Gamut reduction

Gamut reduction is the process of converting an image into another image using a different set of colours.

When the convex hull of the destination palette contains all the colours of the source image, standard multi-colour dithering can be applied. This is always the case when the destination palette contains the 8 Neugebauer primaries, but it otherwise depends on the source image.

We’re interested in a more generic approach: creating a continuous mapping between the RGB cube (or the corresponding colour solid in the current colourspace) and the convex hull of the destination palette. We need to handle cases where only 2 colours are available, or where even black and white are not available.

Bibliography

• [1] S. Chosson, R.D. Hersch. "​Techniques for Color-Gamut Reduction", SPIE’s International Technical Group Newsletter, Electronic Imaging 13.2, June 2003, 5-8
• [2] S. Chosson, R.D. Hersch. "​Color Gamut Reduction Techniques for Printing with Custom Inks", Conf. Color Imaging: Device-Independent Color, Color Hardcopy, and Graphic Arts VII, 2002, SPIE Vol. 4663, 110-120
• [3] E.J. Stollnitz, V. Ostromoukhov, D. Salesin. "​Reproducing Color Images Using Custom Inks", Proc. SIGGRAPH 98, in Computer Graphics Proceedings, Annual Conference Series, 1998, 267-274