Adaptive fast intra mode decision of depth map coding by Low Complexity RD-Cost in 3D-HEVC

The coding efficiency of 3D-HEVC can be improved significantly by adopting more intra modes in depth map coding, including up to 35 conventional HEVC intra prediction modes and 4 depth modelling modes (DMMs). However, traversing these modes dramatically results in unendurable high complexity. In this paper, we propose an efficient intra mode decision algorithm by taking advantage of the Low Complexity Rate-Distortion Cost information in the rough mode decision. Only one conventional intra mode and several most probable modes are then selected for most cases adaptively based on the threshold derived from the prior probability. Experimental results show that the proposed algorithm provides about 34% saving in terms of the total depth coding time with little drop of the coding performance compared with the state-of-the-art algorithm.