term% cat index.txt CMAP(9.6) CMAP(9.6)
NAME
cmap - color map format
DESCRIPTION
A color map is a 256×3-byte translation table for color values. In a
monochrome picture, pixel values index the color map to yield red,
green and blue, like this:
uchar cmap[256][3];
red = cmap[pixel][0];
green = cmap[pixel][1];
blue = cmap[pixel][2];
In a full-color picture, the color map is, in effect, three intensity-
compensation tables: cmap[red][0] maps red channels, cmap[green][1]
maps green channels and cmap[blue][2] maps blue channels.
A color map file is just a 768-byte file containing the color map,
stored in the order implied by the declaration of cmap above.
CMAP(9.6)