Patent ID: 7123391

Claim:
A color image processing apparatus for performing color separation to separate image data colors into primary four color-material colors and pale color-material colors of predetermined ones of the primary color-material colors, comprising: setting means for setting a target gray line connecting white to black for the color separation in predetermined color space; three color gray generation means for obtaining a combination of three color materials to realize a color on the target gray line; four color separation processing means for determining amounts of the primary four color materials to realize the color on the target gray line; total color material amount determination means for determining a total color material amount to realize the target gray line; and color-material amount determination means for, regarding a color which cannot be realized by the combination of primary Y color and the pale color-material colors to realize the color on the target gray line, determining respective color material amounts of the color materials based on the total color material amount and the color material amounts of the primary four colors.