  High efficiency video coding (HEVC) suffers high encoding computational
complexity, partly attributed to the rate-distortion optimization quad-tree
search in CU partition decision. Therefore, we propose a novel two-stage CU
partition decision approach in HEVC intra-mode. In the proposed approach,
CNN-based algorithm is designed to decide CU partition mode precisely in three
depths. In order to alleviate computational complexity further, an auxiliary
earl-termination mechanism is also proposed to filter obvious homogeneous CUs
out of the subsequent CNN-based algorithm. Experimental results show that the
proposed approach achieves about 37% encoding time saving on average and
insignificant BD-Bitrate rise compared with the original HEVC encoder.
