Fast Motion Estimation-Based Reference Frame Generation in Wyner-Ziv Residual Video Coding
In practical Wyner-Ziv video coding, every frame is encoded independently of others, but decoded based on the side information generated from adjacent frames. In Wyner-Ziv residual coding of video, the residual of a frame with respect to a reference frame is Wyner-Ziv encoded, which leads to a higher coding efficiency than directly Wyner-Ziv encoding the original frame. In previous work, the reference frame is directly copied from the previously reconstructed frame. In this paper, we generate the reference Wyner-Ziv frame at the encoder using low complexity fast motion search. Experimental results show that the proposed scheme provides a significant gain in video coding efficiency with the encoding complexity being only slightly increased. Using our approach, Wyner-Ziv residual video encoding becomes flexible and allows us to trade-off the encoding complexity and the overall rate-distortion performance. Moreover, the reference frame can help us in refining the side information generated at the decoder, which contributes to the improvement of the overall video coding efficiency.