Abstract
Aspiring to provide robust low-complexity encoding for video, this work presents a hash-based transform domain distributed video codec, featuring a novel maximum likelihood motion compensation technique to generate high quality side information at the decoder. A simple hash is employed to perform overlapped block motion estimation at the decoder, which produces a set of temporal predictors on a pixel basis. For every pixel position, maximum likelihood motion compensation, based on an online estimate of the conditional dependencies between the temporal predictors and the original frame, combines the cluster of temporal predictors into a single value to serve as decoder-generated side information. Efficient low-density parity-check accumulate channel codes refine the side information in the transform domain. Experimental results demonstrate that the proposed system advances over our previous hash-based distributed video coding architectures, delivering state-of-the-art distributed coding performance, in particular for sequences organized in large groups of pictures or containing highly irregular motion. Notwithstanding the presence of a hash, the presented distributed video codec successfully maintains low encoder complexity.