Distortion Analysis of Wyner-Ziv Distributed Video Coding

The Distributed Video Coding (DVC) follows an approach different from the conventional video coding. DVC has a simpler encoder but a more complicated decoder. This feature makes it possible to encode video in computation and energy constrained devices. Thus, DVC is appealing in sensor networks and other wireless networks. When transmitting real-time DVC encoded video streams, in order to adjust coding parameters according to the time-varying communication channel conditions or the dynamics of available bandwidth in the bottleneck, the source needs an efficient way to know the tradeoff of the coding parameters and the decoded video quality. However, how to quantify the DVC video quality using tractable models is an open issue. In this paper, we propose a distortion analysis model for DVC encoded Wyner-Ziv frames. The proposed closed-form distortion model for Wyner-Ziv frames is based on the reconstruction method of the "nearest neighbor binning". With the distortion analysis model, the average video frame PSNR can be estimated as a function of the codec parameters and the video statistics. Extensive simulations with different types of videos have been conducted and the results validate the accuracy of the proposed model. The model will be an enabling tool to further optimize the system parameters and network protocols for supporting DVC coded video over wireless and wired networks.