Backward Adaptive Pre/Post-Filtered DPCM with Near-Optimal Rate-Distortion Performance

In this paper, we propose two backward adaptive coding algorithms based on a recently invented pre/post-filtered DPCM (Differential Pulse-Coded Modulation) codec. The pre/post-filters and the predictor are adapted jointly. Source statistics are assumed unknown a priori. One of the algorithms is based on power spectrum estimation, and the other gradient descent. Some properties of the algorithms are analyzed. Experiment results show that both algorithms achieve near-optimal rate-distortion performance, significantly outperforming the adaptive DPCM without adaptive pre/post-filtering.