In order to further improve the performance of VC lossless intra coding,this paper improves on the BDPCM coding tool by utilizing the relationships between samples and proposes a sample-based gradient prediction(SGP)algo-rithm.In this algorithm,the prediction samples are obtained from adjacent reference samples in the corresponding predic-tion direction and the gradient information between the reference samples,and the obtained prediction samples are limited to a certain range.The experimental results on the VVC test model(VTM)12.3 reveal that the proposed SGP algorithm can save 5.30％bit-rate on average in VVC lossless intra coding.The encoding time is increased by 17.7％,and the decoding time is decreased by 19.5％.Compared to BDPCM,which achieves 3.88％average bit-rate savings,the bit-rate savings brought by SGP are significantly improved,and the encoding time and the decoding time are both shorter.
关键词
图像编码/无损压缩/帧内预测/梯度预测/通用视频编码(VVC)
Key words
image coding/lossless compression/intra prediction/gradient prediction/versatile video coding(WC)
维普
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