Dither mask creating method and creating device

摘要: In a computer generation of dither mask for conversion continuous-tone image into halftone image, pixel array having size in accordance with the is partitioned blocks. Initial values are determined such that occurrences will be substantially uniform A pair exchange target pixels selected at random from one blocks and function predetermined evaluation indicates characteristic value configuration this block computed two cases where exchanged among not exchanged. These compared to judge whether should performed.