Method and device for converting color signal

摘要

Described is a method and a device for converting a color signal consisting of a plurality of chromatic color components into another color signal consisting of the plurality of chromatic color components and an achromatic color component. Firstly, an achromatic value is obtained, and then an under color addition is executed to obtain a chromatic value for each of the plurality of chromatic color components. Then, whether the chromatic values for the plurality of chromatic color components should be replaced with predetermined values is examined. If it is determined that the chromatic values for the plurality of chromatic color components should be replaced with predetermined values, the chromatic values are replaced with the predetermined values, and the another color signal consisting of the chromatic color components having the chromatic values and the achromatic color component having the achromatic value is output as the converted signal.