ERROR DIFFUSION METHOD AND ERROR DIFFUSION SYSTEM AND MULTILEVEL PIXEL BINARY METHOD

摘要

PROBLEM TO BE SOLVED: To optimize picture quality for image characteristics of different types and all image types by diffusing an error generated when a gray level value representing a pixel is processed with a threshold value. SOLUTION: A distribution coefficient memory 4 is stored with various groups of weighting coefficients used for an error diffusing process. The groups are determined according to receive information from an error diffusion decoder 7. Namely, the groups are selected on the basis of an image type and image characteristics of a pixel to be processed. In response to the receive information from the error diffusion decoder 7, the distribution coefficient memory 4 loads the properly selected group of weighting coefficients to a threshold processing circuit and an error diffusing circuit 5 including an error distribution circuit distributing the error in relation to it, so a proper error term is propagated to a downstream pixel. Further, the error diffusing circuit 5 outputs image data which can be rendered on an output device.