Patent ID: 7692663

Claim:
Method in a computer for constructing a multi-shelled gamut boundary descriptor (GBD) for an RGBW self-luminous display device which projects a white light W brighter than additive RGB white, wherein there is a device model for the self-luminous display device which defines a relationship between color values in a device dependent RGB color coordinate system and corresponding color values in a device independent color coordinate system, and wherein the multi-shelled GBD comprises at least an outer shell and an inner shell, said method comprising: using the computer to construct the outer shell of the multi-shelled GBD by transforming a unit cube in the RGB color coordinate system into a perceptual color space, and using the computer to construct the inner shell of the multi-shelled GBD by transforming an irregularly-shaped inner cube in the RGB color coordinate system into the perceptual color space, wherein the irregularly-shaped inner cube in the RGB color coordinate system is defined by eight reference primaries that define vertices of the irregularly-shaped cube, and wherein one of the vertices of the irregularly-shaped inner cube from which the inner shell of the multi-shelled GBD is constructed corresponds to the additive RGB white.