Patent ID: 6995881

Claim:
An image processing method for determining a starting point which produces a black component between vertices showing a plurality of chromatic colors and a vertex showing a black in a reproducible color space of a color output apparatus, an amount of the black component between the starting point and the vertex showing the black and an amount of a complementary color component, when a look-up table for converting an input color signal into a plurality of color components including a black component is prepared, said method comprising the steps of: determining the starting point which produces the black component based on the value of the complementary color component corresponding to the chromatic color which is inconspicuous in a graininess of a black recording material in an output image; determining the amount of the black component between the starting point and the vertex showing the black by linearly increasing the black component from the starting point to the vertex showing the black, independently of the complementary color component corresponding to the chromatic color; and determining the amount of the complementary color component based on the determined amount of the black component.