Simplified depth map intra coding with an optional depth lookup table

Abstract

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. Therefore, preserving the described signal characteristics of depth maps is a crucial requirement for new depth coding algorithms. In this paper a novel simplified intra-coding mode is presented, which works as an alternative coding path to the conventional transform-based intra coding scheme. The proposed intra coding mode yields up to 1.3% BD-rate savings in terms of total bitrate, including texture bitrate. An optional Depth Lookup Table can further increase the bitrate reduction to 2.1%.