Adaptive filtering for crossview prediction in multiview video coding We consider the problem of coding multiview video that exhibits mismatches in frames from different views. Such mismatches could be caused by heterogeneous cameras andor different shooting positions of the cameras. In particular, we consider focus mismatches across views, i.e., such that different portions of a video frame can undergo different blurrinesssharpness changes with respect to the corresponding areas in frames from the other views. We propose an adaptive filtering approach for crossview prediction in multiview video coding. The disparity fields are exploited as an estimation of scene depth. An Expectationmaximization (EM) algorithm is applied to classify the disparity vectors into groups. Based on the classification result, a video frame is partitioned into regions with different scenedepth levels. Finally, for each scenedepth level, a twodimensional filter is designed to minimize the average residual energy of crossview prediction for all blocks in the class. The resulting filters are applied to the reference frames to generate better matches for crossview prediction. Simulation results show that, when encoding across views, the proposed method achieves up to 0.8dB gain over current H.264 video coding.

Joint Trilateral Filtering for Depth Map Compression New data formats including 2D video and the corresponding depth maps enable new video applications in which virtual views can be rendered, such as 3DTV and freeviewpoint video (FVV). Different from video frames, depth maps typically consist of homogeneous areas (with no textures) separated by sharp edges representing depth value changes such as between foreground and background. Conventional video coding techniques with transforms followed by quantization typically result in large artifacts along such sharp edges. To suppress these coding artifacts while preserving edges, we propose in this paper a novel filtering method for depth coding, joint trilateral filter. The main contribution in the proposed filter design is the utilization of edge information in the collocated video frame as well as in the depth map. The filtering weights are determined by the following three factors: a domain (spatial) filter which measures the proximity of pixel positions, and two range filters. One range filter takes into account the similarity among depth samples and the other one considers the similarity among the collocated pixels in the video frame. By replacing the deblocking filter in H.264AVC with the proposed trilateral filter, simulation results demonstrate up to 0.8 dB gain in rendering quality at given bitrate for depth signal.