INTERFRAME DPCM WITH ROBUST MEDIAN-BASED PREDICTORS FOR TRANSMISSION OF IMAGE SEQUENCES OVER NOISY CHANNELS

A new image sequence coding technique based on robust median-based pre dictors is presented for the transmission of image sequences over nois y channels, We analyze the robustness of median-based predictors again st channel errors. A heuristic algorithm for the design of a robust pr edictor from a given median-based predictor is presented, It is shown that with small modifications in terms of a necessary requirement for a median-based predictor to be robust against channel errors, the robu stness of a given median-based predictor can be considerably improved, Simulations on a real image sequence show significant improvement ove r the conventional differential pulse code modulation (DPCM) at high b it error rate (BER) using this new technique. The technique does not i ncrease the transmission rate. It is shown that the quality of reconst ructed images obtained by robust median-based predictors can be furthe r improved by postprocessing the image using a nonlinear detail-preser ving noise-smoothing filter.