Early determination of intra mode and segment-wise DC coding for depth map based on hierarchical coding structure in 3D-HEVC

This paper proposes a fast algorithm to reduce the high computational complexity of depth map coding in 3D-HEVC, which obstructs 3D video from the practical applications. Due to the special feature of depth maps, depth modelling modes (DMMs) were developed to keep sharp edges for depth map. Consequently, the 3D-HEVC encoder can improve the coding performance of synthesized views significantly. However, this is at the significant cost of increased complexity. Since 3D-HEVC reuses the well-known hierarchical coding structure, the mode information of the parent coding units (CU) can be reused to predict the most probable modes for their CUs. Besides, a method is also proposed for early determination of segment-wise DC coding (SDC) decision based on the hierarchical coding structure. Simulation results show that the proposed algorithm achieves a reduction of 33% encoding time while maintaining the quality of synthesized views in term of bit-rate values.