tiffmedian(1) LibTIFF 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 colormap.
OPTIONS
-c Specify the compression to use for data written to the output
file: -c none for no compression, -c packbits for PackBits
compression, -c lzw for Lempel-Ziv & Welch compression, -c 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), tiff2cmp(1), libtiff(3),
"Color Image Quantization for Frame Buffer Display", Paul Heckbert,
SIGGRAPH proceedings, 1982, pp. 297-307.
AUTHOR
LibTIFF contributors
COPYRIGHT
1988-2022, LibTIFF contributors
4.5 December 23, 2022 tiffmedian(1)
tiff 4.5.0 - Generated Sat Dec 24 13:06:07 CST 2022