Patent ID: 6396595
Filing Date: 2002-05-28
Classification: H04N

Abstract:
A method of generating color conversion data to convert color image data C, M, Y, K which are used to produce a printed material into color image data Câ€², Mâ€², Yâ€², Kâ€² which are used in a color output apparatus to equalize the colors of the printed material with the colors of a color image produced by the color output apparatus, comprising the steps of:establishing a relationship K=f(C, M, Y) for determining color image data K from image data C, M, Y; determining color conversion data to equalize colors of a printed material based on color image data C, M, Y, f(C, M, Y) with colors of a color image outputted by said color output apparatus based on color image data Câ€², Mâ€² Yâ€², Kâ€²; determining one-dimensional color conversion characteristics Kâ€²=Rk(K) to equalize colors of a printed material based on monochromatic color image data K with colors of a color image outputted by said color output apparatus based on monochromatic colors image data Kâ€²; determining three-dimensional color conversion characteristics j=Rj(C, M, Y) (j=Câ€², Mâ€², Yâ€²) to convert the color image data C, M, Y into the color image data Câ€², Mâ€², Yâ€² to equalize colors of a printed material based on color image data C, M, Y, f(C, M, Y) with colors of a color image outputted by said color apparatus based on color image data Câ€², Mâ€², Yâ€², Rk(f(C, M, Y)); converting color image data C, M, Y, K into color image data Câ€², Mâ€², Yâ€², Kâ€² using color conversion data of said three-dimensional color conversion characteristics j=Rj(C, M, Y) (j=Câ€², Mâ€², Yâ€²) and said one-dimensional color conversion characteristics Kâ€²=Rk(K); establishing a relationship K1=f1 (C, M, Y) to determine color image data K1 and a relationship K2=f2 (C, M, Y) to determine color image data K2, the color image data K1, K2 being related to color data image Kreal according to a relationship K1real2; determining three-dimensional color conversation characteristics j1=Rj1 (C, M, Y) (j1=Câ€², Mâ€², Yâ€²) to convert color image data C, M, Y, f1 (C, M, Y) into color image data Câ€², Mâ€², Yâ€²; determining three-dimensional color conversion characteristics j2=Rj2 (C, M, Y) (j2=Câ€², Mâ€², Yâ€²) to convert color image data C, M, Y, f2 (C, M, Y) into color image data Câ€², Mâ€², Yâ€²; determining one-dimensional color conversion characteristics Kâ€²=Rk1 (K1) to convert color image data K1 into color image data Kâ€²; determining one-dimensional color conversion characteristics Kâ€²=Rk2 (K2) to convert color image data K2 into color image data Kâ€²; and determining three-dimensional color conversion characteristics j=Rj (C, M, Y) (j=Câ€², Mâ€², Yâ€²) and one-dimensional color conversion characteristics Kâ€²=Rk (K) according to: j=Rj(C, M, Y)=(1âˆ’t)Â·Rj1+tÂ·Rj2 Kâ€²=Rk(K)=(1âˆ’t)Rk1+tÂ·Rk2 where t is a parameter expressed by t=(Krealâˆ’K1)/(K2âˆ’K1).