Wyner-ziv Video Coding with Low Encoder Complexity

In current interframe video compression systems, the encoder performs predictive coding to exploit the similarities of successive frames. The Wyner-Ziv Theorem on source coding with side information available only at the decoder suggests that an asymmetric video codec, where individual frames are encoded separately, but decoded conditionally (given temporally adjacent frames) could achieve similar efficiency. In previous work we proposed a Wyner-Ziv coding scheme for motion video that uses intraframe encoding, but interframe decoding. In this paper we improve on our Wyner-Ziv video codec by run-length coding high frequency coefficients and using these coefficients at the decoder to accurately estimate the motion. This allows us to implement a low-delay system where only the previous reconstructed frame is used to generate the side information of a current frame. Simulation results show significant gains above conventional DCT-based intraframe coding. The proposed Wyner-Ziv video codec enables low-complexity encoding while achieving high compression efficiency.