An Approach to Side Information Estimation for Wyner-Ziv Video Coding

In the new video coding paradigm, Wyner-Ziv (WZ) video coding, or lossy coding of video with decoder side information (SI), SI is involved not only in the decoding of the quantized source, but also in the reconstruction process, so the quality of SI is a key factor to the performance of a WZ video codec. In this paper, an approach to SI estimation for WZ video coding is proposed. It is based on motion compensated temporal interpolation. In the approach, stationary areas are first identified by motion detection. Nearly textureless areas for which motion vectors can not be reliably estimated with smaller block size are also identified by the analysis of spatial intensity gradients. Based on the identification of such areas and on the matching errors of the estimated motion vectors, a variable size block based motion field is then estimated using a splitting strategy. Post-processing of the estimated motion vectors is also conducted to deal with blocks which may still contain more than one objects with different motion. The performance of the proposed approach is evaluated in the context of WZ video coding, and compared with some existing methods. The simulation results verify the effectiveness of the propose approach.