Model-based intra coding for depth maps in 3D video using a depth lookup table

3D Video is a new technology, which requires the transmission of depth data alongside conventional 2D video. The additional depth information allows to synthesize arbitrary viewpoints at the receiver and enables adaptation of the perceived depth impression and driving of multi-view auto-stereoscopic displays. In contrast to natural video signals, depth maps are characterized by piecewise smooth regions bounded by sharp edges along depth discontinuities. Conventional video coding methods tend to introduce ringing artifacts along these depth discontinuities, which lead to visually disturbing geometric distortions in the view synthesis process. Preserving the described signal characteristics of depth maps is therefore a crucial requirement for new depth coding algorithms. In this paper a novel model-based intra-coding mode is presented, which works as an addition to conventional transform-based intra coding tools. The proposed intra coding mode yields up to 42% BD-rate savings in terms of depth rate and up to 2:5% in terms of total rate. The average bitrate savings are approximately 24% for depth rate and 1.5% for the total rate including texture and depth.