Content adaptive depth map resampling scheme in multiview video plus depth

In this paper, we propose a content-adaptive pre-processing for downsampling depth map for 3D multiview plus depth video coding. The proposed scheme takes advantage of spatially varying content of depth maps and targets improved encoding performance. The key idea is to divide the video frames into several horizontal and vertical stripes and downsample each of them with an appropriate downsampling ratio. With this approach, the rectangular shape of the frames are preserved, hence the video sequence can be coded with a standard encoder. The downsampling ratios, defined for each Intra period, are determined via a Rate Distortion Optimization process. Simulation results show that the proposed method outperforms the reference in which no downsampling is used by 0.35dB of Bjontegaard delta Peak Signal-to-Noise Ratio (PSNR) and brings up to 31% and average of 18% of Bjontegaard delta bitrate reduction (dBR).