Halftone to continuous-tone conversion of error-diffusion coded images

摘要: In this chapter1 we consider the problem of reconstructing a continuos-tone (contone) image from its halftoned version, where the halftoning process is done by error diffusion. As there is a natural connection between error diffusion and ΣΔ modulation, the reconstruction technique developed in chapter 5 for one-dimensional signals readily generalizes to the image reconstruction problem. We present an iterative nonlinear decoding algorithm for halftone-to-contone conversion, and show simulation results that compare the performance of the algorithm to that of conventional linear lowpass filtering. We find that the new technique results in subjectively superior reconstruction.