Joint Weighted Sparse Representation Based Median Filter for Depth Video Coding

In order to promote the development of auto-stereoscopic display, MPEG has proposed multi-view plus depth (MVD) format. The depth video is encoded and transmitted with color video to synthesize virtual views at the receiver side. The existing video coding standards such as H.264/AVC introduces coding artifacts along the depth boundaries, which may seriously affects the synthesized view quality and coding efficiency. Many in-loop depth filters such as joint depth filter have been proposed to remove the artifacts in compressed depth video. However, their performance is unstable and affected by the outliers due to the weighted summation. In this paper, based on the sparse prior characteristic in local region of depth map, we propose a joint weighted sparse representation based median filter to select the most relevant neighboring depth pixel as the output during the filter process. Experimental results show the proposed method is more effective in improving the depth video coding efficiency.