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mcut - Quantize colors in an image using the median cut algorithm
mcut [ -n colors ] [ -d ] [ -o outfile ] infile
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.
- -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.
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.
Robert Mecklenburg, John
W. Peterson, University of Utah.
The initial quantization is hardwired
to five bits. This should be an option.
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