| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve color conversion with high accuracy by a smaller quantity of operation processing compared with the case that shift operation is performed to all terms after multiplication of a conversion coefficient and the case that shift operation is performed in a block after addition of all terms to which the multiplication of the conversion coefficient is performed. <P>SOLUTION: A secondary term generation unit 20 calculates secondary terms (BB, GG, RR, BG, GR, and GB) from three color components of RGB image data. Shift operation units 31-36 shift values of the six secondary terms by a bit number that is set by pre-shift amounts Sbb, Sgg, ..., and Srb, respectively. Multipliers 41-49 multiply values (B, G, and R) of the three color components and values after shift operation by nine conversion coefficients C1-C9, respectively. An adder 50L adds the multiplication results of the nine multipliers 41-49. A shift operation unit 60L shifts the added value by a bit number of a common shift amount SL and outputs the shifted value as a value of an L* component. <P>COPYRIGHT: (C)2013,JPO&INPIT |
