tiffmedian - apply the median cut algorithm to data in a TIFF file
tiffmedian [ options ] input.tif output.tif
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-
-c Specify the compression to use for data written to the output
file: none for no compression, packbits for PackBits compres-
sion, 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
LZW compression can be specified together with a predictor
value. A predictor value of 2 causes each scanline of the out-
put 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
-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.
This program is derived from Paul Heckbert’s median program.
pal2rgb(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)
Man(1) output converted with