {
        Name => 'Converter',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Converter: $val"},
    },
    0xfe4e => {
        Name => 'WhiteBalance',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"White Balance: $val"},
    },
    0xfe51 => {
        Name => 'Exposure',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Exposure: $val"},
    },
    0xfe52 => {
        Name => 'Shadows',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Shadows: $val"},
    },
    0xfe53 => {
        Name => 'Brightness',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Brightness: $val"},
    },
    0xfe54 => {
        Name => 'Contrast',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Contrast: $val"},
    },
    0xfe55 => {
        Name => 'Saturation',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Saturation: $val"},
    },
    0xfe56 => {
        Name => 'Sharpness',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Sharpness: $val"},
    },
    0xfe57 => {
        Name => 'Smoothness',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Smoothness: $val"},
    },
    0xfe58 => {
        Name => 'MoireFilter',
        Avoid => 1,
        PSRaw => 1,
        Writable => 'string',
        ValueConv => '$val=~s/^.*: //;$val',
        ValueConvInv => q{"Moire Filter: $val"},
    },

    #-------------
    0xfe00 => {
        Name => 'KDC_IFD',
        Groups => { 1 => 'KDC_IFD' },
        Flags => 'SubIFD',
        Notes => 'used in some Kodak KDC images',
        SubDirectory => {
            TagTable => 'Image::ExifTool::Kodak::KDC_IFD',
            DirName => 'KDC_IFD',
            Start => '$val',
        },
    },
);

# conversions for Composite SubSec date/time tags
my %subSecConv = (
    # @val array: 0) date/time, 1) sub-seconds, 2) time zone offset
    RawConv => q{
        my $v;
        if (defined $val[1] and $val[1]=~/^(\d+)/) {
            my $subSec = $1;
            # be careful here just in case the time already contains a timezone (contrary to spec)
            undef $v unless ($v = $val[0]) =~ s/( \d{2}:\d{2}:\d{2})/$1\.$subSec/;
        }
        if (defined $val[2] and $val[0]!~/[-+]/ and $val[2]=~/^([-+])(\d{1,2}):(\d{2})/) {
            $v = ($v || $val[0]) . sprintf('%s%.2d:%.2d', $1, $2, $3);
        }
        return $v;
    },
    PrintConv => '$self->ConvertDateTime($val)',
    PrintConvInv => '$self->InverseDateTime($val)',
);

# EXIF Composite tags (plus other more general Composite tags)
%Image::ExifTool::Exif::Composite = (
    GROUPS => { 2 => 'Image' },
    ImageSize => {
        Require => {
            0 => 'ImageWidth',
            1 => 'ImageHeight',
        },
        Desire => {
            2 => 'ExifImageWidth',
            3 => 'ExifImageHeight',
        },
        # use ExifImageWidth/Height only for Canon and Phase One TIFF-base RAW images
        ValueConv => q{
            return "$val[2]x$val[3]" if $val[2] and $val[3] and
                    $$self{TIFF_TYPE} =~ /^(CR2|Canon 1D RAW|IIQ|EIP)$/;
            return "$val[0]x$val[1]" if IsFloat($val[0]) and IsFloat($val[1]);
            return undef;
        },
    },
    Megapixels => {
        Require => 'ImageSize',
        ValueConv => 'my @d = ($val =~ /\d+/g); $d[0] * $d[1] / 1000000',
        PrintConv => 'sprintf("%.*f", ($val >= 1 ? 1 : ($val >= 0.001 ? 3 : 6)), $val)',
    },
    # pick the best shutter speed value
    ShutterSpeed => {
        Desire => {
            0 => 'ExposureTime',
            1 => 'ShutterSpeedValue',
            2 => 'BulbDuration',
        },
        ValueConv => '($val[2] and $val[2]>0) ? $val[2] : (defined($val[0]) ? $val[0] : $val[1])',
        PrintConv => 'Image::ExifTool::Exif::PrintExposureTime($val)',
    },
    Aperture => {
        Desire => {
            0 => 'FNumber',
            1 => 'ApertureValue',
        },
        RawConv => '($val[0] || $val[1]) ? $val : undef',
        ValueConv => '$val[0] || $val[1]',
        PrintConv => 'Image::ExifTool::Exif::PrintFNumber($val)',
    },
    LightValue => {
        Notes => q{
            calculated LV = 2 * log2(Aperture) - log2(ShutterSpeed) - log2(ISO/100);
            similar to exposure value but normalized to ISO 100
        },
        Require => {
            0 => 'Aperture',
            1 => 'ShutterSpeed',
            2 => 'ISO',
        },
        ValueConv => 'Image::ExifTool::Exif::CalculateLV($val[0],$val[1],$prt[2])',
        PrintConv => 'sprintf("%.1f",$val)',
    },
    FocalLength35efl => { #26/PH
        Description => 'Focal Length',
        Notes => 'this value may be incorrect if the image has been resized',
        Groups => { 2 => 'Camera' },
        Require => {
            0 => 'FocalLength',
        },
        Desire => {
            1 => 'ScaleFactor35efl',
        },
        ValueConv => 'ToFloat(@val); ($val[0] || 0) * ($val[1] || 1)',
        PrintConv => '$val[1] ? sprintf("%.1f mm (35 mm equivalent: %.1f mm)", $val[0], $val) : sprintf("%.1f mm", $val)',
    },
    ScaleFactor35efl => { #26/PH
        Description => 'Scale Factor To 35 mm Equivalent',
        Notes => q{
            this value and any derived values may be incorrect if the image has been
            resized
        },
        Groups => { 2 => 'Camera' },
        Desire => {
            0 => 'FocalLength',
            1 => 'FocalLengthIn35mmFormat',
            2 => 'Composite:DigitalZoom',
            3 => 'FocalPlaneDiagonal',
            4 => 'SensorSize',
            5 => 'FocalPlaneXSize',
            6 => 'FocalPlaneYSize',
            7 => 'FocalPlaneResolutionUnit',
            8 => 'FocalPlaneXResolution',
            9 => 'FocalPlaneYResolution',
           10 => 'ExifImageWidth',
           11 => 'ExifImageHeight',
           12 => 'CanonImageWidth',
           13 => 'CanonImageHeight',
           14 => 'ImageWidth',
           15 => 'ImageHeight',
        },
        ValueConv => 'Image::ExifTool::Exif::CalcScaleFactor35efl($self, @val)',
        PrintConv => 'sprintf("%.1f", $val)',
    },
    CircleOfConfusion => {
        Notes => q{
            calculated as D/1440, where D is the focal plane diagonal in mm.  This value
            may be incorrect if the image has been resized
        },
        Groups => { 2 => 'Camera' },
        Require => 'ScaleFactor35efl',
        ValueConv => 'sqrt(24*24+36*36) / ($val * 1440)',
        PrintConv => 'sprintf("%.3f mm",$val)',
    },
    HyperfocalDistance => {
        Notes => 'this value may be incorrect if the image has been resized',
        Groups => { 2 => 'Camera' },
        Require => {
            0 => 'FocalLength',
            1 => 'Aperture',
            2 => 'CircleOfConfusion',
        },
        ValueConv => q{
            ToFloat(@val);
            return 'inf' unless $val[1] and $val[2];
            return $val[0] * $val[0] / ($val[1] * $val[2] * 1000);
        },
        PrintConv => 'sprintf("%.2f m", $val)',
    },
    DOF => {
        Description => 'Depth Of Field',
        Notes => 'this value may be incorrect if the image has been resized',
        Require => {
            0 => 'FocalLength',
            1 => 'Aperture',
            2 => 'CircleOfConfusion',
        },
        Desire => {
            3 => 'FocusDistance',   # focus distance in metres (0 is infinity)
            4 => 'SubjectDistance',
            5 => 'ObjectDistance',
            6 => 'ApproximateFocusDistance ',
            7 => 'FocusDistanceLower',
            8 => 'FocusDistanceUpper',
        },
        ValueConv => q{
            ToFloat(@val);
            my ($d, $f) = ($val[3], $val[0]);
            if (defined $d) {
                $d or $d = 1e10;    # (use large number for infinity)
            } else {
                $d = $val[4] || $val[5] || $val[6];
                unless (defined $d) {
                    return undef unless defined $val[7] and defined $val[8];
                    $d = ($val[7] + $val[8]) / 2;
                }
            }
            return 0 unless $f and $val[2];
            my $t = $val[1] * $val[2] * ($d * 1000 - $f) / ($f * $f);
            my @v = ($d / (1 + $t), $d / (1 - $t));
            $v[1] < 0 and $v[1] = 0; # 0 means 'inf'
            return join(' ',@v);
        },
        PrintConv => q{
            $val =~ tr/,/./;    # in case locale is whacky
            my @v = split ' ', $val;
            $v[1] or return sprintf("inf (%.2f m - inf)", $v[0]);
            my $dof = $v[1] - $v[0];
            my $fmt = ($dof>0 and $dof<0.02) ? "%.3f" : "%.2f";
            return sprintf("$fmt m ($fmt - $fmt m)",$dof,$v[0],$v[1]);
        },
    },
    FOV => {
        Description => 'Field Of View',
        Notes => q{
            calculated for the long image dimension.  This value may be incorrect for
            fisheye lenses, or if the image has been resized
        },
        Require => {
            0 => 'FocalLength',
            1 => 'ScaleFactor35efl',
        },
        Desire => {
            2 => 'FocusDistance', # (multiply by 1000 to convert to mm)
        },
        # ref http://www.bobatkins.com/photography/technical/field_of_view.html
        # (calculations below apply to rectilinear lenses only, not fisheye)
        ValueConv => q{
            ToFloat(@val);
            return undef unless $val[0] and $val[1];
            my $corr = 1;
            if ($val[2]) {
                my $d = 1000 * $val[2] - $val[0];
                $corr += $val[0]/$d if $d > 0;
            }
            my $fd2 = atan2(36, 2*$val[0]*$val[1]*$corr);
            my @fov = ( $fd2 * 360 / 3.14159 );
            if ($val[2] and $val[2] > 0 and $val[2] < 10000) {
                push @fov, 2 * $val[2] * sin($fd2) / cos($fd2);
            }
            return join(' ', @fov);
        },
        PrintConv => q{
            my @v = split(' ',$val);
            my $str = sprintf("%.1f deg", $v[0]);
            $str .= sprintf(" (%.2f m)", $v[1]) if $v[1];
            return $str;
        },
    },
    # generate DateTimeOriginal from Date and Time Created if not extracted already
    DateTimeOriginal => {
        Condition => 'not defined $$self{VALUE}{DateTimeOriginal}',
        Description => 'Date/Time Original',
        Groups => { 2 => 'Time' },
        Desire => {
            0 => 'DateTimeCreated',
            1 => 'DateCreated',
            2 => 'TimeCreated',
        },
        RawConv => '($val[1] and $val[2]) ? $val : undef',
        ValueConv => q{
            return $val[0] if $val[0] and $val[0]=~/ /;
            return "$val[1] $val[2]";
        },
        PrintConv => '$self->ConvertDateTime($val)',
    },
    ThumbnailImage => {
        Groups => { 0 => 'EXIF', 1 => 'IFD1', 2 => 'Preview' },
        Writable => 1,
        WriteGroup => 'All',
        WriteCheck => '$self->CheckImage(\$val)',
        WriteAlso => {
            # (the 0xfeedfeed values are translated in the Exif write routine)
            ThumbnailOffset => 'defined $val ? 0xfeedfeed : undef',
            ThumbnailLength => 'defined $val ? 0xfeedfeed : undef',
        },
        Require => {
            0 => 'ThumbnailOffset',
            1 => 'ThumbnailLength',
        },
        Notes => q{
            this tag is writable, and may be used to update existing thumbnails, but may
            only create a thumbnail in IFD1 of certain types of files.  Note that for
            this and other Composite embedded-image tags the family 0 and 1 groups match
            those of the originating tags
        },
        # retrieve the thumbnail from our EXIF data
        RawConv => q{
            @grps = $self->GetGroup($$val{0});  # set groups from ThumbnailOffsets
            Image::ExifTool::Exif::ExtractImage($self,$val[0],$val[1],"ThumbnailImage");
        },
    },
    ThumbnailTIFF => {
        Groups => { 2 => 'Preview' },
        Require => {
            0 => 'SubfileType',
            1 => 'Compression',
            2 => 'ImageWidth',
            3 => 'ImageHeight',
            4 => 'BitsPerSample',
            5 => 'PhotometricInterpretation',
            6 => 'StripOffsets',
            7 => 'SamplesPerPixel',
            8 => 'RowsPerStrip',
            9 => 'StripByteCounts',
        },
        Desire => {
            10 => 'PlanarConfiguration',
            11 => 'Orientation',
        },
        # rebuild the TIFF thumbnail from our EXIF data
        RawConv => q{
            my $tiff;
            ($tiff, @grps) = Image::ExifTool::Exif::RebuildTIFF($self, @val);
            return $tiff;
        },
    },
    PreviewImage => {
        Groups => { 0 => 'EXIF', 1 => 'SubIFD', 2 => 'Preview' },
        Writable => 1,
        WriteGroup => 'All',
        WriteCheck => '$self->CheckImage(\$val)',
        DelCheck => '$val = ""; return undef', # can't delete, so set to empty string
        WriteAlso => {
            PreviewImageStart  => 'defined $val ? 0xfeedfeed : undef',
            PreviewImageLength => 'defined $val ? 0xfeedfeed : undef',
            PreviewImageValid  => 'defined $val and length $val ? 1 : 0', # (for Olympus)
        },
        Require => {
            0 => 'PreviewImageStart',
            1 => 'PreviewImageLength',
        },
        Desire => {
            2 => 'PreviewImageValid',
            # (DNG and A100 ARW may be have 2 preview images)
            3 => 'PreviewImageStart (1)',
            4 => 'PreviewImageLength (1)',
        },
        Notes => q{
            this tag is writable, and may be used to update existing embedded images,
            but not create or delete them
        },
        # note: extract 2nd preview, but ignore double-referenced preview
        # (in A100 ARW images, the 2nd PreviewImageLength from IFD0 may be wrong anyway)
        RawConv => q{
            if ($val[3] and $val[4] and $val[0] ne $val[3]) {
                my %val = (
                    0 => 'PreviewImageStart (1)',
                    1 => 'PreviewImageLength (1)',
                    2 => 'PreviewImageValid',
                );
                $self->FoundTag($tagInfo, \%val);
            }
            return undef if defined $val[2] and not $val[2];
            @grps = $self->GetGroup($$val{0});
            return Image::ExifTool::Exif::ExtractImage($self,$val[0],$val[1],'PreviewImage');
        },
    },
    JpgFromRaw => {
        Groups => { 0 => 'EXIF', 1 => 'SubIFD', 2 => 'Preview' },
        Writable => 1,
        WriteGroup => 'All',
        WriteCheck => '$self->CheckImage(\$val)',
        # Note: ExifTool 10.38 had disabled the ability to delete this -- why?
        # --> added the DelCheck in 10.61 to re-enable this
        DelCheck => '$val = ""; return undef', # can't delete, so set to empty string
        WriteAlso => {
            JpgFromRawStart  => 'defined $val ? 0xfeedfeed : undef',
            JpgFromRawLength => 'defined $val ? 0xfeedfeed : undef',
        },
        Require => {
            0 => 'JpgFromRawStart',
            1 => 'JpgFromRawLength',
        },
        Notes => q{
            this tag is writable, and may be used to update existing embedded images,
            but not create or delete them
        },
        RawConv => q{
            @grps = $self->GetGroup($$val{0});
            return Image::ExifTool::Exif::ExtractImage($self,$val[0],$val[1],"JpgFromRaw");
        },
    },
    OtherImage => {
        Groups => { 0 => 'EXIF', 1 => 'SubIFD', 2 => 'Preview' },
        Writable => 1,
        WriteGroup => 'All',
        WriteCheck => '$self->CheckImage(\$val)',
        DelCheck => '$val = ""; return undef', # can't delete, so set to empty string
        WriteAlso => {
            OtherImageStart  => 'defined $val ? 0xfeedfeed : undef',
            OtherImageLength => 'defined $val ? 0xfeedfeed : undef',
        },
        Require => {
            0 => 'OtherImageStart',
            1 => 'OtherImageLength',
        },
        Notes => q{
            this tag is writable, and may be used to update existing embedded images,
            but not create or delete them
        },
        # retrieve the thumbnail from our EXIF data
        RawConv => q{
            @grps = $self->GetGroup($$val{0});
            Image::ExifTool::Exif::ExtractImage($self,$val[0],$val[1],"OtherImage");
        },
    },
    PreviewImageSize => {
        Require => {
            0 => 'PreviewImageWidth',
            1 => 'PreviewImageHeight',
        },
        ValueConv => '"$val[0]x$val[1]"',
    },
    SubSecDateTimeOriginal => {
        Description => 'Date/Time Original',
        Groups => { 2 => 'Time' },
        Writable => 1,
        Shift => 0, # don't shift this tag
        Require => {
            0 => 'EXIF:DateTimeOriginal',
        },
        Desire => {
            1 => 'SubSecTimeOriginal',
            2 => 'OffsetTimeOriginal',
        },
        WriteAlso => {
            'EXIF:DateTimeOriginal' => '($val and $val=~/^(\d{4}:\d{2}:\d{2} \d{2}:\d{2}:\d{2})/) ? $1 : undef',
            'EXIF:SubSecTimeOriginal' => '($val and $val=~/\.(\d+)/) ? $1 : undef',
            'EXIF:OffsetTimeOriginal' => '($val and $val=~/([-+]\d{2}:\d{2}|Z)$/) ? ($1 eq "Z" ? "+00:00" : $1) : undef',
        },
        %subSecConv,
    },
    SubSecCreateDate => {
        Description => 'Create Date',
        Groups => { 2 => 'Time' },
        Writable => 1,
        Shift => 0, # don't shift this tag
        Require => {
            0 => 'EXIF:CreateDate',
        },
        Desire => {
            1 => 'SubSecTimeDigitized',
            2 => 'OffsetTimeDigitized',
        },
        WriteAlso => {
            'EXIF:CreateDate' => '($val and $val=~/^(\d{4}:\d{2}:\d{2} \d{2}:\d{2}:\d{2})/) ? $1 : undef',
            'EXIF:SubSecTimeDigitized' => '($val and $val=~/\.(\d+)/) ? $1 : undef',
            'EXIF:OffsetTimeDigitized' => '($val and $val=~/([-+]\d{2}:\d{2}|Z)$/) ? ($1 eq "Z" ? "+00:00" : $1) : undef',
        },
        %subSecConv,
    },
    SubSecModifyDate => {
        Description => 'Modify Date',
        Groups => { 2 => 'Time' },
        Writable => 1,
        Shift => 0, # don't shift this tag
        Require => {
            0 => 'EXIF:ModifyDate',
        },
        Desire => {
            1 => 'SubSecTime',
            2 => 'OffsetTime',
        },
        WriteAlso => {
            'EXIF:ModifyDate' => '($val and $val=~/^(\d{4}:\d{2}:\d{2} \d{2}:\d{2}:\d{2})/) ? $1 : undef',
            'EXIF:SubSecTime' => '($val and $val=~/\.(\d+)/) ? $1 : undef',
            'EXIF:OffsetTime' => '($val and $val=~/([-+]\d{2}:\d{2}|Z)$/) ? ($1 eq "Z" ? "+00:00" : $1) : undef',
        },
        %subSecConv,
    },
    CFAPattern => {
        Require => {
            0 => 'CFARepeatPatternDim',
            1 => 'CFAPattern2',
        },
        # generate CFAPattern
        ValueConv => q{
            my @a = split / /, $val[0];
            my @b = split / /, $val[1];
            return '?' unless @a==2 and @b==$a[0]*$a[1];
            return "$a[0] $a[1] @b";
        },
        PrintConv => 'Image::ExifTool::Exif::PrintCFAPattern($val)',
    },
    RedBalance => {
        Groups => { 2 => 'Camera' },
        Desire => {
            0 => 'WB_RGGBLevels',
            1 => 'WB_RGBGLevels',
            2 => 'WB_RBGGLevels',
            3 => 'WB_GRBGLevels',
            4 => 'WB_GRGBLevels',
            5 => 'WB_GBRGLevels',
            6 => 'WB_RGBLevels',
            7 => 'WB_GRBLevels',
            8 => 'WB_RBLevels',
            9 => 'WBRedLevel', # red
           10 => 'WBGreenLevel',
        },
        ValueConv => 'Image::ExifTool::Exif::RedBlueBalance(0,@val)',
        PrintConv => 'int($val * 1e6 + 0.5) * 1e-6',
    },
    BlueBalance => {
        Groups => { 2 => 'Camera' },
        Desire => {
            0 => 'WB_RGGBLevels',
            1 => 'WB_RGBGLevels',
            2 => 'WB_RBGGLevels',
            3 => 'WB_GRBGLevels',
            4 => 'WB_GRGBLevels',
            5 => 'WB_GBRGLevels',
            6 => 'WB_RGBLevels',
            7 => 'WB_GRBLevels',
            8 => 'WB_RBLevels',
            9 => 'WBBlueLevel', # blue
           10 => 'WBGreenLevel',
        },
        ValueConv => 'Image::ExifTool::Exif::RedBlueBalance(1,@val)',
        PrintConv => 'int($val * 1e6 + 0.5) * 1e-6',
    },
    GPSPosition => {
        Groups => { 2 => 'Location' },
        Require => {
            0 => 'GPSLatitude',
            1 => 'GPSLongitude',
        },
        Priority => 0,
        ValueConv => '(length($val[0]) or length($val[1])) ? "$val[0] $val[1]" : undef',
        PrintConv => '"$prt[0], $prt[1]"',
    },
    LensID => {
        Groups => { 2 => 'Camera' },
        Require => 'LensType',
        Desire => {
            1 => 'FocalLength',
            2 => 'MaxAperture',
            3 => 'MaxApertureValue',
            4 => 'MinFocalLength',
            5 => 'MaxFocalLength',
            6 => 'LensModel',
            7 => 'LensFocalRange',
            8 => 'LensSpec',
            9 => 'LensType2',
            10 => 'LensFocalLength', # (for Pentax to check for converter)
        },
        Notes => q{
            attempt to identify the actual lens from all lenses with a given LensType.
            Applies only to LensType values with a lookup table.  May be configured
            by adding user-defined lenses
        },
        # this LensID is only valid if the LensType has a PrintConv or is a model name
        RawConv => q{
            my $printConv = $$self{TAG_INFO}{LensType}{PrintConv};
            return $val if ref $printConv eq 'HASH' or (ref $printConv eq 'ARRAY' and
                ref $$printConv[0] eq 'HASH') or $val[0] =~ /(mm|\d\/F)/;
            return undef;
        },
        ValueConv => '$val',
        PrintConv => q{
            my $pcv;
            # use LensType2 instead of LensType if available and valid (Sony E-mount lenses)
            if ($val[9] and $val[9] & 0x8000) {
                $val[0] = $val[9];
                $prt[0] = $prt[9];
                $pcv = $$self{TAG_INFO}{LensType2}{PrintConv};
            }
            my $lens = Image::ExifTool::Exif::PrintLensID($self, $prt[0], $pcv, $prt[8], @val);
            # check for use of lens converter (Pentax K-3)
            if ($val[10] and $val[1] and $lens) {
                my $conv = $val[1] / $val[10];
                $lens .= sprintf(' + %.1fx converter', $conv) if $conv > 1.1;
            }
            return $lens;
        },
    },
);

# table for unknown IFD entries
%Image::ExifTool::Exif::Unknown = (
    GROUPS => { 0 => 'EXIF', 1 => 'UnknownIFD', 2 => 'Image'},
    WRITE_PROC => \&WriteExif,
);

# add our composite tags
Image::ExifTool::AddCompositeTags('Image::ExifTool::Exif');


#------------------------------------------------------------------------------
# AutoLoad our writer routines when necessary
#
sub AUTOLOAD
{
    return Image::ExifTool::DoAutoLoad($AUTOLOAD, @_);
}

#------------------------------------------------------------------------------
# Identify RAW file type for some TIFF-based formats using Compression value
# Inputs: 0) ExifTool object reference, 1) Compression value
# - sets TIFF_TYPE and FileType if identified
sub IdentifyRawFile($$)
{
    my ($et, $comp) = @_;
    if ($$et{FILE_TYPE} eq 'TIFF' and not $$et{IdentifiedRawFile}) {
        if ($compression{$comp} and $compression{$comp} =~ /^\w+ ([A-Z]{3}) Compressed$/) {
            $et->OverrideFileType($$et{TIFF_TYPE} = $1);
            $$et{IdentifiedRawFile} = 1;
        }
    }
}

#------------------------------------------------------------------------------
# Calculate LV (Light Value)
# Inputs: 0) Aperture, 1) ShutterSpeed, 2) ISO
# Returns: LV value (and converts input values to floating point if necessary)
sub CalculateLV($$$)
{
    local $_;
    # do validity checks on arguments
    return undef unless @_ >= 3;
    foreach (@_) {
        return undef unless $_ and /([+-]?(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?)/ and $1 > 0;
        $_ = $1;    # extract float from any other garbage
    }
    # (A light value of 0 is defined as f/1.0 at 1 second with ISO 100)
    return log($_[0] * $_[0] * 100 / ($_[1] * $_[2])) / log(2);
}

#------------------------------------------------------------------------------
# Calculate scale factor for 35mm effective focal length (ref 26/PH)
# Inputs: 0) ExifTool object ref
#         1) Focal length
#         2) Focal length in 35mm format
#         3) Canon digital zoom factor
#         4) Focal plane diagonal size (in mm)
#         5) Sensor size (X and Y in mm)
#         6/7) Focal plane X/Y size (in mm)
#         8) focal plane resolution units (1=None,2=inches,3=cm,4=mm,5=um)
#         9/10) Focal plane X/Y resolution
#         11/12,13/14...) Image width/height in order of precedence (first valid pair is used)
# Returns: 35mm conversion factor (or undefined if it can't be calculated)
sub CalcScaleFactor35efl
{
    my $et = shift;
    my $res = $_[7];    # save resolution units (in case they have been converted to string)
    my $sensXY = $_[4];
    Image::ExifTool::ToFloat(@_);
    my $focal = shift;
    my $foc35 = shift;

    return $foc35 / $focal if $focal and $foc35;

    my $digz = shift || 1;
    my $diag = shift;
    my $sens = shift;
    # calculate Canon sensor size using a dedicated algorithm
    if ($$et{Make} eq 'Canon') {
        require Image::ExifTool::Canon;
        my $canonDiag = Image::ExifTool::Canon::CalcSensorDiag(
            $$et{RATIONAL}{FocalPlaneXResolution},
            $$et{RATIONAL}{FocalPlaneYResolution},
        );
        $diag = $canonDiag if $canonDiag;
    }
    unless ($diag and Image::ExifTool::IsFloat($diag)) {
        if ($sens and $sensXY =~ / (\d+(\.?\d*)?)$/) {
            $diag = sqrt($sens * $sens + $1 * $1);
        } else {
            undef $diag;
            my $xsize = shift;
            my $ysize = shift;
            if ($xsize and $ysize) {
                # validate by checking aspect ratio because FocalPlaneX/YSize is not reliable
                my $a = $xsize / $ysize;
                if (abs($a-1.3333) < .1 or abs($a-1.5) < .1) {
                    $diag = sqrt($xsize * $xsize + $ysize * $ysize);
                }
            }
        }
        unless ($diag) {
            # get number of mm in units (assume inches unless otherwise specified)
            my %lkup = ( 3=>10, 4=>1, 5=>0.001 , cm=>10, mm=>1, um=>0.001 );
            my $units = $lkup{ shift() || $res || '' } || 25.4;
            my $x_res = shift || return undef;
            my $y_res = shift || $x_res;
            Image::ExifTool::IsFloat($x_res) and $x_res != 0 or return undef;
            Image::ExifTool::IsFloat($y_res) and $y_res != 0 or return undef;
            my ($w, $h);
            for (;;) {
                @_ < 2 and return undef;
                $w = shift;
                $h = shift;
                next unless $w and $h;
                my $a = $w / $h;
                last if $a > 0.5 and $a < 2; # stop if we get a reasonable value
            }
            # calculate focal plane size in mm
            $w *= $units / $x_res;
            $h *= $units / $y_res;
            $diag = sqrt($w*$w+$h*$h);
            # make sure size is reasonable
            return undef unless $diag > 1 and $diag < 100;
        }
    }
    return sqrt(36*36+24*24) * $digz / $diag;
}

#------------------------------------------------------------------------------
# Print exposure compensation fraction
sub PrintFraction($)
{
    my $val = shift;
    my $str;
    if (defined $val) {
        $val *= 1.00001;    # avoid round-off errors
        if (not $val) {
            $str = '0';
        } elsif (int($val)/$val > 0.999) {
            $str = sprintf("%+d", int($val));
        } elsif ((int($val*2))/($val*2) > 0.999) {
            $str = sprintf("%+d/2", int($val * 2));
        } elsif ((int($val*3))/($val*3) > 0.999) {
            $str = sprintf("%+d/3", int($val * 3));
        } else {
            $str = sprintf("%+.3g", $val);
        }
    }
    return $str;
}

#------------------------------------------------------------------------------
# Convert fraction or number to floating point value (or 'undef' or 'inf')
sub ConvertFraction($)
{
    my $val = shift;
    if ($val =~ m{([-+]?\d+)/(\d+)}) {
        $val = $2 ? $1 / $2 : ($1 ? 'inf' : 'undef');
    }
    return $val;
}

#------------------------------------------------------------------------------
# Convert EXIF text to something readable
# Inputs: 0) ExifTool object reference, 1) EXIF text,
#         2) [optional] 1 to apply CharsetEXIF to ASCII text,
#         3) tag name for warning message (may be argument 2)
# Returns: text encoded according to Charset option (with trailing spaces removed)
sub ConvertExifText($$;$$)
{
    my ($et, $val, $asciiFlex, $tag) = @_;
    return $val if length($val) < 8;
    my $id = substr($val, 0, 8);
    my $str = substr($val, 8);
    my $type;

    delete $$et{WrongByteOrder};
    if ($$et{OPTIONS}{Validate} and $id =~ /^(ASCII|UNICODE|JIS)?\0* \0*$/) {
        $et->Warn(($1 || 'Undefined') . ' text header' . ($tag ? " for $tag" : '') . ' has spaces instead of nulls');
    }
    # Note: allow spaces instead of nulls in the ID codes because
    # it is fairly common for camera manufacturers to get this wrong
    # (also handle Canon ZoomBrowser EX 4.5 null followed by 7 bytes of garbage)
    if ($id =~ /^(ASCII)?(\0|[\0 ]+$)/) {
        # truncate at null terminator (shouldn't have a null based on the
        # EXIF spec, but it seems that few people actually read the spec)
        $str =~ s/\0.*//s;
        # allow ASCII text to contain any other specified encoding
        if ($asciiFlex and $asciiFlex eq '1') {
            my $enc = $et->Options('CharsetEXIF');
            $str = $et->Decode($str, $enc) if $enc;
        }
    # by the EXIF spec, the following string should be "UNICODE\0", but
    # apparently Kodak sometimes uses "Unicode\0" in the APP3 "Meta" information.
    # However, unfortunately Ricoh uses "Unicode\0" in the RR30 EXIF UserComment
    # when the text is actually ASCII, so only recognize uppercase "UNICODE\0".
    } elsif ($id =~ /^(UNICODE)[\0 ]$/) {
        $type = $1;
        # MicrosoftPhoto writes as little-endian even in big-endian EXIF,
        # so we must guess at the true byte ordering
        $str = $et->Decode($str, 'UTF16', 'Unknown');
    } elsif ($id =~ /^(JIS)[\0 ]{5}$/) {
        $type = $1;
        $str = $et->Decode($str, 'JIS', 'Unknown');
    } else {
        $tag = $asciiFlex if $asciiFlex and $asciiFlex ne 1;
        $et->Warn('Invalid EXIF text encoding' . ($tag ? " for $tag" : ''));
        $str = $id . $str;
    }
    if ($$et{WrongByteOrder} and $$et{OPTIONS}{Validate}) {
        $et->Warn('Wrong byte order for EXIF' . ($tag ? " $tag" : '') .
                  ($type ? " $type" : '') . ' text');
    }
    $str =~ s/ +$//;    # trim trailing blanks
    return $str;
}

#------------------------------------------------------------------------------
# Print conversion for SpatialFrequencyResponse
sub PrintSFR($)
{
    my $val = shift;
    return $val unless length $val > 4;
    my ($n, $m) = (Get16u(\$val, 0), Get16u(\$val, 2));
    my @cols = split /\0/, substr($val, 4), $n+1;
    my $pos = length($val) - 8 * $n * $m;
    return $val unless @cols == $n+1 and $pos >= 4;
    pop @cols;
    my ($i, $j);
    for ($i=0; $i<$n; ++$i) {
        my @rows;
        for ($j=0; $j<$m; ++$j) {
            push @rows, Image::ExifTool::GetRational64u(\$val, $pos + 8*($i+$j*$n));
        }
        $cols[$i] .= '=' . join(',',@rows) . '';
    }
    return join '; ', @cols;
}

#------------------------------------------------------------------------------
# Print numerical parameter value (with sign, or 'Normal' for zero)
# Inputs: 0) value, 1) flag for inverse conversion, 2) conversion hash reference
sub PrintParameter($$$)
{
    my ($val, $inv, $conv) = @_;
    return $val if $inv;
    if ($val > 0) {
        if ($val > 0xfff0) {    # a negative value in disguise?
            $val = $val - 0x10000;
        } else {
            $val = "+$val";
        }
    }
    return $val;
}

#------------------------------------------------------------------------------
# Convert parameter back to standard EXIF value
#   0,0.00,etc or "Normal" => 0
#   -1,-2,etc or "Soft" or "Low" => 1
#   +1,+2,1,2,etc or "Hard" or "High" => 2
sub ConvertParameter($)
{
    my $val = shift;
    my $isFloat = Image::ExifTool::IsFloat($val);
    # normal is a value of zero
    return 0 if $val =~ /\bn/i or ($isFloat and $val == 0);
    # "soft", "low" or any negative number is a value of 1
    return 1 if $val =~ /\b(s|l)/i or ($isFloat and $val < 0);
    # "hard", "high" or any positive number is a value of 2
    return 2 if $val =~ /\bh/i or $isFloat;
    return undef;
}

#------------------------------------------------------------------------------
# Calculate Red/BlueBalance
# Inputs: 0) 0=red, 1=blue, 1-8) WB_RGGB/RGBG/RBGG/GRBG/GRGB/RGB/GRB/RBLevels,
#         8) red or blue level, 9) green level
my @rggbLookup = (
    # indices for R, G, G and B components in input value
    [ 0, 1, 2, 3 ], # 0 RGGB
    [ 0, 1, 3, 2 ], # 1 RGBG
    [ 0, 2, 3, 1 ], # 2 RBGG
    [ 1, 0, 3, 2 ], # 3 GRBG
    [ 1, 0, 2, 3 ], # 4 GRGB
    [ 2, 3, 0, 1 ], # 5 GBRG
    [ 0, 1, 1, 2 ], # 6 RGB
    [ 1, 0, 0, 2 ], # 7 GRB
    [ 0, 256, 256, 1 ], # 8 RB (green level is 256)
);
sub RedBlueBalance($@)
{
    my $blue = shift;
    my ($i, $val, $levels);
    for ($i=0; $i<@rggbLookup; ++$i) {
        $levels = shift or next;
        my @levels = split ' ', $levels;
        next if @levels < 2;
        my $lookup = $rggbLookup[$i];
        my $g = $$lookup[1];    # get green level or index
        if ($g < 4) {
            next if @levels < 3;
            $g = ($levels[$g] + $levels[$$lookup[2]]) / 2 or next;
        } elsif ($levels[$$lookup[$blue * 3]] < 4) {
            $g = 1; # Some Nikon cameras use a scaling factor of 1 (E5700)
        }
        $val = $levels[$$lookup[$blue * 3]] / $g;
        last;
    }
    $val = $_[0] / $_[1] if not defined $val and ($_[0] and $_[1]);
    return $val;
}

#------------------------------------------------------------------------------
# Print exposure time as a fraction
sub PrintExposureTime($)
{
    my $secs = shift;
    if ($secs < 0.25001 and $secs > 0) {
        return sprintf("1/%d",int(0.5 + 1/$secs));
    }
    $_ = sprintf("%.1f",$secs);
    s/\.0$//;
    return $_;
}

#------------------------------------------------------------------------------
# Print FNumber
sub PrintFNumber($)
{
    my $val = shift;
    if (Image::ExifTool::IsFloat($val) and $val > 0) {
        # round to 1 decimal place, or 2 for values < 1.0
        $val = sprintf(($val<1 ? "%.2f" : "%.1f"), $val);
    }
    return $val;
}

#------------------------------------------------------------------------------
# Decode raw CFAPattern value
# Inputs: 0) ExifTool ref, 1) binary value
# Returns: string of numbers
sub DecodeCFAPattern($$)
{
    my ($self, $val) = @_;
    # some panasonic cameras (SV-AS3, SV-AS30) write this in ascii (very odd)
    if ($val =~ /^[0-6]+$/) {
        $self->Warn('Incorrectly formatted CFAPattern', 1);
        $val =~ tr/0-6/\x00-\x06/;
    }
    return $val unless length($val) >= 4;
    my @a = unpack(GetByteOrder() eq 'II' ? 'v2C*' : 'n2C*', $val);
    my $end = 2 + $a[0] * $a[1];
    if ($end > @a) {
        # try swapping byte order (I have seen this order different than in EXIF)
        my ($x, $y) = unpack('n2',pack('v2',$a[0],$a[1]));
        if (@a < 2 + $x * $y) {
            $self->Warn('Invalid CFAPattern', 1);
        } else {
            ($a[0], $a[1]) = ($x, $y);
            # (can't technically be wrong because the order isn't well defined by the EXIF spec)
            # $self->Warn('Wrong byte order for CFAPattern');
        }
    }
    return "@a";
}

#------------------------------------------------------------------------------
# Print CFA Pattern
sub PrintCFAPattern($)
{
    my $val = shift;
    my @a = split ' ', $val;
    return '<truncated data>' unless @a >= 2;
    return '<zero pattern size>' unless $a[0] and $a[1];
    my $end = 2 + $a[0] * $a[1];
    return '<invalid pattern size>' if $end > @a;
    my @cfaColor = qw(Red Green Blue Cyan Magenta Yellow White);
    my ($pos, $rtnVal) = (2, '[');
    for (;;) {
        $rtnVal .= $cfaColor[$a[$pos]] || 'Unknown';
        last if ++$pos >= $end;
        ($pos - 2) % $a[1] and $rtnVal .= ',', next;
        $rtnVal .= '][';
    }
    return $rtnVal . ']';
}

#------------------------------------------------------------------------------
# Print conversion for lens info
# Inputs: 0) string of values (min focal, max focal, min F, max F)
# Returns: string in the form "12-20mm f/3.8-4.5" or "50mm f/1.4"
sub PrintLensInfo($)
{
    my $val = shift;
    my @vals = split ' ', $val;
    return $val unless @vals == 4;
    my $c = 0;
    foreach (@vals) {
        Image::ExifTool::IsFloat($_) and ++$c, next;
        $_ eq 'inf' and $_ = '?', ++$c, next;
        $_ eq 'undef' and $_ = '?', ++$c, next;
    }
    return $val unless $c == 4;
    $val = $vals[0];
    # (the Pentax Q writes zero for upper value of fixed-focal-length lenses)
    $val .= "-$vals[1]" if $vals[1] and $vals[1] ne $vals[0];
    $val .= "mm f/$vals[2]";
    $val .= "-$vals[3]" if $vals[3] and $vals[3] ne $vals[2];
    return $val;
}

#------------------------------------------------------------------------------
# Get lens info from lens model string
# Inputs: 0) lens string, 1) flag to allow unknown "?" values
# Returns: 0) min focal, 1) max focal, 2) min aperture, 3) max aperture
# Notes: returns empty list if lens string could not be parsed
sub GetLensInfo($;$)
{
    my ($lens, $unk) = @_;
    # extract focal length and aperture ranges for this lens
    my $pat = '\\d+(?:\\.\\d+)?';
    $pat .= '|\\?' if $unk;
    return () unless $lens =~ /($pat)(?:-($pat))?\s*mm.*?(?:[fF]\/?\s*)($pat)(?:-($pat))?/;
    # ($1=short focal, $2=long focal, $3=max aperture wide, $4=max aperture tele)
    my @a = ($1, $2, $3, $4);
    $a[1] or $a[1] = $a[0];
    $a[3] or $a[3] = $a[2];
    if ($unk) {
        local $_;
        $_ eq '?' and $_ = 'undef' foreach @a;
    }
    return @a;
}

#------------------------------------------------------------------------------
# Attempt to identify the specific lens if multiple lenses have the same LensType
# Inputs: 0) ExifTool object ref, 1) LensType print value, 2) PrintConv hash ref,
#         3) LensSpec print value, 4) LensType numerical value, 5) FocalLength,
#         6) MaxAperture, 7) MaxApertureValue, 8) MinFocalLength, 9) MaxFocalLength,
#         10) LensModel, 11) LensFocalRange, 12) LensSpec
sub PrintLensID($$@)
{
    my ($et, $lensTypePrt, $printConv, $lensSpecPrt, $lensType, $focalLength,
        $maxAperture, $maxApertureValue, $shortFocal, $longFocal, $lensModel,
        $lensFocalRange, $lensSpec) = @_;
    # this logic relies on the LensType lookup:
    return undef unless defined $lensType;
    # get print conversion hash if necessary
    $printConv or $printConv = $$et{TAG_INFO}{LensType}{PrintConv};
    # just copy LensType PrintConv value if it was a lens name
    # (Olympus or Panasonic -- just exclude things like Nikon and Leaf LensType)
    unless (ref $printConv eq 'HASH') {
        if (ref $printConv eq 'ARRAY' and ref $$printConv[0] eq 'HASH') {
            $printConv = $$printConv[0];
            $lensTypePrt =~ s/;.*//;
            $lensType =~ s/ .*//;
        } else {
            return $lensTypePrt if $lensTypePrt =~ /mm/;
            return $lensTypePrt if $lensTypePrt =~ s/(\d)\/F/$1mm F/;
            return undef;
        }
    }
    # get LensSpec information if available (Sony)
    my ($sf0, $lf0, $sa0, $la0);
    if ($lensSpecPrt) {
        ($sf0, $lf0, $sa0, $la0) = GetLensInfo($lensSpecPrt);
        undef $sf0 unless $sa0; # (make sure aperture isn't zero)
    }
    # use MaxApertureValue if MaxAperture is not available
    $maxAperture = $maxApertureValue unless $maxAperture;
    if ($lensFocalRange and $lensFocalRange =~ /^(\d+)(?: (?:to )?(\d+))?$/) {
        ($shortFocal, $longFocal) = ($1, $2 || $1);
    }
    if ($$et{Make} eq 'SONY') {
        # Patch for Metabones or other adapters on Sony E-mount cameras (ref Jos Roost)
        # Metabones Canon EF to E-mount adapters add 0xef00, 0xbc00 or 0x7700 to the
        # high byte for 2-byte Canon LensType values, so we need to adjust for these.
        # Offset 0xef00 is also used by Sigma MC-11, Fotodiox and Viltrox EF-E adapters.
        # Have to exclude A-mount Sigma Filtermatic with 'odd' LensType=0xff00.
        if ($lensType != 0xffff and $lensType != 0xff00) {
            require Image::ExifTool::Minolta;
            if ($Image::ExifTool::Minolta::metabonesID{$lensType & 0xff00}) {
                $lensType -= ($lensType >= 0xef00 ? 0xef00 : $lensType >= 0xbc00 ? 0xbc00 : 0x7700);
                require Image::ExifTool::Canon;
                $printConv = \%Image::ExifTool::Canon::canonLensTypes;
                $lensTypePrt = $$printConv{$lensType} if $$printConv{$lensType};
            # Test for Sigma MC-11 SA-E adapter with Sigma SA lens using 0x4900 offset.
            # (upper limit of test cuts off two highest Sigma lenses, but prevents
            # conflict with old Minolta 25xxx and higher ID's)
            } elsif ($lensType >= 0x4900 and $lensType <= 0x590a) {
                require Image::ExifTool::Sigma;
                $lensType -= 0x4900;
                $printConv = \%Image::ExifTool::Sigma::sigmaLensTypes;
                $lensTypePrt = $$printConv{$lensType} if $$printConv{$lensType};
            }
        }
    } elsif ($shortFocal and $longFocal) {
        # Canon (and some other makes) include makernote information
        # which allows better lens identification
        require Image::ExifTool::Canon;
        return Image::ExifTool::Canon::PrintLensID($printConv, $lensType,
                    $shortFocal, $longFocal, $maxAperture, $lensModel);
    }
    my $lens = $$printConv{$lensType};
    return ($lensModel || $lensTypePrt) unless $lens;
    return $lens unless $$printConv{"$lensType.1"};
    $lens =~ s/ or .*//s;    # remove everything after "or"
    # make list of all possible matching lenses
    my @lenses = ( $lens );
    my $i;
    for ($i=1; $$printConv{"$lensType.$i"}; ++$i) {
        push @lenses, $$printConv{"$lensType.$i"};
    }
    # attempt to determine actual lens
    my (@matches, @best, @user, $diff);
    foreach $lens (@lenses) {
        push @user, $lens if $Image::ExifTool::userLens{$lens};
        # sf = short focal
        # lf = long focal
        # sa = max aperture at short focal
        # la = max aperture at long focal
        my ($sf, $lf, $sa, $la) = GetLensInfo($lens);
        next unless $sf;
        # check against LensSpec parameters if available
        if ($sf0) {
            next if abs($sf - $sf0) > 0.5 or abs($sa - $sa0) > 0.15 or
                    abs($lf - $lf0) > 0.5 or abs($la - $la0) > 0.15;
            # the basic parameters match, but also check against additional lens features:
            # for Sony A and E lenses, the full LensSpec string should match with end of LensType,
            # excluding any part between () at the end, and preceded by a space (the space
            # ensures that e.g. Zeiss Loxia 21mm having LensSpec "E 21mm F2.8" will not be
            # identified as "Sony FE 21mm F2.8 (SEL28F20 + SEL075UWC)")
            $lensSpecPrt and $lens =~ / \Q$lensSpecPrt\E( \(|$)/ and @best = ( $lens ), last;
            # exactly-matching Sony lens should have been found above, so only add non-Sony lenses
            push @best, $lens unless $lens =~ /^Sony /;
            next;
        }
        # adjust focal length and aperture if teleconverter is attached (Minolta)
        if ($lens =~ / \+ .*? (\d+(\.\d+)?)x( |$)/) {
            $sf *= $1;  $lf *= $1;
            $sa *= $1;  $la *= $1;
        }
        # see if we can rule out this lens using FocalLength and MaxAperture
        if ($focalLength) {
            next if $focalLength < $sf - 0.5;
            next if $focalLength > $lf + 0.5;
        }
        if ($maxAperture) {
            # it seems that most manufacturers set MaxAperture and MaxApertureValue
            # to the maximum aperture (smallest F number) for the current focal length
            # of the lens, so assume that MaxAperture varies with focal length and find
            # the closest match (this is somewhat contrary to the EXIF specification which
            # states "The smallest F number of the lens", without mention of focal length)
            next if $maxAperture < $sa - 0.15;  # (0.15 is arbitrary)
            next if $maxAperture > $la + 0.15;
            # now determine the best match for this aperture
            my $aa; # approximate maximum aperture at this focal length
            if ($sf == $lf or $sa == $la or $focalLength <= $sf) {
                # either 1) prime lens, 2) fixed-aperture zoom, or 3) zoom at min focal
                $aa = $sa;
            } elsif ($focalLength >= $lf) {
                $aa = $la;
            } else {
                # assume a log-log variation of max aperture with focal length
                # (see http://regex.info/blog/2006-10-05/263)
                $aa = exp(log($sa) + (log($la)-log($sa)) / (log($lf)-log($sf)) *
                                     (log($focalLength)-log($sf)));
                # a linear relationship between 1/FocalLength and 1/MaxAperture fits Sony better (ref 27)
                #$aa = 1 / (1/$sa + (1/$focalLength - 1/$sf) * (1/$la - 1/$sa) / (1/$lf - 1/$sf));
            }
            my $d = abs($maxAperture - $aa);
            if (defined $diff) {
                $d > $diff + 0.15 and next;     # (0.15 is arbitrary)
                $d < $diff - 0.15 and undef @best;
            }
            $diff = $d;
            push @best, $lens;
        }
        push @matches, $lens;
    }
    # return the user-defined lens if it exists
    if (@user) {
        # choose the best match if we have more than one
        if (@user > 1) {
            my ($try, @good);
            foreach $try (\@best, \@matches) {
                $Image::ExifTool::userLens{$_} and push @good, $_ foreach @$try;
                return join(' or ', @good) if @good;
            }
        }
        return join(' or ', @user);
    }
    # return the best match(es) from the possible lenses
    return join(' or ', @best) if @best;
    return join(' or ', @matches) if @matches;
    $lens = $$printConv{$lensType};
    return $lensModel if $lensModel and $lens =~ / or /; # (eg. Sony NEX-5N)
    return $lens;
}

#------------------------------------------------------------------------------
# Translate date into standard EXIF format
# Inputs: 0) date
# Returns: date in format '2003:10:22'
# - bad formats recognized: '2003-10-22','2003/10/22','2003 10 22','20031022'
# - removes null terminator if it exists
sub ExifDate($)
{
    my $date = shift;
    $date =~ s/\0$//;       # remove any null terminator
    # separate year:month:day with colons
    # (have seen many other characters, including nulls, used erroneously)
    $date =~ s/(\d{4})[^\d]*(\d{2})[^\d]*(\d{2})$/$1:$2:$3/;
    return $date;
}

#------------------------------------------------------------------------------
# Translate time into standard EXIF format
# Inputs: 0) time
# Returns: time in format '10:30:55'
# - bad formats recognized: '10 30 55', '103055', '103055+0500'
# - removes null terminator if it exists
# - leaves time zone intact if specified (eg. '10:30:55+05:00')
sub ExifTime($)
{
    my $time = shift;
    $time =~ tr/ /:/;   # use ':' (not ' ') as a separator
    $time =~ s/\0$//;   # remove any null terminator
    # add separators if they don't exist
    $time =~ s/^(\d{2})(\d{2})(\d{2})/$1:$2:$3/;
    $time =~ s/([+-]\d{2})(\d{2})\s*$/$1:$2/;   # to timezone too
    return $time;
}

#------------------------------------------------------------------------------
# Generate TIFF file from scratch (in current byte order)
# Inputs: 0) hash of IFD entries (TagID => Value; multiple values space-delimited)
#         1) raw image data reference
# Returns: TIFF image data, or undef on error
sub GenerateTIFF($$)
{
    my ($entries, $dataPt) = @_;
    my ($rtnVal, $tag, $offsetPos);

    my $num = scalar keys %$entries;
    my $ifdBuff = GetByteOrder() . Set16u(42) .  Set32u(8) .  Set16u($num);
    my $valBuff = '';
    my $tagTablePtr = GetTagTable('Image::ExifTool::Exif::Main');
    foreach $tag (sort { $a <=> $b } keys %$entries) {
        my $tagInfo = $$tagTablePtr{$tag};
        my $fmt = ref $tagInfo eq 'HASH' ? $$tagInfo{Writable} : 'int32u';
        return undef unless defined $fmt;
        my $val = Image::ExifTool::WriteValue($$entries{$tag}, $fmt, -1);
        return undef unless defined $val;
        my $format = $formatNumber{$fmt};
        $ifdBuff .= Set16u($tag) . Set16u($format) . Set32u(length($val)/$formatSize[$format]);
        $offsetPos = length($ifdBuff) if $tag == 0x111; # (remember StripOffsets position)
        if (length $val > 4) {
            $ifdBuff .= Set32u(10 + 12 * $num + 4 + length($valBuff));
            $valBuff .= $val;
        } else {
            $val .= "\0" x (4 - length($val)) if length $val < 4;
            $ifdBuff .= $val;
        }
    }
    $ifdBuff .= "\0\0\0\0"; # (no IFD1)
    return undef unless $offsetPos;
    Set32u(length($ifdBuff) + length($valBuff), \$ifdBuff, $offsetPos);
    return $ifdBuff . $valBuff . $$dataPt;
}

#------------------------------------------------------------------------------
# Rebuild TIFF thumbnail(s)/preview(s) into stand-alone files with current byte order
# Inputs: 0) ExifTool ref, 1) SubfileType, 2) Compression, 3) ImageWidth, 4) ImageHeight,
#         5) BitsPerSample, 6) PhotometricInterpretation, 7) StripOffsets, 8) SamplesPerPixel,
#         9) RowsPerStrip, 10) StripByteCounts, 10) PlanarConfiguration, 11) Orientation
# Returns: 0) TIFF image or undef, 1/2) Family 0/1 groups for TIFF preview IFD
sub RebuildTIFF($;@)
{
    local $_;
    my $et = $_[0];
    my $value = $$et{VALUE};
    my ($i, $j, $rtn, $grp0, $grp1);
    return undef if $$et{FILE_TYPE} eq 'RWZ';
SubFile:
    for ($i=0; ; ++$i) {
        my $key = 'SubfileType' . ($i ? " ($i)" : '');
        last unless defined $$value{$key};
        next unless $$value{$key} == 1; # (reduced-resolution image)
        my $grp = $et->GetGroup($key, 1);
        my $cmp = $et->FindValue('Compression', $grp);
        next unless $cmp == 1; # (no compression)
        my %vals = (Compression=>$cmp, PlanarConfiguration=>1, Orientation=>1);
        foreach (qw(ImageWidth ImageHeight BitsPerSample PhotometricInterpretation
                    StripOffsets SamplesPerPixel RowsPerStrip StripByteCounts
                    PlanarConfiguration Orientation))
        {
            my $val = $et->FindValue($_, $grp);
            defined $val and $vals{$_} = $val, next;
            next SubFile unless defined $vals{$_};
        }
        my ($w, $h) = @vals{'ImageWidth', 'ImageHeight'};
        my @bits = split ' ', $vals{BitsPerSample};
        my $rowBytes = 0;
        $rowBytes += $w * int(($_+7)/8) foreach @bits;
        my $dat = '';
        my @off = split ' ', $vals{StripOffsets};
        my @len = split ' ', $vals{StripByteCounts};
        # read the image data
        for ($j=0; $j<@off; ++$j) {
            next SubFile unless $len[$j] == $rowBytes * $vals{RowsPerStrip};
            my $tmp = $et->ExtractBinary($off[$j], $len[$j]);
            next SubFile unless defined $tmp;
            $dat .= $tmp;
        }
        # generate the TIFF image
        my %entries = (
            0x0fe => 0,                 # SubfileType = 0
            0x100 => $w,                # ImageWidth
            0x101 => $h,                # ImageHeight
            0x102 => $vals{BitsPerSample},# BitsPerSample
            0x103 => $vals{Compression},# Compression
            0x106 => $vals{PhotometricInterpretation}, # PhotometricInterpretation
            0x111 => 0,                 # StripOffsets (will be adjusted later)
            0x112 => $vals{Orientation},# Orientation
            0x115 => $vals{SamplesPerPixel}, # SamplesPerPixel
            0x116 => $h,                # RowsPerStrip
            0x117 => $h * $rowBytes,    # StripByteCounts
            0x11a => 72,                # XResolution = 72
            0x11b => 72,                # YResolution = 72
            0x11c => $vals{PlanarConfiguration}, # PlanarConfiguration
            0x128 => 2,                 # ResolutionUnit = 2
        );
        my $img = GenerateTIFF(\%entries, \$dat);

        if (not defined $img) {
            $et->Warn('Invalid ' . ($w > 256 ? 'Preview' : 'Thumbnail') . 'TIFF data');
        } elsif ($rtn or $w > 256) { # (call it a preview if larger than 256 pixels)
            $et->FoundTag('PreviewTIFF', \$img, $et->GetGroup($key));
        } else {
            $rtn = \$img;
            ($grp0, $grp1) = $et->GetGroup($key);
        }
    }
    return $rtn unless wantarray;
    return ($rtn, $grp0, $grp1);
}

#------------------------------------------------------------------------------
# Extract image from file
# Inputs: 0) ExifTool object reference, 1) data offset (in file), 2) data length
#         3) [optional] tag name
# Returns: Reference to Image if specifically requested or "Binary data" message
#          Returns undef if there was an error loading the image
sub ExtractImage($$$$)
{
    my ($et, $offset, $len, $tag) = @_;
    my $dataPt = \$$et{EXIF_DATA};
    my $dataPos = $$et{EXIF_POS};
    my $image;

    # no image if length is zero, and don't try to extract binary from XMP file
    return undef if not $len or $$et{FILE_TYPE} eq 'XMP';

    # take data from EXIF block if possible
    if (defined $dataPos and $offset>=$dataPos and $offset+$len<=$dataPos+length($$dataPt)) {
        $image = substr($$dataPt, $offset-$dataPos, $len);
    } else {
        $image = $et->ExtractBinary($offset, $len, $tag);
        return undef unless defined $image;
        # patch for incorrect ThumbnailOffset in some Sony DSLR-A100 ARW images
        if ($tag and $tag eq 'ThumbnailImage' and $$et{TIFF_TYPE} eq 'ARW' and
            $$et{Model} eq 'DSLR-A100' and $offset < 0x10000 and
            $image !~ /^(Binary data|\xff\xd8\xff)/)
        {
            my $try = $et->ExtractBinary($offset + 0x10000, $len, $tag);
            if (defined $try and $try =~ /^\xff\xd8\xff/) {
                $image = $try;
                $$et{VALUE}{ThumbnailOffset} += 0x10000;
                $et->Warn('Adjusted incorrect A100 ThumbnailOffset', 1);
            }
        }
    }
    return $et->ValidateImage(\$image, $tag);
}

#------------------------------------------------------------------------------
# Process EXIF directory
# Inputs: 0) ExifTool object reference
#         1) Reference to directory information hash
#         2) Pointer to tag table for this directory
# Returns: 1 on success, otherwise returns 0 and sets a Warning
sub ProcessExif($$$)
{
    my ($et, $dirInfo, $tagTablePtr) = @_;
    my $dataPt = $$dirInfo{DataPt};
    my $dataPos = $$dirInfo{DataPos} || 0;
    my $dataLen = $$dirInfo{DataLen};
    my $dirStart = $$dirInfo{DirStart} || 0;
    my $dirLen = $$dirInfo{DirLen} || $dataLen - $dirStart;
    my $dirName = $$dirInfo{DirName};
    my $base = $$dirInfo{Base} || 0;
    my $firstBase = $base;
    my $raf = $$dirInfo{RAF};
    my $verbose = $et->Options('Verbose');
    my $validate = $et->Options('Validate');
    my $htmlDump = $$et{HTML_DUMP};
    my $success = 1;
    my ($tagKey, $dirSize, $makerAddr, $strEnc, %offsetInfo);
    my $inMakerNotes = $$tagTablePtr{GROUPS}{0} eq 'MakerNotes';

    # set encoding to assume for strings
    $strEnc = $et->Options('CharsetEXIF') if $$tagTablePtr{GROUPS}{0} eq 'EXIF';

    # ignore non-standard EXIF while in strict MWG compatibility mode
    if (($validate or $Image::ExifTool::MWG::strict) and $dirName eq 'IFD0' and
        $tagTablePtr eq \%Image::ExifTool::Exif::Main and
        $$et{FILE_TYPE} =~ /^(JPEG|TIFF|PSD)$/)
    {
        my $path = $et->MetadataPath();
        unless ($path =~ /^(JPEG-APP1-IFD0|TIFF-IFD0|PSD-EXIFInfo-IFD0)$/) {
            if ($Image::ExifTool::MWG::strict) {
                $et->Warn("Ignored non-standard EXIF at $path");
                return 1;
            } else {
                $et->Warn("Non-standard EXIF at $path", 1);
            }
        }
    }
    # mix htmlDump and Validate into verbose so we can test for all at once
    $verbose = -1 if $htmlDump;
    $verbose = -2 if $validate and not $verbose;
    $dirName eq 'EXIF' and $dirName = $$dirInfo{DirName} = 'IFD0';
    $$dirInfo{Multi} = 1 if $dirName =~ /^(IFD0|SubIFD)$/ and not defined $$dirInfo{Multi};
    # get a more descriptive name for MakerNote sub-directories
    my $dir = $$dirInfo{Name};
    $dir = $dirName unless $dir and $inMakerNotes and $dir !~ /^MakerNote/;

    my ($numEntries, $dirEnd);
    if ($dirStart >= 0 and $dirStart <= $dataLen-2) {
        # make sure data is large enough (patches bug in Olympus subdirectory lengths)
        $numEntries = Get16u($dataPt, $dirStart);
        $dirSize = 2 + 12 * $numEntries;
        $dirEnd = $dirStart + $dirSize;
        if ($dirSize > $dirLen) {
            if (($verbose > 0 or $validate) and not $$dirInfo{SubIFD}) {
                my $short = $dirSize - $dirLen;
                $$et{INDENT} =~ s/..$//; # keep indent the same
                $et->Warn("Short directory size for $dir (missing $short bytes)");
                $$et{INDENT} .= '| ';
            }
            undef $dirSize if $dirEnd > $dataLen; # read from file if necessary
        }
    }
    # read IFD from file if necessary
    unless ($dirSize) {
        $success = 0;
        if ($raf) {
            # read the count of entries in this IFD
            my $offset = $dirStart + $dataPos;
            my ($buff, $buf2);
            if ($raf->Seek($offset + $base, 0) and $raf->Read($buff,2) == 2) {
                my $len = 12 * Get16u(\$buff,0);
                # also read next IFD pointer if available
                if ($raf->Read($buf2, $len+4) >= $len) {
                    $buff .= $buf2;
                    # make copy of dirInfo since we're going to modify it
                    my %newDirInfo = %$dirInfo;
                    $dirInfo = \%newDirInfo;
                    # update directory parameters for the newly loaded IFD
                    $dataPt = $$dirInfo{DataPt} = \$buff;
                    $dataPos = $$dirInfo{DataPos} = $offset;
                    $dataLen = $$dirInfo{DataLen} = length $buff;
                    $dirStart = $$dirInfo{DirStart} = 0;
                    $dirLen = $$dirInfo{DirLen} = length $buff;
                    $success = 1;
                }
            }
        }
        unless ($success) {
            $et->Warn("Bad $dir directory");
            return 0;
        }
        $numEntries = Get16u($dataPt, $dirStart);
        $dirSize = 2 + 12 * $numEntries;
        $dirEnd = $dirStart + $dirSize;
    }
    $verbose > 0 and $et->VerboseDir($dirName, $numEntries);
    my $bytesFromEnd = $dataLen - $dirEnd;
    if ($bytesFromEnd < 4) {
        unless ($bytesFromEnd==2 or $bytesFromEnd==0) {
            $et->Warn("Illegal $dir directory size ($numEntries entries)");
            return 0;
        }
    }
    # fix base offset for maker notes if necessary
    if (defined $$dirInfo{MakerNoteAddr}) {
        $makerAddr = $$dirInfo{MakerNoteAddr};
        delete $$dirInfo{MakerNoteAddr};
        if (Image::ExifTool::MakerNotes::FixBase($et, $dirInfo)) {
            $base = $$dirInfo{Base};
            $dataPos = $$dirInfo{DataPos};
        }
    }
    if ($htmlDump) {
        my $longName = $dir eq 'MakerNotes' ? ($$dirInfo{Name} || $dir) : $dir;
        if (defined $makerAddr) {
            my $hdrLen = $dirStart + $dataPos + $base - $makerAddr;
            $et->HDump($makerAddr, $hdrLen, "MakerNotes header", $longName) if $hdrLen > 0;
        }
        unless ($$dirInfo{NoDumpEntryCount}) {
            $et->HDump($dirStart + $dataPos + $base, 2, "$longName entries",
                       "Entry count: $numEntries");
        }
        my $tip;
        if ($bytesFromEnd >= 4) {
            my $nxt = ($dir =~ /^(.*?)(\d+)$/) ? $1 . ($2 + 1) : 'Next IFD';
            $tip = sprintf("$nxt offset: 0x%.4x", Get32u($dataPt, $dirEnd));
        }
        $et->HDump($dirEnd + $dataPos + $base, 4, "Next IFD", $tip, 0);
    }

    # patch for Canon EOS 40D firmware 1.0.4 bug (incorrect directory counts)
    # (must do this before parsing directory or CameraSettings offset will be suspicious)
    if ($inMakerNotes and $$et{Model} eq 'Canon EOS 40D' and $numEntries) {
        my $entry = $dirStart + 2 + 12 * ($numEntries - 1);
        my $fmt = Get16u($dataPt, $entry + 2);
        if ($fmt < 1 or $fmt > 13) {
            $et->HDump($entry+$dataPos+$base,12,"[invalid IFD entry]",
                       "Bad format type: $fmt", 1);
            # adjust the number of directory entries
            --$numEntries;
            $dirEnd -= 12;
        }
    }

    # make sure that Compression and SubfileType are defined for this IFD (for Condition's)
    $$et{Compression} = $$et{SubfileType} = '';

    # loop through all entries in an EXIF directory (IFD)
    my ($index, $valEnd, $offList, $offHash, $mapFmt);
    $mapFmt = $$tagTablePtr{VARS}{MAP_FORMAT} if $$tagTablePtr{VARS};

    my ($warnCount, $lastID) = (0, -1);
    for ($index=0; $index<$numEntries; ++$index) {
        if ($warnCount > 10) {
            $et->Warn("Too many warnings -- $dir parsing aborted", 2) and return 0;
        }
        my $entry = $dirStart + 2 + 12 * $index;
        my $tagID = Get16u($dataPt, $entry);
        my $format = Get16u($dataPt, $entry+2);
        my $count = Get32u($dataPt, $entry+4);
        if ($format < 1 or $format > 13) {
            if ($mapFmt and $$mapFmt{$format}) {
                $format = $$mapFmt{$format};
            } else {
                $et->HDump($entry+$dataPos+$base,12,"[invalid IFD entry]",
                           "Bad format type: $format", 1);
                # warn unless the IFD was just padded with zeros
                if ($format or $validate) {
                    $et->Warn("Bad format ($format) for $dir entry $index", $inMakerNotes);
                    ++$warnCount;
                }
                # assume corrupted IFD if this is our first entry (except Sony ILCE-7M2 firmware 1.21)
                return 0 unless $index or $$et{Model} eq 'ILCE-7M2';
                next;
            }
        }
        my $formatStr = $formatName[$format];   # get name of this format
        my $valueDataPt = $dataPt;
        my $valueDataPos = $dataPos;
        my $valueDataLen = $dataLen;
        my $valuePtr = $entry + 8;      # pointer to value within $$dataPt
        my $tagInfo = $et->GetTagInfo($tagTablePtr, $tagID);
        my ($origFormStr, $bad, $rational);
        # hack to patch incorrect count in Kodak SubIFD3 tags
        if ($count < 2 and ref $$tagTablePtr{$tagID} eq 'HASH' and $$tagTablePtr{$tagID}{FixCount}) {
            $offList or ($offList, $offHash) = GetOffList($dataPt, $dirStart, $dataPos,
                                                          $numEntries, $tagTablePtr);
            my $i = $$offHash{Get32u($dataPt, $valuePtr)};
            if (defined $i and $i < $#$offList) {
                my $oldCount = $count;
                $count = int(($$offList[$i+1] - $$offList[$i]) / $formatSize[$format]);
                $origFormStr = $formatName[$format] . '[' . $oldCount . ']' if $oldCount != $count;
            }
        }
        $validate and not $inMakerNotes and Image::ExifTool::Validate::ValidateExif(
            $et, $tagTablePtr, $tagID, $tagInfo, $lastID, $dir, $count, $formatStr);
        my $size = $count * $formatSize[$format];
        my $readSize = $size;
        if ($size > 4) {
            if ($size > 0x7fffffff) {
                $et->Warn(sprintf("Invalid size (%u) for %s tag 0x%.4x", $size, $dir, $tagID), $inMakerNotes);
                ++$warnCount;
                next;
            }
            $valuePtr = Get32u($dataPt, $valuePtr);
            if ($validate and not $inMakerNotes) {
                $et->Warn(sprintf('Odd offset for %s tag 0x%.4x', $dir, $tagID), 1) if $valuePtr & 0x01;
                if ($valuePtr < 8 || ($valuePtr + $size > length($$dataPt) and
                                      $valuePtr + $size > $$et{VALUE}{FileSize}))
                {
                    $et->Warn(sprintf("Invalid offset for %s tag 0x%.4x", $dir, $tagID));
                    ++$warnCount;
                    next;
                }
                if ($valuePtr + $size > $dirStart + $dataPos and $valuePtr < $dirEnd + $dataPos + 4) {
                    $et->Warn(sprintf("Value for %s tag 0x%.4x overlaps IFD", $dir, $tagID));
                }
            }
            # fix valuePtr if necessary
            if ($$dirInfo{FixOffsets}) {
                my $wFlag;
                $valEnd or $valEnd = $dataPos + $dirEnd + 4;
                #### eval FixOffsets ($valuePtr, $valEnd, $size, $tagID, $wFlag)
                eval $$dirInfo{FixOffsets};
            }
            my $suspect;
            # offset shouldn't point into TIFF header
            $valuePtr < 8 and not $$dirInfo{ZeroOffsetOK} and $suspect = $warnCount;
            # convert offset to pointer in $$dataPt
            if ($$dirInfo{EntryBased} or (ref $$tagTablePtr{$tagID} eq 'HASH' and
                $$tagTablePtr{$tagID}{EntryBased}))
            {
                $valuePtr += $entry;
            } else {
                $valuePtr -= $dataPos;
            }
            # value shouldn't overlap our directory
            $suspect = $warnCount if $valuePtr < $dirEnd and $valuePtr+$size > $dirStart;
            # load value from file if necessary
            if ($valuePtr < 0 or $valuePtr+$size > $dataLen) {
                # get value by seeking in file if we are allowed
                my $buff;
                if ($raf) {
                    # avoid loading large binary data unless necessary
                    # (eg. ImageSourceData -- layers in Photoshop TIFF image)
                    while ($size > BINARY_DATA_LIMIT) {
                        if ($tagInfo) {
                            # make large unknown blocks binary data
                            $$tagInfo{Binary} = 1 if $$tagInfo{Unknown};
                            last unless $$tagInfo{Binary};      # must read non-binary data
                            last if $$tagInfo{SubDirectory};    # must read SubDirectory data
                            my $lcTag = lc($$tagInfo{Name});
                            if ($$et{OPTIONS}{Binary} and
                                not $$et{EXCL_TAG_LOOKUP}{$lcTag})
                            {
                                # read binary data if specified unless tagsFromFile won't use it
                                last unless $$et{TAGS_FROM_FILE} and $$tagInfo{Protected};
                            }
                            # must read if tag is specified by name
                            last if $$et{REQ_TAG_LOOKUP}{$lcTag};
                        } else {
                            # must read value if needed for a condition
                            last if defined $tagInfo;
                        }
                        # (note: changing the value without changing $size will cause
                        # a warning in the verbose output, but we need to maintain the
                        # proper size for the htmlDump, so we can't change this)
                        $buff = "Binary data $size bytes";
                        $readSize = length $buff;
                        last;
                    }
                    # read from file if necessary
                    unless (defined $buff or
                            ($raf->Seek($base + $valuePtr + $dataPos,0) and
                             $raf->Read($buff,$size) == $size))
                    {
                        $et->Warn("Error reading value for $dir entry $index", $inMakerNotes);
                        return 0 unless $inMakerNotes or $htmlDump;
                        ++$warnCount;
                        $buff = '' unless defined $buff;
                        $readSize = length $buff;
                        $bad = 1;
                    }
                    $valueDataLen = length $buff;
                    $valueDataPt = \$buff;
                    $valueDataPos = $valuePtr + $dataPos;
                    $valuePtr = 0;
                } else {
                    my ($tagStr, $tmpInfo, $leicaTrailer);
                    if ($tagInfo) {
                        $tagStr = $$tagInfo{Name};
                        $leicaTrailer = $$tagInfo{LeicaTrailer};
                    } elsif (defined $tagInfo) {
                        $tmpInfo = $et->GetTagInfo($tagTablePtr, $tagID, \ '', $formatStr, $count);
                        if ($tmpInfo) {
                            $tagStr = $$tmpInfo{Name};
                            $leicaTrailer = $$tmpInfo{LeicaTrailer};
                        }
                    }
                    if ($tagInfo and $$tagInfo{ChangeBase}) {
                        # adjust base offset for this tag only
                        #### eval ChangeBase ($dirStart,$dataPos)
                        my $newBase = eval $$tagInfo{ChangeBase};
                        $valuePtr += $newBase;
                    }
                    $tagStr or $tagStr = sprintf("tag 0x%.4x",$tagID);
                    # allow PreviewImage to run outside EXIF data
                    if ($tagStr eq 'PreviewImage' and $$et{RAF}) {
                        my $pos = $$et{RAF}->Tell();
                        $buff = $et->ExtractBinary($base + $valuePtr + $dataPos, $size, 'PreviewImage');
                        $$et{RAF}->Seek($pos, 0);
                        $valueDataPt = \$buff;
                        $valueDataPos = $valuePtr + $dataPos;
                        $valueDataLen = $size;
                        $valuePtr = 0;
                    } elsif ($leicaTrailer and $$et{RAF}) {
                        if ($verbose > 0) {
                            $et->VPrint(0, "$$et{INDENT}$index) $tagStr --> (outside APP1 segment)\n");
                        }
                        if ($et->Options('FastScan')) {
                            $et->Warn('Ignored Leica MakerNote trailer');
                        } else {
                            require Image::ExifTool::Fixup;
                            $$et{LeicaTrailer} = {
                                TagInfo => $tagInfo || $tmpInfo,
                                Offset  => $base + $valuePtr + $dataPos,
                                Size    => $size,
                                Fixup   => new Image::ExifTool::Fixup,
                            };
                        }
                    } else {
                        $et->Warn("Bad offset for $dir $tagStr", $inMakerNotes);
                        ++$warnCount;
                    }
                    unless (defined $buff) {
                        $valueDataPt = '';
                        $valueDataPos = $valuePtr + $dataPos;
                        $valueDataLen = 0;
                        $valuePtr = 0;
                        $bad = 1;
                    }
                }
            }
            # warn about suspect offsets if they didn't already cause another warning
            if (defined $suspect and $suspect == $warnCount) {
                my $tagStr = $tagInfo ? $$tagInfo{Name} : sprintf('tag 0x%.4x', $tagID);
                if ($et->Warn("Suspicious $dir offset for $tagStr", $inMakerNotes)) {
                    ++$warnCount;
                    next unless $verbose;
                }
            }
        }
        # treat single unknown byte as int8u
        $formatStr = 'int8u' if $format == 7 and $count == 1;

        my ($val, $subdir, $wrongFormat);
        if ($tagID > 0xf000 and $tagTablePtr eq \%Image::ExifTool::Exif::Main) {
            my $oldInfo = $$tagTablePtr{$tagID};
            if ((not $oldInfo or (ref $oldInfo eq 'HASH' and $$oldInfo{Condition} and
                not $$oldInfo{PSRaw})) and not $bad)
            {
                # handle special case of Photoshop RAW tags (0xfde8-0xfe58)
                # --> generate tags from the value if possible
                $val = ReadValue($valueDataPt,$valuePtr,$formatStr,$count,$readSize);
                if (defined $val and $val =~ /(.*): (.*)/) {
                    my $tag = $1;
                    $val = $2;
                    $tag =~ s/'s//; # remove 's (so "Owner's Name" becomes "OwnerName")
                    $tag =~ tr/a-zA-Z0-9_//cd; # remove unknown characters
                    if ($tag) {
                        $tagInfo = {
                            Name => $tag,
                            Condition => '$$self{TIFF_TYPE} ne "DCR"',
                            ValueConv => '$_=$val;s/^.*: //;$_', # remove descr
                            PSRaw => 1, # (just as flag to avoid adding this again)
                        };
                        AddTagToTable($tagTablePtr, $tagID, $tagInfo);
                        # generate conditional list if a conditional tag already existed
                        $$tagTablePtr{$tagID} = [ $oldInfo, $tagInfo ] if $oldInfo;
                    }
                }
            }
        }
        if (defined $tagInfo and not $tagInfo) {
            if ($bad) {
                undef $tagInfo;
            } else {
                # GetTagInfo() required the value for a Condition
                my $tmpVal = substr($$valueDataPt, $valuePtr, $readSize < 128 ? $readSize : 128);
                # (use original format name in this call -- $formatStr may have been changed to int8u)
                $tagInfo = $et->GetTagInfo($tagTablePtr, $tagID, \$tmpVal,
                                           $formatName[$format], $count);
            }
        }
        # make sure we are handling the 'ifd' format properly
        if (($format == 13 or $format == 18) and (not $tagInfo or not $$tagInfo{SubIFD})) {
            my $str = sprintf('%s tag 0x%.4x IFD format not handled', $dirName, $tagID);
            $et->Warn($str, $inMakerNotes);
        }
        if (defined $tagInfo) {
            my $readFormat = $$tagInfo{Format};
            $subdir = $$tagInfo{SubDirectory};
            # unless otherwise specified, all SubDirectory data except
            # EXIF SubIFD offsets should be unformatted
            $readFormat = 'undef' if $subdir and not $$tagInfo{SubIFD} and not $readFormat;
            # override EXIF format if specified
            if ($readFormat) {
                $formatStr = $readFormat;
                my $newNum = $formatNumber{$formatStr};
                if ($newNum and $newNum != $format) {
                    $origFormStr = $formatName[$format] . '[' . $count . ']';
                    $format = $newNum;
                    $size = $readSize = $$tagInfo{FixedSize} if $$tagInfo{FixedSize};
                    # adjust number of items for new format size
                    $count = int($size / $formatSize[$format]);
                }
            }
            # verify that offset-type values are integral
            if (($$tagInfo{IsOffset} or $$tagInfo{SubIFD}) and not $intFormat{$formatStr}) {
                $et->Warn(sprintf('Wrong format (%s) for %s 0x%.4x %s',$formatStr,$dir,$tagID,$$tagInfo{Name}));
                if ($validate) {
                    $$et{WrongFormat}{"$dir:$$tagInfo{Name}"} = 1;
                    $offsetInfo{$tagID} = [ $tagInfo, '' ];
                }
                next unless $verbose;
                $wrongFormat = 1;
            }
        } else {
            next unless $verbose;
        }
        unless ($bad) {
            # limit maximum length of data to reformat
            # (avoids long delays when processing some corrupted files)
            if ($count > 100000 and $formatStr !~ /^(undef|string|binary)$/) {
                my $tagName = $tagInfo ? $$tagInfo{Name} : sprintf('tag 0x%.4x', $tagID);
                if ($tagName ne 'TransferFunction' or $count ne 196608) {
                    my $minor = $count > 2000000 ? 0 : 2;
                    next if $et->Warn("Ignoring $dirName $tagName with excessive count", $minor);
                }
            }
            # convert according to specified format
            $val = ReadValue($valueDataPt,$valuePtr,$formatStr,$count,$readSize,\$rational);
            # re-code if necessary
            if ($strEnc and $formatStr eq 'string' and defined $val) {
                $val = $et->Decode($val, $strEnc);
            }
        }

        if ($verbose) {
            my $tval = $val;
            # also show as a rational
            $tval .= " ($rational)" if defined $rational;
            if ($htmlDump) {
                my ($tagName, $colName);
                if ($tagID == 0x927c and $dirName eq 'ExifIFD') {
                    $tagName = 'MakerNotes';
                } elsif ($tagInfo) {
                    $tagName = $$tagInfo{Name};
                } else {
                    $tagName = sprintf("Tag 0x%.4x",$tagID);
                }
                my $dname = sprintf("${dir}-%.2d", $index);
                # build our tool tip
                $size < 0 and $size = $count * $formatSize[$format];
                my $fstr = "$formatName[$format]\[$count]";
                $fstr = "$origFormStr read as $fstr" if $origFormStr and $origFormStr ne $fstr;
                $fstr .= ' <-- WRONG' if $wrongFormat;
                my $tip = sprintf("Tag ID: 0x%.4x\n", $tagID) .
                          "Format: $fstr\nSize: $size bytes\n";
                if ($size > 4) {
                    my $offPt = Get32u($dataPt,$entry+8);
                    my $actPt = $valuePtr + $valueDataPos + $base - ($$et{EXIF_POS} || 0);
                    $tip .= sprintf("Value offset: 0x%.4x\n", $offPt);
                    # highlight tag name (red for bad size)
                    my $style = ($bad or not defined $tval) ? 'V' : 'H';
                    if ($actPt != $offPt) {
                        $tip .= sprintf("Actual offset: 0x%.4x\n", $actPt);
                        my $sign = $actPt < $offPt ? '-' : '';
                        $tip .= sprintf("Offset base: ${sign}0x%.4x\n", abs($actPt - $offPt));
                        $style = 'F' if $style eq 'H';  # purple for different offsets
                    }
                    $colName = "<span class=$style>$tagName</span>";
                    $colName .= ' <span class=V>(odd)</span>' if $offPt & 0x01;
                } else {
                    $colName = $tagName;
                }
                $colName .= ' <span class=V>(err)</span>' if $wrongFormat;
                $colName .= ' <span class=V>(seq)</span>' if $tagID <= $lastID and not $inMakerNotes;
                $lastID = $tagID;
                if (not defined $tval) {
                    $tval = '<bad size/offset>';
                } else {
                    $tval = substr($tval,0,28) . '[...]' if length($tval) > 32;
                    if ($formatStr =~ /^(string|undef|binary)/) {
                        # translate non-printable characters
                        $tval =~ tr/\x00-\x1f\x7f-\xff/./;
                    } elsif ($tagInfo and Image::ExifTool::IsInt($tval)) {
                        if ($$tagInfo{IsOffset} or $$tagInfo{SubIFD}) {
                            $tval = sprintf('0x%.4x', $tval);
                            my $actPt = $val + $base - ($$et{EXIF_POS} || 0);
                            if ($actPt != $val) {
                                $tval .= sprintf("\nActual offset: 0x%.4x", $actPt);
                                my $sign = $actPt < $val ? '-' : '';
                                $tval .= sprintf("\nOffset base: ${sign}0x%.4x", abs($actPt - $val));
                            }
                        } elsif ($$tagInfo{PrintHex}) {
                            $tval = sprintf('0x%x', $tval);
                        }
                    }
                }
                $tip .= "Value: $tval";
                $et->HDump($entry+$dataPos+$base, 12, "$dname $colName", $tip, 1);
                next if $valueDataLen < 0;  # don't process bad pointer entry
                if ($size > 4) {
                    my $exifDumpPos = $valuePtr + $valueDataPos + $base;
                    my $flag = 0;
                    if ($subdir) {
                        if ($$tagInfo{MakerNotes}) {
                            $flag = 0x04;
                        } elsif ($$tagInfo{NestedHtmlDump}) {
                            $flag = $$tagInfo{NestedHtmlDump} == 2 ? 0x10 : 0x04;
                        }
                    }
                    # add value data block (underlining maker notes data)
                    $et->HDump($exifDumpPos,$size,"$tagName value",'SAME', $flag);
                }
            } else {
                if ($tagID <= $lastID and not $inMakerNotes) {
                    $et->Warn(sprintf('Tag ID 0x%.4x out of sequence in %s', $tagID, $dirName));
                }
                $lastID = $tagID;
                if ($verbose > 0) {
                    my $fstr = $formatName[$format];
                    $fstr = "$origFormStr read as $fstr" if $origFormStr;
                    $et->VerboseInfo($tagID, $tagInfo,
                        Table   => $tagTablePtr,
                        Index   => $index,
                        Value   => $tval,
                        DataPt  => $valueDataPt,
                        DataPos => $valueDataPos + $base,
                        Size    => $size,
                        Start   => $valuePtr,
                        Format  => $fstr,
                        Count   => $count,
                    );
                }
            }
            next if not $tagInfo or $wrongFormat;
        }
        next unless defined $val;
#..............................................................................
# Handle SubDirectory tag types
#
        if ($subdir) {
            # don't process empty subdirectories
            unless ($size) {
                unless ($$tagInfo{MakerNotes} or $inMakerNotes) {
                    $et->Warn("Empty $$tagInfo{Name} data", 1);
                }
                next;
            }
            my (@values, $newTagTable, $dirNum, $newByteOrder, $invalid);
            my $tagStr = $$tagInfo{Name};
            if ($$subdir{MaxSubdirs}) {
                @values = split ' ', $val;
                # limit the number of subdirectories we parse
                my $over = @values - $$subdir{MaxSubdirs};
                if ($over > 0) {
                    $et->Warn("Ignoring $over $tagStr directories");
                    splice @values, $$subdir{MaxSubdirs};
                }
                $val = shift @values;
            }
            if ($$subdir{TagTable}) {
                $newTagTable = GetTagTable($$subdir{TagTable});
                $newTagTable or warn("Unknown tag table $$subdir{TagTable}"), next;
            } else {
                $newTagTable = $tagTablePtr;    # use existing table
            }
            # loop through all sub-directories specified by this tag
            for ($dirNum=0; ; ++$dirNum) {
                my $subdirBase = $base;
                my $subdirDataPt = $valueDataPt;
                my $subdirDataPos = $valueDataPos;
                my $subdirDataLen = $valueDataLen;
                my $subdirStart = $valuePtr;
                if (defined $$subdir{Start}) {
                    # set local $valuePtr relative to file $base for eval
                    my $valuePtr = $subdirStart + $subdirDataPos;
                    #### eval Start ($valuePtr, $val)
                    my $newStart = eval($$subdir{Start});
                    unless (Image::ExifTool::IsInt($newStart)) {
                        $et->Warn("Bad value for $tagStr");
                        last;
                    }
                    # convert back to relative to $subdirDataPt
                    $newStart -= $subdirDataPos;
                    # adjust directory size if necessary
                    unless ($$tagInfo{SubIFD} or $$subdir{BadOffset}) {
                        $size -= $newStart - $subdirStart;
                    }
                    $subdirStart = $newStart;
                }
                # this is a pain, but some maker notes are always a specific
                # byte order, regardless of the byte order of the file
                my $oldByteOrder = GetByteOrder();
                $newByteOrder = $$subdir{ByteOrder};
                if ($newByteOrder) {
                    if ($newByteOrder =~ /^Little/i) {
                        $newByteOrder = 'II';
                    } elsif ($newByteOrder =~ /^Big/i) {
                        $newByteOrder = 'MM';
                    } elsif ($$subdir{OffsetPt}) {
                        undef $newByteOrder;
                        warn "Can't have variable byte ordering for SubDirectories using OffsetPt";
                        last;
                    } elsif ($subdirStart + 2 <= $subdirDataLen) {
                        # attempt to determine the byte ordering by checking
                        # the number of directory entries.  This is an int16u
                        # that should be a reasonable value.
                        my $num = Get16u($subdirDataPt, $subdirStart);
                        if ($num & 0xff00 and ($num>>8) > ($num&0xff)) {
                            # This looks wrong, we shouldn't have this many entries
                            my %otherOrder = ( II=>'MM', MM=>'II' );
                            $newByteOrder = $otherOrder{$oldByteOrder};
                        } else {
                            $newByteOrder = $oldByteOrder;
                        }
                    }
                } else {
                    $newByteOrder = $oldByteOrder;
                }
                # set base offset if necessary
                if ($$subdir{Base}) {
                    # calculate subdirectory start relative to $base for eval
                    my $start = $subdirStart + $subdirDataPos;
                    #### eval Base ($start,$base)
                    $subdirBase = eval($$subdir{Base}) + $base;
                }
                # add offset to the start of the directory if necessary
                if ($$subdir{OffsetPt}) {
                    #### eval OffsetPt ($valuePtr)
                    my $pos = eval $$subdir{OffsetPt};
                    if ($pos + 4 > $subdirDataLen) {
                        $et->Warn("Bad $tagStr OffsetPt");
                        last;
                    }
                    SetByteOrder($newByteOrder);
                    $subdirStart += Get32u($subdirDataPt, $pos);
                    SetByteOrder($oldByteOrder);
                }
                if ($subdirStart < 0 or $subdirStart + 2 > $subdirDataLen) {
                    # convert $subdirStart back to a file offset
                    if ($raf) {
                        # reset SubDirectory buffer (we will load it later)
                        my $buff = '';
                        $subdirDataPt = \$buff;
                        $subdirDataLen = $size = length $buff;
                    } else {
                        my $msg = "Bad $tagStr SubDirectory start";
                        if ($verbose > 0) {
                            if ($subdirStart < 0) {
                                $msg .= " (directory start $subdirStart is before EXIF start)";
                            } else {
                                my $end = $subdirStart + $size;
                                $msg .= " (directory end is $end but EXIF size is only $subdirDataLen)";
                            }
                        }
                        $et->Warn($msg);
                        last;
                    }
                }

                # must update subdirDataPos if $base changes for this subdirectory
                $subdirDataPos += $base - $subdirBase;

                # build information hash for new directory
                my %subdirInfo = (
                    Name       => $tagStr,
                    Base       => $subdirBase,
                    DataPt     => $subdirDataPt,
                    DataPos    => $subdirDataPos,
                    DataLen    => $subdirDataLen,
                    DirStart   => $subdirStart,
                    DirLen     => $size,
                    RAF        => $raf,
                    Parent     => $dirName,
                    DirName    => $$subdir{DirName},
                    FixBase    => $$subdir{FixBase},
                    FixOffsets => $$subdir{FixOffsets},
                    EntryBased => $$subdir{EntryBased},
                    TagInfo    => $tagInfo,
                    SubIFD     => $$tagInfo{SubIFD},
                    Subdir     => $subdir,
                );
                # (remember: some cameras incorrectly write maker notes in IFD0)
                if ($$tagInfo{MakerNotes}) {
                    # don't parse makernotes if FastScan > 1
                    my $fast = $et->Options('FastScan');
                    last if $fast and $fast > 1;
                    $subdirInfo{MakerNoteAddr} = $valuePtr + $valueDataPos + $base;
                    $subdirInfo{NoFixBase} = 1 if defined $$subdir{Base};
                }
                # set directory IFD name from group name of family 1 if it exists,
                # unless the tag is writable as a block in which case group 1 may
                # have been set automatically
                if ($$tagInfo{Groups} and not $$tagInfo{Writable}) {
                    $subdirInfo{DirName} = $$tagInfo{Groups}{1};
                    # number multiple subdirectories
                    $subdirInfo{DirName} =~ s/\d*$/$dirNum/ if $dirNum;
                }
                SetByteOrder($newByteOrder);    # set byte order for this subdir
                # validate the subdirectory if necessary
                my $dirData = $subdirDataPt;    # set data pointer to be used in eval
                #### eval Validate ($val, $dirData, $subdirStart, $size)
                my $ok = 0;
                if (defined $$subdir{Validate} and not eval $$subdir{Validate}) {
                    $et->Warn("Invalid $tagStr data");
                    $invalid = 1;
                } else {
                    if (not $subdirInfo{DirName} and $inMakerNotes) {
                        $subdirInfo{DirName} = $$tagInfo{Name};
                    }
                    # process the subdirectory
                    $ok = $et->ProcessDirectory(\%subdirInfo, $newTagTable, $$subdir{ProcessProc});
                }
                # print debugging information if there were errors
                if (not $ok and $verbose > 1 and $subdirStart != $valuePtr) {
                    my $out = $et->Options('TextOut');
                    printf $out "%s    (SubDirectory start = 0x%x)\n", $$et{INDENT}, $subdirStart;
                }
                SetByteOrder($oldByteOrder);    # restore original byte swapping

                @values or last;
                $val = shift @values;           # continue with next subdir
            }
            my $doMaker = $et->Options('MakerNotes');
            next unless $doMaker or $$et{REQ_TAG_LOOKUP}{lc($tagStr)} or $$tagInfo{BlockExtract};
            # extract as a block if specified
            if ($$tagInfo{MakerNotes}) {
                # save maker note byte order (if it was significant and valid)
                if ($$subdir{ByteOrder} and not $invalid) {
                    $$et{MAKER_NOTE_BYTE_ORDER} =
                        defined ($$et{UnknownByteOrder}) ?
                                 $$et{UnknownByteOrder} : $newByteOrder;
                }
                if ($doMaker and $doMaker eq '2') {
                    # extract maker notes without rebuilding (no fixup information)
                    delete $$et{MAKER_NOTE_FIXUP};
                } elsif (not $$tagInfo{NotIFD}) {
                    # this is a pain, but we must rebuild EXIF-typemaker notes to
                    # include all the value data if data was outside the maker notes
                    my %makerDirInfo = (
                        Name       => $tagStr,
                        Base       => $base,
                        DataPt     => $valueDataPt,
                        DataPos    => $valueDataPos,
                        DataLen    => $valueDataLen,
                        DirStart   => $valuePtr,
                        DirLen     => $size,
                        RAF        => $raf,
                        Parent     => $dirName,
                        DirName    => 'MakerNotes',
                        FixOffsets => $$subdir{FixOffsets},
                        TagInfo    => $tagInfo,
                    );
                    $makerDirInfo{FixBase} = 1 if $$subdir{FixBase};
                    # rebuild maker notes (creates $$et{MAKER_NOTE_FIXUP})
                    my $val2 = RebuildMakerNotes($et, $newTagTable, \%makerDirInfo);
                    if (defined $val2) {
                        $val = $val2;
                    } elsif ($size > 4) {
                        $et->Warn('Error rebuilding maker notes (may be corrupt)');
                    }
                }
            } else {
                # extract this directory as a block if specified
                next unless $$tagInfo{Writable};
            }
        }
 #..............................................................................
        # convert to absolute offsets if this tag is an offset
        #### eval IsOffset ($val, $et)
        if ($$tagInfo{IsOffset} and eval $$tagInfo{IsOffset}) {
            my $offsetBase = $$tagInfo{IsOffset} eq '2' ? $firstBase : $base;
            $offsetBase += $$et{BASE};
            # handle offsets which use a wrong base (Minolta A200)
            if ($$tagInfo{WrongBase}) {
                my $self = $et;
                #### eval WrongBase ($self)
                $offsetBase += eval $$tagInfo{WrongBase} || 0;
            }
            my @vals = split(' ',$val);
            foreach $val (@vals) {
                $val += $offsetBase;
            }
            $val = join(' ', @vals);
        }
        if ($validate and $$tagInfo{OffsetPair}) {
            $offsetInfo{$tagID} = [ $tagInfo, $val ];
        }
        # save the value of this tag
        $tagKey = $et->FoundTag($tagInfo, $val);
        if (defined $tagKey) {
            # set the group 1 name for tags in specified tables
            $et->SetGroup($tagKey, $dirName) if $$tagTablePtr{SET_GROUP1};
            # save original components of rational numbers (used when copying)
            $$et{RATIONAL}{$tagKey} = $rational if defined $rational;
        }
    }

    # validate image data offsets
    if ($validate and %offsetInfo) {
        Image::ExifTool::Validate::ValidateOffsetInfo($et, \%offsetInfo, $$dirInfo{DirName}, $inMakerNotes)
    }

    # scan for subsequent IFD's if specified
    if ($$dirInfo{Multi} and $bytesFromEnd >= 4) {
        my $offset = Get32u($dataPt, $dirEnd);
        if ($offset) {
            my $subdirStart = $offset - $dataPos;
            # use same directory information for trailing directory,
            # but change the start location (ProcessDirectory will
            # test to make sure we don't reprocess the same dir twice)
            my %newDirInfo = %$dirInfo;
            $newDirInfo{DirStart} = $subdirStart;
            # increment IFD number
            my $ifdNum = $newDirInfo{DirName} =~ s/(\d+)$// ? $1 : 0;
            $newDirInfo{DirName} .= $ifdNum + 1;
            # must validate SubIFD1 because the nextIFD pointer is invalid for some RAW formats
            if ($newDirInfo{DirName} ne 'SubIFD1' or ValidateIFD(\%newDirInfo)) {
                $$et{INDENT} =~ s/..$//; # keep indent the same
                my $cur = pop @{$$et{PATH}};
                $et->ProcessDirectory(\%newDirInfo, $tagTablePtr) or $success = 0;
                push @{$$et{PATH}}, $cur;
            } elsif ($verbose or $$et{TIFF_TYPE} eq 'TIFF') {
                $et->Warn('Ignored bad IFD linked from SubIFD');
            }
        }
    }
    return $success;
}

1; # end

__END__

=head1 NAME

Image::ExifTool::Exif - Read EXIF/TIFF meta information

=head1 SYNOPSIS

This module is required by Image::ExifTool.

=head1 DESCRIPTION

This module contains routines required by Image::ExifTool for processing
EXIF and TIFF meta information.

=head1 AUTHOR

Copyright 2003-2018, Phil Harvey (phil at owl.phy.queensu.ca)

This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

=head1 REFERENCES

=over 4

=item L<http://www.exif.org/Exif2-2.PDF>

=item L<http://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf>

=item L<http://partners.adobe.com/asn/developer/pdfs/tn/TIFF6.pdf>

=item L<http://partners.adobe.com/public/developer/en/tiff/TIFFPM6.pdf>

=item L<http://www.adobe.com/products/dng/pdfs/dng_spec.pdf>

=item L<http://www.awaresystems.be/imaging/tiff/tifftags.html>

=item L<http://www.remotesensing.org/libtiff/TIFFTechNote2.html>

=item L<http://www.exif.org/dcf.PDF>

=item L<http://park2.wakwak.com/~tsuruzoh/Computer/Digicams/exif-e.html>

=item L<http://www.fine-view.com/jp/lab/doc/ps6ffspecsv2.pdf>

=item L<http://www.ozhiker.com/electronics/pjmt/jpeg_info/meta.html>

=item L<http://hul.harvard.edu/jhove/tiff-tags.html>

=item L<http://www.microsoft.com/whdc/xps/wmphoto.mspx>

=item L<http://www.asmail.be/msg0054681802.html>

=item L<http://crousseau.free.fr/imgfmt_raw.htm>

=item L<http://www.cybercom.net/~dcoffin/dcraw/>

=item L<http://www.digitalpreservation.gov/formats/content/tiff_tags.shtml>

=item L<http://community.roxen.com/developers/idocs/rfc/rfc3949.html>

=item L<http://tools.ietf.org/html/draft-ietf-fax-tiff-fx-extension1-01>

=item L<http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/cinemadng/pdfs/CinemaDNG_Format_Specification_v1_1.pdf>

=item L<http://geotiff.maptools.org/spec/geotiffhome.html>

=back

=head1 ACKNOWLEDGEMENTS

Thanks to Jeremy Brown for the 35efl tags, and Matt Madrid for his help with
the XP character code conversions.

=head1 SEE ALSO

L<Image::ExifTool::TagNames/EXIF Tags>,
L<Image::ExifTool(3pm)|Image::ExifTool>

=cut
