


IMMONO(1IM)                IMAGE TOOLS                IMMONO(1IM)



NAME
     immono  -  Convert an image to monochrome

SYNOPSIS
     immono [_o_p_t_i_o_n_s] _i_n_f_i_l_e_n_a_m_e _o_u_t_f_i_l_e_n_a_m_e

DESCRIPTION
     immono converts an input image to monochrome, then writes it
     to  an output image file.  If the input file contains multi-
     ple images, immono converts each one and writes  it  to  the
     output file.  The input and output image file formats may be
     different.

OPTIONS
     immono has a  variety  of  options  in  the  following  five
     categories:

          File Selection     What input and output files to use
          Format Selection   What image file format to use
          Format Control     What variant of a file format to generate
          Standard           Standard generic options on all SDSC tools
          Manipulation       How the image can be manipulated

     _F_i_l_e _S_e_l_e_c_t_i_o_n, _F_o_r_m_a_t _S_e_l_e_c_t_i_o_n, _F_o_r_m_a_t _C_o_n_t_r_o_l, and  _S_t_a_n_-
     _d_a_r_d options are common to all SDSC image tools and are dis-
     cussed in depth in the man page for imconv(1IM).

     All options can be abbreviated to the first few unique char-
     acters.

  Manipulation Options
     Conversion of an input image to  monochrome  is  a  two-step
     process:

          1.   Convert the color image to grayscale.
          2.   Convert the grayscale image to monochrome.

     In step 1, conversion from color to grayscale  computes  the
     gray value for each pixel using the NTSC Y equation:

               Gray ~~=~~ 0.30*R ~+~ 0.59*G ~+~ 0.11*B

     In step 2, conversion from grayscale pixel values (0-255) to
     monochrome  pixel values (0 or 1) uses a simple thresholding
     technique.  Pixel values equal to or higher than the  thres-
     hold are considered white.  Pixel values below the threshold
     are considered black.

     By default, the threshold is set at 127.  This threshold may
     be  selected explicitly using -threshold followed by a posi-
     tive integer.




SDSC              Last change: August 26, 1992                  1






IMMONO(1IM)                IMAGE TOOLS                IMMONO(1IM)



NOTES
     For notes regarding  file  format  conversion  and  standard
     image tool options, see the man page on imconv(1IM).

     Error messages are reported to stderr.

EXAMPLES
     To convert an RGB Alias pix file  image  to  monochrome  and
     store  it in a Sun ras file, enter any of the following com-
     mand lines:

          immono picture.pix picture.ras
              or
          immono -pix picture.pix -ras picture.ras
              or
          immono -pix - picture.ras < picture.pix
              or
          immono -pix picture.pix -ras - > picture.ras
              or
          immono -pix - -ras - < picture.pix > picture.ras
              or
          cat picture.pix | immono -pix - -ras - | cat > picture.ras

SEE ALSO
     imconv (1IM), imfile (1IM), imformat  (1IM),  imgray  (1IM),
     ImVfbToMono (3IM)

     For information on SDSC's image library, see imintro(3IM).

     For information on the individual image  file  formats,  see
     their  respective man pages: imbmp (3IM), imcur (3IM), imeps
     (3IM), imgif (3IM), imhdf (3IM), imico (3IM), imicon  (3IM),
     imiff  (3IM),  immpnt (3IM), impbm (3IM), impcx (3IM), impgm
     (3IM), impic (3IM), impict (3IM), impix (3IM), impnm  (3IM),
     imppm  (3IM),  imps  (3IM),  imras (3IM), imrgb (3IM), imrla
     (3IM), imrle  (3IM),  imrpbm  (3IM),  imrpgm  (3IM),  imrpnm
     (3IM),  imrppm  (3IM),  imsynu  (3IM),  imtga  (3IM), imtiff
     (3IM), imviff (3IM), imx (3IM), imxbm (3IM), imxwd (3IM)

KNOWN PROBLEMS
     Dithering should be supported.

AUTHOR
     Dave Nadeau
     San Diego Supercomputer Center

     See the individual file format man pages for the authors  of
     the  underlying  format  read  and write code.  The names of
     these man pages begin with the letters "im" followed by  the
     format  name.  For example, the name of the TIFF man page is
     imtiff.  To display it, enter man imtiff.




2                 Last change: August 26, 1992               SDSC






IMMONO(1IM)                IMAGE TOOLS                IMMONO(1IM)



CONTACT
     SDSC consultants, (619)534-5100, consult@y1.sdsc.edu





















































SDSC              Last change: August 26, 1992                  3



