Single depth intra coding mode in 3D-HEVC

As the state-of-the-art video coding standard, High Efficiency Video Coding (HEVC) has been finalized in January 2013. To support the coding of multiple views and associated depth data, the development of the HEVC extension for 3D video coding is also about to be finalized. New coding unit (CU) level coding tools are added to the HEVC design to improve the compression capabilities for both video views and depth data. In this paper, we introduce a new coding mode termed as "Single Depth Intra Coding Mode" to efficiently code the smooth area within a depth map. The concept of single depth mode is to simply reconstruct a coding block with a single depth value based on block merging scheme under the HEVC quad-tree based block partitioning. The proposed single depth mode has been adopted into the working draft and 3D-HEVC test model 12 (HTM-12.0). The experimental results evaluated under the common test conditions (CTC) for 3D-HEVC show that the proposed technique achieves up to 5% bit-rate saving for depth coding and on average 0.3% bit-rate saving regarding the synthesis results over the texture and depth bit-rate with decoding time reduced by 4%.