.TH QUANTIZE 9.1.SH NAME3to1, mcut, improve, quantize, dither \- picture color compression.SH SYNOPSIS.B fb/3to1[.B -e].I colormap[.I input].PP.B fb/mcut[.I input].PP.B fb/improve.I colormap[.I input].PP.B fb/quantize[.I input].PP.B fb/dither[.I input].SH DESCRIPTION.I 3to1approximates the full color (3 bytes per pixel) or mapped (1 byte per pixel,possibly with a colormap) input picture file inone byte per pixel using the given.IR colormap .If no.I inputfile is named, thepicture is read from standard input.  The.B -eoption suppresses the default error-diffusion dither..PP.I Mcutwrites a color map, suitable for use by.I 3to1on its standard output.  The color mapis computed using the median-cut algorithmand represents reasonably well, but notnecessarily optimally, the colorsof the input picture..PP.I Improvereads a color map and a picture and writeson standard output a new color map that betterrepresents the colors of the picture.Multiple passes of.I improvemay produce better and better color maps..PP.I Quantizeis an.I rcscript that packages all of the above to compress the full-colorinput image to one byte per pixel..PP.I Ditherlikewise compresses full-color images to one byte per pixel.It uses a fixed color map that allows a speedy algorithm;.I quantizeinstead runs slower but gives better results..SH SOURCE.B /sys/src/fb/3to1.c.br.B /sys/src/fb/mcut.c.br.B /sys/src/fb/improve.c.br.B /sys/src/fb/quantize.r.br.B /sys/src/fb/dither.c.SH "SEE ALSO.IR picfile (9.6),.IR cmap (9.6)