摘要 |
In addition to linear conversion parameters V1 to V8 which are used in an interpolation calculation, non-linear conversion parameters VV1 to VV8 are calculated. Each time an input color is fetched, whether the linear conversion parameters are used or the non-linear conversion parameters are used is discriminated. The interpolation calculation of a high precision using the non-linear conversion parameters is performed for a region where it is necessary to guarantee a gradation, thereby preventing a reversal of an output color in a region including an achromatic gradation axis. Regions other than such a region are processed by the interpolation calculation using the linear conversion parameter at a high speed. <IMAGE> |