QUANTIZE(9.1) QUANTIZE(9.1)
NAME
3to1, mcut, improve, quantize, dither - picture color
compression
SYNOPSIS
fb/3to1 [ -e ] colormap [ input ]
fb/mcut [ input ]
fb/improve colormap [ input ]
fb/quantize [ input ]
fb/dither [ input ]
DESCRIPTION
3to1 approximates the full color (3 bytes per pixel) or
mapped (1 byte per pixel, possibly with a colormap) input
picture file in one byte per pixel using the given colormap.
If no input file is named, the picture is read from standard
input. The -e option suppresses the default error-diffusion
dither.
Mcut writes a color map, suitable for use by 3to1 on its
standard output. The color map is computed using the
median-cut algorithm and represents reasonably well, but not
necessarily optimally, the colors of the input picture.
Improve reads a color map and a picture and writes on stan-
dard output a new color map that better represents the col-
ors of the picture. Multiple passes of improve may produce
better and better color maps.
Quantize is an rc script that packages all of the above to
compress the full-color input image to one byte per pixel.
Dither likewise compresses full-color images to one byte per
pixel. It uses a fixed color map that allows a speedy algo-
rithm; quantize instead runs slower but gives better
results.
SOURCE
/sys/src/fb/3to1.c
/sys/src/fb/mcut.c
/sys/src/fb/improve.c
/sys/src/fb/quantize.r
/sys/src/fb/dither.c
SEE ALSO
picfile(9.6), cmap(9.6)
Page 1 Plan 9 (printed 12/21/24)
QUANTIZE(9.1) QUANTIZE(9.1)
Page 2 Plan 9 (printed 12/21/24)