JPS6454972A - Color converting circuit - Google Patents

Abstract

PURPOSE:To attain efficient coding by providing a conversion table circuit for rescaling in response to a color signal and rescaling of a lightness signal to a pre-stage of a reference table inputting the color signal to output an incor porated color signal so as to decrease the increase of a table capacity. CONSTITUTION:A high-order 4-bit L* signal and an 8-bit a* signal are given to a reference table 11 of the pre-stage conversion of a color conversion circuit to output the a*' signal scaled-down to 6-bit. Moreover, the high-order bit of L* signal and the 8-bit b* signal are inputted to a reference table 12 to output the 6-bit b*'' signal. The output from the tables 11, 12 and the high-order 4-bit L* signal are inputted to a reference table 13 for conversion at the post-stage to output coded a*b* signals in 10-bit. Then one or other scale of the color component is converted in response to the light component by the tables 11,12 respectively in the pre-stage conversion and the table 13 incorporates the color component.