Iterative Error Diffusion Halftoning Using a Zero Phase Error Filter

The halftone quality of an error diffusion halftone depends on the error filter response. Apart f o rm the magnitude response being a low pass, it is desirable to have a zero phase response. In this paper we propose the iterative error diffusion halftoning algorithm that allows use of non-causal error filter (such as zero phase error filter). W e present simulation results showing that the proposed halftoning scheme is substantially better, specially in retaining the sharpness of the edges and in truthfullness.