Intra prediction method

Abstract

The invention discloses an intra prediction method, which comprises the following steps of: (1) defining N templates in different directions corresponding to N novel intra prediction modes, wherein N is an arbitrary value between 1 and 9, and searching m image blocks which are most similar to the current image blocks to be predicted in a coded image region in a template matching mode; (2) rearranging the most similar m image blocks which are searched in each template to construct a low-rank observation matrix; (3) performing low-rank matrix filling on observation matrixes obtained in N different prediction modes, and reconstructing unknown element values in the observation matrixes to obtain predicted values of the N current image blocks; (4) performing intra prediction on the current image blocks to be predicted by a standard intra prediction method in H.264; and (5) selecting an optimized predicted value from the predicted values obtained in the steps (3) and (4) through rate-distortion optimization, namely selecting an optimized predicted value from (N+1) predicted values. By the method, spatial correlation in an image can be more effectively utilized.

Description

Technical field [0001] The invention belongs to the field of video coding and relates to an intra-frame prediction method. Background technique [0002] As the latest generation of video coding international standards, H.264 / AVC introduces effective methods such as multi-directional intra prediction. Multi-directional intra prediction plays an important role in reducing the spatial redundancy in intra-coded frames in an image or video sequence. H.264 / AVC uses 9 intra prediction modes for 4×4 luma blocks and 8×8 luma blocks, and uses 4 intra prediction modes for 16×16 luma blocks and 8×8 chroma blocks. Each prediction mode corresponds to a specific direction, and the predicted image blocks are predicted based on their encoded neighboring image blocks. There are 8 directional prediction modes among the 9 intra prediction modes for 4×4 image blocks, such as figure 1 Shown. figure 1 The prediction mode 2 not shown in is the DC prediction mode without direction. The prediction valu...

AI Technical Summary

Problems solved by technology

[0011] The innovative idea of ​​the present invention is: use low-rank matrix filling to complete intra-frame prediction, that is, to solve the problem of predicting unknown pixel values ​​in intra-frame prediction as low-rank matrix filling and reconstructing unknown matrix elements

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