Quick HEVC (High Efficiency Video Coding) inter-frame prediction mode selection method

Abstract

The invention discloses a quick HEVC (High Efficiency Video Coding) inter-frame prediction mode selection method. After coarse selection of inter-frame prediction modes, the statistical property of Hadamard transform-based cost values corresponding to the coarsely selected inter-frame prediction modes is fully utilized, and the correlation of the video texture direction and an inter-frame prediction mode angle are fully considered; for prediction unit types of different sizes, the inter-frame prediction modes after the coarse selection are quickly screened through a threshold value method or the continuity of the coarsely selected inter-frame prediction modes is calculated to reflect the texture direction of the prediction unit, so that the unnecessary coarsely selected inter-frame prediction mode is screened without introducing more extra calculation; in a verification process of the most possible prediction mode, the correlation of the coarsely selected inter-frame prediction modes and the most possible prediction mode and the space correlation of a video image per se are fully considered, the final optimal inter-frame prediction mode is quickly obtained, and the inter-frame coding complexity is reduced on the premise that the video coding quality is guaranteed.

Description

technical field [0001] The present invention relates to a video coding and decoding technology, in particular to a fast HEVC intra-frame prediction mode selection method. Background technique [0002] With the rapid development of computer technology and the continuous enhancement of terminal processing capabilities, people have higher and higher requirements for digital video information to meet the applications in real-time video monitoring, digital streaming media, ultra-high-definition video and other fields. The International Telecommunication Union (ITU-T) and the Moving Picture Experts Group (MPEG) established the Joint Collaborative Team on Video Coding (JCT-VC) to study a new generation of high-efficiency video coding standards (High Efficiency Video Coding, HEVC), its core goal is to double the compression efficiency on the basis of H.264 / AVC advanced grade, that is, to reduce the encoding bit rate to 50% of the original under the premise of ensuring the same video...

AI Technical Summary

Problems solved by technology

A fast intra-frame prediction mode selection algorithm proposed by Shi Feiyu et al., through hierarchical calculation of 35 intra-frame prediction modes, 17 of them can be used to select the optimal intra-frame prediction mode for the current prediction unit , the experimental results show that compared with the original algorithm, the fast intra-frame prediction mode selection algorithm can reduce the time by more than 50% on average, but the code rate caused by the change is too large, and the code rate rises seriously

A HEVC intra-frame fast mode selection algorithm combined with image texture direction and spatial correlation proposed by Qi Meibin et al., which reduces the number of candidate modes in the RMD (Rough Mode Decision) rough selection process, although the experimental results are good, but D The effects of the class and class C video test sequences are not given, and their general applicability has yet to be demonstrated

A fast intra-frame mode selection algorithm based on the image gradient mode histogram proposed by Jiang et al., which presents the gradient information of each intra-frame mode in the form of a histogram, and then selects the corresponding entry according to the size of the PU unit. The number of candidate modes for the RMD rough selection process and rate-distortion cost value calculation, but for each type of PU unit, the Sobel operator is used to calculate the gradient vector information, which brings additional calculations, but leads to a limited encoding time reduction in the end.

Motrac A Sd et al. used the texture characteristics of the image to have consistency in consecutive video frame images, and proposed to use the coded PU unit at the same position in the adjacent frame and the intra-frame prediction mode of the adjacent coded PU unit in the same frame to reduce The intra prediction mode of the rough selection process has a certain effect, but this method will cause a significant increase in the bit rate

[0005] The above-mentioned algorithms can generally quickly select the intra-frame prediction mode, which reduces the intra-frame encoding time to a certain extent, but many algorithms cause a serious increase in the bit rate, and some algorithms will introduce additional calculations or algorithms. Suitability to be proven

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