Research On Raster Image Processing System Of Digital Printing

Raster image processing system is a vital part of digital printing. Screening technology is one of key technologies in raster image processing, it relates to output quality and speed of the printing system. This paper analyzes the workflow of the raster image processor and the description of principles and methods of PostScript page description language. The existing screening technology at home and abroad and the factors that affect the screening technology are discussed. The new methods or techniques are based on helical scan & optimal threshold error diffusion algorithm, which greatly improved the quality of the image reproduction. Introduce pixel dynamic error diffusion halftoning based on HVS model and edge detection, to improve loses of detail outline of image processed in the conventional error diffusion method. Experiments had improved that new methods are superior to existing digital halftoning methods in aspect of subjective sense and objective evaluation.