Fast Intra Coding Algorithm for HEVC Based on Decision Tree

Jia QIN  Huihui BAI  Mengmeng ZHANG  Yao ZHAO  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E100-A   No.5   pp.1274-1278
Publication Date: 2017/05/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E100.A.1274
Type of Manuscript: LETTER
Category: Image
HEVC,  coding unit decision,  intra prediction,  decision tree,  offline training,  

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High Efficiency Video Coding (HEVC) is the latest coding standard. Compared with Advanced Video coding (H.264/AVC), HEVC offers about a 50% bitrate reduction at the same reconstructed video quality. However, this new coding standard leads to enormous computational complexity, which makes it difficult to encode video in real time. Therefore, in this paper, aiming at the high complexity of intra coding in HEVC, a new fast coding unit (CU) splitting algorithm is proposed based on the decision tree. Decision tree, as a method of machine learning, can be designed to determine the size of CUs adaptively. Here, two significant features, Just Noticeable Difference (JND) values and coding bits of each CU can be extracted to train the decision tree, according to their relationships with the CUs' partitions. The experimental results have revealed that the proposed algorithm can save about 34% of time, on average, with only a small increase of BD-rate under the “All_Intra” setting, compared with the HEVC reference software.