Research On Fast Intra Prediction Algorithm For HEVC

HEVC is the next-generation video coding standard after H.264/AVC, which isdeveloped by the Joint Collaborative Team on Video Coding (JCT-VC) established bythe VCEG of ITU-T together with the MPEG of ISO/IEC. It aims to achieve enhancedvideo compression efficiency and provide better flexibility for a wide variety ofnetwork environments, also be able to support multi-core parallel encoding anddecoding. However, the higher performance of HEVC video coding is at the expenseof the higher computational complexity. Because of its high computational complexity,it is hard for practical applications. Therefore, it is a significant research topic toreduce the algorithm complexity and speed up the encoding for facilitating itspractical applications in HEVC video coding.In order to reduce the algorithm complexity of HEVC video coding, this paperfirstly studies the HEVC video coding and its key technology, then an in-depth studyon intra prediction algorithm of HEVC video coding is performed. Based on theanalysis of the algorithm complexity, this paper proposes two fast HEVC intraprediction algorithms. First, based on the in-depth study and large number ofexperiments, the correlation between the texture complexity of picture, predictionresiduals and the block type selection is analyzed, then a fast HEVC intra predictionblock partitioning algorithm based on picture feature and prediction residuals isproposed. The experimental results show that the algorithm saves averagely about40.18%of the encoding time with ignorable degradation of coding performance,which speeds up the encoding efficiently. Second, a fast HEVC intra prediction modedecision algorithm is proposed to reduce the complexity of HEVC intra predictionmode decision algorithm. The algorithm firstly uses the spatial domain and transformdomain feature to screening the prediction modes, and makes optimization for theMPM, lastly performs the mode decision based on RDO. The experimental resultsshow that the algorithm saves averagely about28.45%of the encoding time with negligible loss of the video quality and a little decrease of the bitrate. At last, thispaper combines the two proposed fast HEVC intra prediction algorithm, and theexperimental results show that the combined algorithm saves averagely about52.35%of the encoding time with ignorable degradation of coding performance, greatlyspeeds up the encoding, and enhances the coding efficiency, which is of positivesignificance for the practical applications of HEVC.