.TH CMAP 9.6
.SH NAME
cmap \- color map format
.SH DESCRIPTION
A color map is a 256\(mu3-byte translation table for
color values.
In a monochrome picture, pixel values index
the color map to yield red, green and blue, like this:
.IP
.EX
unsigned char cmap[256][3];
red=cmap[pixel][0];
green=cmap[pixel][1];
blue=cmap[pixel][2];
.EE
.PP
In a full-color picture,
the color map is, in effect,
three intensity-compensation
tables:
.B cmap[red][0]
maps red channels,
.B cmap[green][1]
maps green channels
and
.B cmap[blue][2]
maps blue channels.
.PP
A colormap file is just a 768-byte file containing the color map,
stored in the order implied by the declaration of
.B cmap
above.