Low Complexity Spatio-Temporal Key Frame Encoding for Wyner-Ziv Video Coding

In most Wyner-Ziv video coding approaches, the temporal correlation of key frames is not exploited since they are simply intra encoded and decoded. In this paper, using the previously decoded key frame as the side information for the key frame to be decoded, we propose new methods of coding key frames in order to improve the rate distortion performance. These schemes which are based on switching between intra mode and Wyner-Ziv mode for a given block or a given frequency band attempt to make use of both spatial and temporal correlation of key frames while satisfying the low complexity encoding requirement of distributed video coding (DVC). Simulation results show that using the proposed methods, one can achieve up to 5 dB improvement over conventional intra coding for relatively low motion sequences and up to 1.3 dB improvement for relatively high motion sequences.