What is the difference between perceptual colour gamut mapping and categorical colour gamut mapping?
These terms can mean different things to different people. However, in general you could think of categorical color gamut mapping as one form of perceptual color mapping. Categorical color mapping aims to make sure that colors in the reproduction do not cross color-naming category boundaries defined typically according to the 11 basic color terms of Berlin and Kay (white, gray, black, red, green, blue, yellow, purple, pink, orange, brown). Presumably, if the colors all remain in the same categories, the reproduction will approximately match the original perceptually. Perceptual color gamut mapping tries to best reproduce the appearances of the original image by minimizing changes in some color space such as CIELAB. Generally some rules are adopted to set priorities for the distributing the necessary errors (e.g., preserve hue, use a sigmoidal lightness mapping, and clip chroma). A more general perceptual gamut mapping algorithm wouldn’t specifically concern itself with color-naming cat
