关键词: 3D-HEVC, 帧内预测, 深度图, 深度编码模式, 分段直流编码

Abstract:  This paper proposes a fast depth map intra algorithm based on sum-of-gradient and segment-wise DC coding (SOG-SDC) for reducing the computational complexity of depth map in 3D-HEVC. When processing depth map intra coding, the exhaustive modes searching, the DMMs (depth modeling modes) selection, and the complex decision in segment-wise DC coding (SDC) are time consuming and not always necessary, this paper proposes a sum-of-gradient (SOG) for prediction unit (PU) to prejudge the texture type (flat/non-flat) of coding unit (CU). According to the texture type, the calculation of DMMs can be selectively skipped and the CU splitting process can be earlier terminated. Moreover, for flat texture, the rate distortion list (RD list) can only consists of smooth prediction mode with SDC other than all modes with SDC. The experimental results show that the proposed algorithm can reduce the encoding time by 26.03% compared with HTM16.0, and the bit rate increases by only 0.14%. The subjective quality of the synthesized viewpoint can also show the effectiveness of the proposed algorithm.

Key words: 3D-HEVC, intra prediction, depth map, depth modeling modes, segment-wise DC coding