Gamut mapping utilizing cusp points and three-dimensional boundary surfaces

摘要

Gamut-mapping from a source device to a destination device is performed in a perceptually linear color space such as CIECAM02 by separating a source image into primary color components and processing each primary component separately by mapping a source cusp point with a destination cusp point. The mapped primary components are then summed and a resultant destination image is obtained. Alternatively, hue rotation is performed by determining a relative position of an input color between the nearest primary and the nearest secondary color in a source hue wheel. The determined relative position in the source hue wheel is used to find a corresponding location in a destination hue wheel so that a hue angle for the destination point can be obtained. In either process, the source and destination points are mapped using a cusp-to-cusp mapping process, and if the source point lies outside of the destination boundary after the cusp mapping, the point is mapped to the three-dimensional surface of the destination gamut. Finally, results of the mapping process are converted from device-independent color appearance space values to tristimulus values, and from tristimulus values to a color space of the destination device.