NEW EDGE-ENHANCED ERROR DIFFUSION ALGORITHM-BASED ON THE ERROR SUM CRITERION

A new edge-enhanced error diffusion algorithm, based on Eschbach's alg orithm, is proposed. Thick-edged artifacts as well as small edge-enhan cement effects for the bright or dark pixel values are observed in the previous algorithm. By analyzing the phenomena, a new improved algori thm is proposed by using the diffused error sum and input pixel value. An input pixel is classified into a normal- or edge-region pixel base d on the error sum criterion. A new error calculation is then employed for the edge-region pixel, while conventional error calculation is us ed for the normal-region pixel. The proposed method requires only a fe w additional calculations and provides edge-enhanced binary output ima ges. The edges are influenced less by the brightness offset, and thick -edged artifacts are reduced.