A fast HEVC intra-coding algorithm based on texture homogeneity and spatio-temporal correlation

• Published in: EURASIP journal on advances in signal processing Vol. 2018; no. 1; pp. 1 - 14
• Main Authors: Lu, Xin, Yu, Chang, Jin, Xuesong
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 18.06.2018; Springer; Springer Nature B.V; SpringerOpen
• Subjects: Algorithms; Coding; Complexity; Credit unions; CU size decision; Efficiency; Engineering; Fast implementation; HEVC; Homogeneity; Image coding; Partitioning; Prediction mode decision; Quantum Information Technology; Signal,Image and Speech Processing; Spintronics; Video compression; China; Fast implementation; HEVC; CU size decision; Prediction mode decision
• ISSN: 1687-6180; 1687-6172; 1687-6180
• DOI: 10.1186/s13634-018-0558-4

The high efficiency video coding (HEVC) standard supports a flexible coding tree unit (CTU) partitioning structure, and thus coding efficiency is improved significantly. However, the use of this technique inevitably results in greatly increased encoding complexity. In order to reduce the complexity of intra-coding, we propose a hybrid scheme consisting of fast coding unit (CU) size decision and fast prediction unit (PU) mode decision processes. An adaptive method is utilised to measure the homogeneity of video content thus avoiding unnecessary rate distortion (RD) evaluations. The depth range to be tested is narrowed based on the partitioning parameters of the spatially adjacent CUs and the temporally co-located CU. Furthermore, the mode correlation between neighbouring frames and between adjacent coding levels in the same quad-tree structure is taken into account to predict the most probable directional mode. The number of candidate PU modes is further decreased according to the Hadamard cost. Experimental results illustrate that our scheme achieves a significant reduction in computational complexity of HEVC intra-coding. Compared with the HM encoder, the encoding time is reduced by up to 71% with negligible degradation in coding efficiency.