US Patent 7821659 Image processing method and image processing device

When there is an object of a color plate which is different than a process color, it is confirmed whether or not Color (n), which corresponds to that color name Spot (n), is a spot color. If Color (n) is a spot color, CMYK value conversion is carried out from a LUT of that spot color, and CMYK values are composed in a region for output. If Color (n) is a process color, CMYK values thereof are stored in a region for CMYK color correction. After color correction is carried out on the CMYK values of the region for CMYK color correction, they are composed with CMYK values of the region for CMYK output. Color information when a color plate different than a process color is included, is generated.