Wyner-Ziv video coding based on a new hierarchical block matching algorithm

Abstract

Distributed video coding (DVC) is a new video coding paradigm that shifts the complexity from the encoder side to the decoder side. One particular case of DVC, the Wyner-Ziv coding scheme, encodes each video frame separately and decodes the video sequence jointly with side information. This paper presents a new Wyner-Ziv video coding scheme based on hierarchical block matching algorithm (HBMA). In this proposed scheme, the side information is greatly refined to assist the reconstruction of the Wyner-Ziv frames. The bidirectional motion estimation and the forward motion estimation are associated to generate the interpolated frame from temporally adjacent key frames to attain the high fidelity side information. During the bidirectional motion estimation, the size of the block and the search area vary at different levels of hierarchy. In additional, the motion vectors are inherited from big blocks to small blocks by choosing the smallest mean-of-the-absolute-difference value among neighboring blocks. Preliminary experiment results show that the proposed scheme can achieve better rate-distortion performance by 0.5-1 dB compared to the existing Wyner-Ziv video coding with the slightly increased decoding complexity.