Analysis of Color Error Diffusion with Vector Error Filters

摘要

As vector error filters are capable of passing errors generated in one color component to other color components, it provides more flexibility in shaping the halftone texture. As a result, it may potentially produce halftones with better image quality. In this paper, we analyze color error diffusion with vector error filters. In particular, we will discuss its halftone spectrum features and its stability conditions with respect to the filter coefficients. For spectrum analysis, we will derive the high-pass and average color preservation conditions, which ensure decent image quality. Since error diffusion is a feedback system, the vector error filters may cause instability, if it is not properly designed. This may potentially generate ever-increasing quantization error that masks the input and produces unacceptable output images. The stability conditions we will discuss provide guidelines for designing stable systems.