Class ArrayConverter

Method Details

• checkArray

  private static void checkArray(byte[] array, int offset, int length) throws IllegalArgumentException

  Makes sure that the arguments define a valid (existing) array interval. This includes:

  • array is non-null
  • offset is >= 0 and smaller than array.length
  • length is > 0
  • offset + length is <= array.length

  Throws:

  IllegalArgumentException

• convertPacked2BitIntensityTo8Bit

  public static void convertPacked2BitIntensityTo8Bit(byte[] src, int srcOffset, byte[] dest, int destOffset, int numPackedBytes)

  Converts bytes with two four-bit-intensity samples to 8 byte intensity values, each stored in one byte. Two-bit values can be 0, 1, 2 or 3. These values will be scaled to the full [0;255] range so that 0 remains 0, 1 becomes 85, 2 becomes 170 and 3 becomes 255.

  A little discussion on how to implement this method was held in the German Java newsgroup de.comp.lang.java. The message I wrote to start the thread has the ID 1ef7du4vfqsd2pskb6jukut6pnhn87htt2@4ax.com. Read the thread at Google Groups.

  Parameters:

  src - byte array, each byte stores four two-bit intensity values

  srcOffset - index into src

  dest - byte array, each byte stores an eight-bit intensity values

  destOffset - index into dest

  numPackedBytes - number of bytes in src to be decoded

• convertPacked4BitIntensityTo8Bit

  public static void convertPacked4BitIntensityTo8Bit(byte[] src, int srcOffset, byte[] dest, int destOffset, int numPackedBytes)

  Converts bytes with four two-bit-intensity samples to byte-sized intensity values. Four-bit values can be from 0 to 15. These values will be scaled to the full [0;255] range so that 0 remains 0, 1 becomes 17, 2 becomes 34, ..., and 15 becomes 255. The most significant four bits in a byte become the left, the least significant four bits the right pixel.

  Parameters:

  src - byte array, each byte stores two four-bit intensity values

  srcOffset - index into src

  dest - byte array, each byte stores an eight-bit intensity values

  destOffset - index into dest

  numPackedBytes - number of bytes in src to be decoded

  Since:

  0.12.0

• copyPackedBytes

  public static void copyPackedBytes(byte[] src, int srcOffset, int srcBitOffset, byte[] dest, int destOffset, int destBitOffset, int numSamples)

  Copies a number of bit values from one byte array to another.

  Parameters:

  src - array from which is copied

  srcOffset - index into the src array of the first byte from which is copied

  srcBitOffset - first bit within src[srcOffset] from which is copied (0 is left-most, 1 is second left-most, 7 is right-most)

  dest - array to which is copied

  destOffset - index into the dest array of the first byte to which is copied

  destBitOffset - first bit within dest[destOffset] to which is copied (0 is left-most, 1 is second left-most, 7 is right-most)

  numSamples - number of bits to be copied

• decodePacked1Bit

  public static void decodePacked1Bit(byte[] src, int srcOffset, byte[] dest, int destOffset, int numPackedBytes)

• decodePacked2Bit

  public static void decodePacked2Bit(byte[] src, int srcOffset, byte[] dest, int destOffset, int numPackedBytes)

  Decodes bytes with four two-bit samples to single bytes. The two most significant bits of a source byte become the first value, the two least significant bits the fourth value. The method expects numPackedBytes bytes at src[srcOffset] (these will be read and interpreted) and numPackedBytes * 4 at dest[destOffset] (where the decoded byte values will be stored.

  Parameters:

  src - byte array, each byte stores four two-bit values

  srcOffset - index into src

  dest - byte array, each byte stores a single decoded value (from 0 to 3)

  destOffset - index into dest

  numPackedBytes - number of bytes in src to be decoded

  Since:

  0.10.0

• decodePacked4Bit

  public static void decodePacked4Bit(byte[] src, int srcOffset, byte[] dest, int destOffset, int numPackedBytes)

  Decodes bytes with two four-bit samples to single bytes. The four most significant bits of a source byte become the first value, the least significant four bits the second value. The method expects numPackedBytes bytes at src[srcOffset] (these will be read and interpreted) and numPackedBytes * 2 at dest[destOffset] (where the decoded byte values will be stored.

  Parameters:

  src - byte array, each byte stores two four-bit values

  srcOffset - index into src

  dest - byte array, each byte stores a single decoded value

  destOffset - index into dest

  numPackedBytes - number of bytes in src to be decoded

• decodePackedRGB565BigEndianToRGB24

  public static void decodePackedRGB565BigEndianToRGB24(byte[] src, int srcOffset, byte[] red, int redOffset, byte[] green, int greenOffset, byte[] blue, int blueOffset, int numPixels)

  Convert 16 bit RGB samples stored in big endian (BE) byte order with 5 bits for red and blue and 6 bits for green to 24 bit RGB byte samples.

  Since:

  0.10.0

• encodePacked2Bit

  public static void encodePacked2Bit(byte[] src, int srcOffset, byte[] dest, int destOffset, int numSamples)

• encodePacked4Bit

  public static void encodePacked4Bit(byte[] src, int srcOffset, byte[] dest, int destOffset, int numSamples)

• encodeRGB24ToPackedRGB565BigEndian

  public static void encodeRGB24ToPackedRGB565BigEndian(byte[] red, int redOffset, byte[] green, int greenOffset, byte[] blue, int blueOffset, byte[] dest, int destOffset, int numPixels)

  Convert 24 bit RGB pixels to 16 bit pixels stored in big endian (BE) byte order with 5 bits for red and blue and 6 bits for green.

  Since:

  0.10.0

• getIntBE

  public static int getIntBE(byte[] src, int srcOffset)

  Reads four consecutive bytes from the given array at the given position in big endian order and returns them as an int.

  Parameters:

  src - the array from which bytes are read

  srcOffset - the index into the array from which the bytes are read

  Returns:

  int value taken from the array

• getIntLE

  public static int getIntLE(byte[] src, int srcOffset)

  Reads four consecutive bytes from the given array at the given position in little endian order and returns them as an int.

  Parameters:

  src - the array from which bytes are read

  srcOffset - the index into the array from which the bytes are read

  Returns:

  short value taken from the array

• getShortBE

  public static short getShortBE(byte[] src, int srcOffset)

  Reads two consecutive bytes from the given array at the given position in big endian order and returns them as a short.

  Parameters:

  src - the array from which two bytes are read

  srcOffset - the index into the array from which the two bytes are read

  Returns:

  short value taken from the array

• getShortBEAsInt

  public static int getShortBEAsInt(byte[] src, int srcOffset)

• getShortLE

  public static short getShortLE(byte[] src, int srcOffset)

  Reads two consecutive bytes from the given array at the given position in little endian order and returns them as a short.

  Parameters:

  src - the array from which two bytes are read

  srcOffset - the index into the array from which the two bytes are read

  Returns:

  short value taken from the array

• setIntBE

  public static void setIntBE(byte[] dest, int destOffset, int newValue)

  Writes an int value into four consecutive bytes of a byte array, in big endian (network) byte order.

  Parameters:

  dest - the array to which bytes are written

  destOffset - index of the array to which the first byte is written

  newValue - the int value to be written to the array

• setIntLE

  public static void setIntLE(byte[] dest, int destOffset, int newValue)

  Writes an int value into four consecutive bytes of a byte array, in little endian (Intel) byte order.

  Parameters:

  dest - the array to which bytes are written

  destOffset - index of the array to which the first byte is written

  newValue - the int value to be written to the array

• setShortBE

  public static void setShortBE(byte[] dest, int destOffset, short newValue)

• setShortLE

  public static void setShortLE(byte[] dest, int destOffset, short newValue)