NAME
mcut - Quantize colors in an image using the
median cut algorithm
SYNOPSIS
mcut [ -n colors ] [ -d ] [ -o outfile ] infile
DESCRIPTION
Mcut reads an RLE file and tries to choose
the "best" subset of colors to represent the
colors present in the original image. A
common use for this is to display a 24 bit
image on a frame buffer with only eight bits
per pixel using a 24 bit color map. Mcut
first quantizes intensity values from eight
bits to five bits, and then chooses the
colors from this space.
Mcut runs in two passes; the first pass scans
the image to find the color distributions,
and the second pass maps the original colors
into color map indices. The output file has
a color map containing the colors mcut has
chosen. Mcut also sets the picture comment
"color_map_length" equal to the number of
colors it has chosen. The getx11 program
(among others) will use this color map
instead of dithering.
OPTIONS
-n ncolors
Limit the number of colors chosen to
ncolors. The default is 200.
-d Uses Floyd/Steinberg dither to hide
contouring. Greatly improves images
that have a small number of colors.
infile
The input will be read from this file.
If it is a multi-image file, each image
will be quantized to its own colormap.
Piped input is not allowed.
-o outfile
If specified, output will be written to
this file, otherwise it will go to
stdout.
SEE ALSO
getx11(1), rlequant(1), urt(1), RLE(5),
"Color Image Quantization for Frame Buffer
Display", by Paul Heckbert, Procedings of
SIGGRAPH '82, July 1982, p. 297.
AUTHOR
Robert Mecklenburg, John W. Peterson,
University of Utah.
BUGS
The initial quantization is hardwired to five
bits. This should be an option.
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