FM SCREENING ACCOMPANYING SUB-DOT PHASE MODULATION

摘要

PROBLEM TO BE SOLVED: To prevent introduction of unfavorable artifacts in FM screening without introducing graininess on a halftone image. SOLUTION: A cluster of adjacent pixels can be arranged at any position on a pixel grid in an error diffusion half-toning process. A quantization step of the error diffusion takes an effect of an arrangement of the cluster of pixels into account. Dimensions of the pixel cluster can be fixed or variable. A quantization step of the half-toning process can take an effect of an arrangement of the cluster of pixels into account in the same or different color separation. The method generates less grainy halftone for steadily and uniformly printing in the presence of variation of the printer. A quantization step in the error diffusion process evaluates a quantization value of a possible alternative in arranging a cluster of a pixel. COPYRIGHT: (C)2004,JPO