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) 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.
SEE ALSO
picfile(9.6)