Fast intra-prediction mode decision algorithm in HEVC for depth map coding

As the next generation standard of video coding, the High Efficiency Video Coding (HEVC) provides significantly better coding efficiency than other existing video coding standards. To improve the coding efficiency of intra frame coding, up to 35 intra prediction modes are defined in HEVC. Therefore, HEVC is widely used in stereo video compression scheme more frequently. Stereo video system requires the transmission of depth maps alongside conventional 2D video. However, the computational complexity of encoder increases much due to the additional depth map. In this paper, we present a fast intra mode decision algorithm for depth map coding in HEVC to reduce the computational complexity. Combined with the gradient character of pixels in each prediction unit (PU), only a small part of the candidate modes are chosen for the RDO processes. As compared to the default encoding scheme in HEVC, experimental results show that proposed algorithm provides 25%∼30% time savings with negligible loss of coding efficiency.