An improved similarity-based fast coding unit depth decision algorithm for inter-frame coding in HEVC

The emerging High Efficiency Video Coding (HEVC) aims to achieve significantly improved compression performance with respect to the state-of-the-art H.264/AVC high profile. This better compression performance is achieved at a much higher computational complexity, which makes it difficult for real-time video systems. To reduce the encoding complexity, this paper presents an improved similarity-based fast coding unit depth decision algorithm for inter-frame coding. Firstly, a fast and precise depth information acquisition method is proposed to improve the accuracy of depth prediction. Secondly, CTUs of the medium similarity degree is further divided into two similarity degree categories, and the complexity of coding the coding tree units of these two categories is reduced by different coding unit depth decision strategies. Experimental results show that proposed algorithm can save on average 35.72% of the encoding time with negligible loss on the rate-distortion performance compared with HM11.0 and consistently outperforms the state-of-the-art schemes.