Color Compression Software Available

[Shijie Wan]

	Color Compression Software Available
	------------------------------------
A full-color image can use up to 16 million different colors.  Most
commonly used color monitors and laser printers can display/print only 256
or less different colors simultaneously.  In order to display/print a
full-color image on these devices, the number of colors in the original
image must be compressed before display. 

We have designed a color image quantization algorithm which can reduce the
colors in a full-color image to 256 colors or less with minimum
distortion. Experiments show that in most cases our algorithm needs to use
128-256 colors to produce an image which looks almost identical to the
original full-color image.  With 32-64 colors, it can produce images of
high quality.  For 32 colors or less, it can generate quantized images
with minimum contouring effects, with the aid of dithering techniques.
For details of the algorithm and image examples, read the paper:

	S.J. Wan, P. Prusinkiewicz, and S.K.M. Wong, Variance-based 
	color image quantization for frame buffer display, Color 
	Research and Application, vol. 15 (1), pp. 52-58, Feb. 1990.

The program is written in C for Silicon Graphics IRIS machine.  Versions
for other machines running UNIX are also available.  Excluding the time
for image disply, the program needs about 10-40 seconds to process one
image. For more information, please contact:

|   wan at mercury.uregina.ca   |    Shijie Wan                   | 
|   Tel: (306)-584-5717      |    Dept. of Comp. Sci.          |
|        (306)-585-4690      |    Univ. of Regina              |
|   Fax: (306)-584-5717      |    Regina, Sask.                |
|                            |    Canada S4S 0A2               |