Patent ID: 6499829
Filing Date: 2002-12-31
Classification: H04N

Abstract:
A color image forming apparatus comprising:a black-coloring processing portion for decomposing first color image signals each corresponding to one of multiple colors into second color signals and a black signal, and an output section for outputting the second color signals and the black signal as a color image using chromatic color materials and a black color material, and wherein the black-coloring processing portion decomposes the first color signals into the second color signals and the black signal in accordance with K=f(min(I)) A=h(I)âˆ’j(g(min(I))) B=i(I)âˆ’k(g(min(I))) Iâ€²=AÃ·B(Aâ‰ B or Bâ‰ 0) where K is the black signal, I is the first color signals, Iâ€² is the second color signals, min(I) is the minimum among the first color signals, f(min(I)) is a function of min(I), g(min(I)) is a function of min(I), h(I) is a function of I, i(I) is a function of I, j(g(min(I))) is a function of g(min(I)), and k(g(min(I))) is a function of g(min(I)).