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tiffdither(1) [suse man page]

TIFFDITHER(1)						      General Commands Manual						     TIFFDITHER(1)

NAME

       tiffdither - convert a greyscale image to bilevel using dithering

SYNOPSIS

       tiffdither [ options ] input.tif output.tif

DESCRIPTION

       tiffdither converts a single channel 8-bit greyscale image to a bilevel image using Floyd-Steinberg error propagation with thresholding.

OPTIONS

       -c     Specify  the compression to use for data written to the output file: none for no compression, packbits for PackBits compression, lzw
	      for Lempel-Ziv & Welch compression, zip for Deflate compression, g3 for CCITT Group 3 (T.4) compression, and g4 for  CCITT  Group  4
	      (T.6) compression.  By default tiffdither will compress data according to the value of the Compression tag found in the source file.

	      The CCITT Group 3 and Group 4 compression algorithms can only be used with bilevel data.

	      Group 3 compression can be specified together with several T.4-specific options: 1d for 1-dimensional encoding, 2d for 2-dimensional
	      encoding, and fill to force each encoded scanline to be zero-filled so that the terminating EOL code lies on a byte boundary.  Group
	      3-specific  options  are	specified  by appending a ``:''-separated list to the ``g3'' option; e.g.  -c g3:2d:fill to get 2D-encoded
	      data with byte-aligned EOL codes.

	      LZW compression can be specified together with a predictor value.  A predictor value of 2 causes each scanline of the  output  image
	      to undergo horizontal differencing before it is encoded; a value of 1 forces each scanline to be encoded without differencing.  LZW-
	      specific options are specified by appending a ``:''-separated list to the ``lzw'' option; e.g.  -c lzw:2 for  LZW  compression  with
	      horizontal differencing.

       -f     Specify the bit fill order to use in writing output data.  By default, tiffdither will create a new file with the same fill order as
	      the original.  Specifying -f lsb2msb will force data to be written with the FillOrder tag set to LSB2MSB ,  while  -f  msb2lsb  will
	      force data to be written with the FillOrder tag set to MSB2LSB .

       -t     Set the threshold value for dithering.  By default the threshold value is 128.

NOTES

       The dither algorithm is taken from the tiffmedian(1) program (written by Paul Heckbert).

SEE ALSO

       pal2rgb(1), fax2tiff(1), tiffinfo(1), tiffcp(1), tiff2bw(1), libtiff(3TIFF)

       Libtiff library home page: http://www.remotesensing.org/libtiff/

libtiff 							September 20, 2005						     TIFFDITHER(1)

Check Out this Related Man Page

TIFFMEDIAN(1)						      General Commands Manual						     TIFFMEDIAN(1)

NAME

       tiffmedian - apply the median cut algorithm to data in a TIFF file

SYNOPSIS

       tiffmedian [ options ] input.tif output.tif

DESCRIPTION

       tiffmedian  applies  the  median cut algorithm to an RGB image in input.tif to generate a palette image that is written to output.tif.  The
       generated colormap has, by default, 256 entries.  The image data is quantized by mapping each pixel to the closest color values in the col-
       ormap.

OPTIONS

       -c     Specify  the compression to use for data written to the output file: none for no compression, packbits for PackBits compression, lzw
	      for Lempel-Ziv & Welch compression, and zip for Deflate compression.  By default tiffmedian will	compress  data	according  to  the
	      value of the Compression tag found in the source file.

	      LZW  compression	can be specified together with a predictor value.  A predictor value of 2 causes each scanline of the output image
	      to undergo horizontal differencing before it is encoded; a value of 1 forces each scanline to be encoded without differencing.  LZW-
	      specific	options  are  specified by appending a ``:''-separated list to the ``lzw'' option; e.g.  -c lzw:2 for LZW compression with
	      horizontal differencing.

       -C     Specify the number of entries to use in the generated colormap.  By default all 256 entries/colors are used.

       -f     Apply Floyd-Steinberg dithering before selecting a colormap entry.

       -r     Specify the number of rows (scanlines) in each strip of data written to the output file.	By default, tiffmedian attempts to set the
	      rows/strip that no more than 8 kilobytes of data appear in a strip.

NOTES

       This program is derived from Paul Heckbert's median program.

SEE ALSO

       pal2rgb(1), tiffinfo(1), tiffcp(1), tiffcmp(1), libtiff(3TIFF)

       Color Image Quantization for Frame Buffer Display, Paul Heckbert, SIGGRAPH proceedings, 1982, pp. 297-307.

       Libtiff library home page: http://www.remotesensing.org/libtiff/

libtiff 							 November 2, 2005						     TIFFMEDIAN(1)
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