JPH0137070B

PURPOSE:To reproduce beautiful colors by using a black plate on full-black basis, correcting a deficiency in gray reproduction density on the black plate with ink in three colors, and correcting the turbidity of the color ink. CONSTITUTION:An input device 10 inputs color separation signals R, G, and B of an original picture to an achromatic color separating circuit 11 to separate and extract maximum M among R, G, and B for forming the black plate K, thereby generating a full-black type K signal K=W-M. The RGB signal is converted by a color converting circuit 13 into an YMC system signal to obtain signals C2, M2, and Y2. The signal K, on the other hand, is sent to a memory 15 to read gray correcting data DELTAGC, DELTAGM, and DELTAGY, which are added by adders 16C, 16M, and 16Y to chromatic image signals C2' and M2' obtained by correcting turbid components of the C2, M2, and Y2, thus obtaining picture copy signals C3, M3, and Y3 of respective ink color plates. Thus, beautiful colors are reproduced.