Color separation into a plurality of ink components including primary color ink and spot color ink

摘要

Utilizing an ink set that includes a plurality of chromatic primary color inks that, when used in combination, can reproduce achromatic color, and at least one spot color ink of hue different from any of the plurality of chromatic primary color inks. Color to be reproduced on a print medium according to any one input color is termed “reproduction color”, and the combination of ink quantities in the ink set for reproducing the reproduction color on the print medium is termed the “color separation ink quantity set.” The ink quantity of the spot color ink included in the color separation ink quantity set is adjusted in accordance with a lightness parameter value which is correlated to lightness of reproduction color, so as to reduce ink quantity at a rate of change greater than the rate of change of the lightness parameter in the direction of increasing brightness.