METHOD FOR FORMING ADDITIONAL COLOR IN HALF-TONE COLOR PICTURE OBTAINED BY OVERLAPPING HALF-TONE DOT OF ORIGINAL COLOR, WHOSE SIZE IS CHANGED

摘要

PURPOSE: To simulate a special color which cannot be directly reproduced in a digital color correction device (DDCP) with only primary colors (for example, cyan, magenta, yellow, and black). CONSTITUTION: Dot sizes of half-tone dots 110, 120, 130, and 140 of various primary colors are changed together with the density of a solid part, and dots are overlapped by alignment in so called the dot-on-dot form to generate mimic colors in a wide range which simulate the special color. Dot gains and a density look-up table are properly used to transform connective gradation values and data made into a bit map, and the dot size of half-tone dots of each primary color and the density of the solid part are changed, and thereafter, a correction engine is used to print these dots. Special tables are used for generation of various colors respectively.