| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform such color conversion as to maintain gradations without inverting a saturation when converting an input color signal into a color signal suitable for an output device. <P>SOLUTION: A first color converter 12 converts an RGB signal input from a line input unit 11 into an L*a*b* signal, a brightness range compressing unit 13 matches a brightness range of the input color signal to a brightness range of an output gamut and when a peak saturation point in an input line is out of the output gamut, an input line correction unit 14 performs such correction as to map the peak saturation point onto an output gamut surface. If a surface vicinity decision unit 15 determines that a correction line is not positioned in the vicinity of the surface of the output gamut, an out-of-gamut mapping unit 17 performs mapping to the output gamut surface and if it is determined that the correction line is positioned in the vicinity of the surface, a surface mapping unit 16 maps all the points onto the output gamut surface. A second color converter 18 then converts the mapped L*a*b* signal into a CMYK signal. <P>COPYRIGHT: (C)2010,JPO&INPIT |
