Patent ID: 8194980

Claim:
A color gamut outline computing device comprising: a setting section that sets a single-color amount limit of at least one color material of device color signals of a device color space of four or more dimensions including black, an upper half color material total amount limit in an upper half region of the device color space, and a lower half color material total amount limit in a lower half region of the device color space; an upper half outline constructing section that constructs an upper half outline, the upper half outline being formed from outline points, that are points on a color gamut outline at which black is 0% and one or more color components other than black is 0% in the device color space, and that satisfy the single-color amount limit and the upper half color material total amount limit; an intermediate outline constructing section that constructs an intermediate outline by: (A) determining an intermediate color material total amount limit in an intermediate region that is between the upper half region and the lower half region, on the basis of the upper half color material total amount limit and the lower half color material total amount limit, and (B) deleting or correcting outline points, that are on a color gamut outline at which one or more color components other than black satisfy the single-color amount limit and one or more color components other than black is 0% in the device color space and that do not satisfy the intermediate color material total amount limit, to satisfy the intermediate color material total amount limit; a lower half outline constructing section that constructs a lower half outline, the lower half outline being formed from outline points, that are points on a color gamut outline at which the black color component satisfies the single-color amount limit and one or more color components other than black satisfy the single-color amount limit in the device color space, and that satisfy the lower half color material total amount limit; a restricting outline constructing section that constructs a restricting outline formed from outline points that satisfy the single-color amount limits, and satisfy at least one of the upper half color material total amount limit, the intermediate color material total amount limit and the lower half color material total amount limit, the outline points of the restricting outline being connected to outline points of at least one of the upper half outline, the intermediate outline and the lower half outline which satisfy at least one of the upper half color material total amount limit, the intermediate color material total amount limit and the lower half color material total amount limit; and a color space converter that converts outline points of the upper half outline, the intermediate outline, the lower half outline and the restricting outline into outline points of a color space other than the device color space.