TIFFMEDIAN(1)TIFFMEDIAN(1)NAMEtiffmedian - apply the median cut algorithm to data in a
TIFF file
SYNOPSIStiffmedian [ options ] input.tif output.tif
DESCRIPTIONtiffmedian applys 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 colormap.
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 hori
zontal 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 gener
ated 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 pro
gram.
SEE ALSOpal2rgb(1), tiffinfo(1), tiffcp(1), tiffcmp(1), libtiff(3)
"Color Image Quantization for Frame Buffer Display", Paul
Heckbert, SIGGRAPH proceedings, 1982, pp. 297-307.
October 15, 1995 TIFFMEDIAN(1)
