Patent ID: 7843606

Claim:
A color converter comprising: a setting section that sets a ratio between a plurality of color rendering intents; a determining section that determines a color conversion function for converting a first image signal in a first color space into a second image signal in a second color space different from the first color space, based on the ratio between the color rendering intents; and a converting section that converts the first image signal into the second image signal based on the color conversion function determined by the determining section, wherein the determining section determines the color conversion function for a gamut compression/decompression element when the color conversion function based on the ratio between the color rendering intents is not stored, the setting section can store the determined color conversion function with a name, the gamut compression/decompression element comprises at least one of brightness and saturation compression ratio, hue shift amount, gradation number in a hue direction, brightness shift amount, or saturation gradation number, the brightness and saturation compression ratio and the saturation gradation number is based on L′out=L′in×(Lout1/Lin1) f(x) and f(x)=(L′in/Lin1) Cn11 , where Cn11 is a first compression coefficient, L′out is a distance from an achromatic color point to the second image signal, L′in is a distance from the achromatic color point to the first image signal, Lout1 is a distance from the achromatic color point to an outer point of a color gamut of the second image signal, and Lin1 is a distance from the achromatic color point to an outer point of a color gamut of the first image signal, the hue shift amount is based on Cout=Cin1−Cdif×(Cdata/Cmax1) Cn12 , where, Cout is a hue angle of the second image signal, Cin1 is a hue angle of the first image signal, Cdif is a maximum saturation-hue shift amount, Cdata is a saturation in the first image signal, Cmax1 is a saturation of a maximum saturation point, Cn12 is a second compression coefficient, and the brightness shift amount is based on Lout2=Lin2−Ldif×(Cin2/Cmax2) Cn13 , where Lout2 is a brightness value after conversion, Lin2 is a brightness value before conversion, Ldif is a brightness adjustment value, Cin2 is a saturation in the first image signal, Cmax2 is a saturation of the maximum saturation point, and Cn13 is a third compression coefficient.