[comp.graphics] Color Approximation

mlp@dana.UUCP (Mark Patrick) (09/04/87)

I would like to here from anyone with experience in outputing full color
graphics to pseudo color devices, and any reactions people have to the
current xphigs and phigs+ proposals.  I am primarily interested in techniques
for specifying the appropriate color in which to draw geometry (points, lines, 
polygons etc.) using available graphics hardware.  The three major classes
of techniques I know of are:  allocation of a specific number of bits of the
color index for each of r, g and b (e.g. 3-3-2 on an 8 bit device); 
partitioning of the color lookuptable into shade ranges one for each major
color in the image and use of the intensity information produced by the
renderer to select a color from the current shade range; dithering techniques.
Which techniques have you used, what are the advantages and disadvantages of
each kind, what do you like to use, should more than one technique be provided,
what other techniques are there.

Thanks for any input

Mark Patrick
hplabs!dana!mlp