Patent ID: 8804193

Claim:
A color conversion device comprising a grid point arranging part which arranges, between an input device represented by three values of RGB and an output device represented by four values of CMYK, grid points as correspondence of the RGB value of the input device and the CMYK value of the output device equally in a radial direction from a prescribed achromatic color axis to generate a radial color conversion table; a color conversion table restructuring processing part which stacks, in the order of hue, a hue layer consisting of a surface of a hue and a surfaced of its complementary hue of the radial color conversion table to generate an orthogonal grid color conversion table in which the grids form an orthogonal grid; an image information input part which inputs image data of RGB format; and a color conversion processing part which converts the input image data of RGB format into image data of CMYK format by means of the orthogonal grid color conversion table; wherein, the grid point arranging part, in color conversion from the RGB value to the CMYK value, divides the line RdYe, the line YeGr, the line GrCy, the line CyBl, the line BlMg, and the line MgRd of the orthogonal grid having Rd (red), Gr (green), Bl (blue), Cy (cyan), Mg (magenta), Ye (yellow), Wh (white) and Bk (black) as the vertex into N equal parts (N is a positive integer) to generate a predetermined color region chroma edge points, divides the color region chroma edge points into the combination of the chroma saturation point P and the chroma saturation point P′ which satisfy the complementary color relationship, generates a radial color conversion table by arranging the above-mentioned grid point at an intersection obtained by dividing the line BkP and the line BkP′ of a square part formed of BkPWhP′ which is formed for each combination into 3N equal parts, and the color conversion reorganization processing part generates an orthogonal grid color conversion table in which the grid forms an orthogonal grid by stacking, in the order of hue, a hue layer consisting of a surface of a hue and a surface of its complementary hue of the radial color conversion table.