METHOD OF MANUFACTURING HALFTONE MASK, HALFTONE IMAGE, AND PRINTED MATTER

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a halftone mask which does not cause any moire, hexagonal pattern (Rosetta pattern), etc., and can make good ink transfer and with which halftone images having invariable density characteristic can be obtained, and to provide halftone images and printed matters using the mask. SOLUTION: The halftone mask is manufactured in such a way that random numbers are generated and stored in a memory correspondingly to pixels constituting mask blocks and spatial filtering is performed on the pass band corresponding to a set prescribed dot density and prescribed screen ruling. Then the pixel values of the mask blocks are replaced with the thresholds of the gradation ranges of bit numbers expressing the pixel values of an original image based on the cumulative distribution of the mask blocks obtained by digitization in absolute values. The halftone images and printed matters are obtained by using the mask.