Complexity reduction of in-loop filtering for compressed image restoration in HEVC
Complexity reduction of in-loop filtering for compressed image restoration in HEVC
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DOI：
10.1109/pcs.2012.6213376
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发表时间：
2012-05
期刊：
影响因子：
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通讯作者：
K. Miyazawa;T. Murakami;Akira Minezawa;H. Sakate
中科院分区：
文献类型：
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作者：
K. Miyazawa;T. Murakami;Akira Minezawa;H. Sakate
本文提出了一种降低高效视频编码（HEVC）中图像恢复自适应滤波复杂度的方法——自适应环路滤波（ALF）。虽然ALF可以大大提高解码帧的PSNR，但其影响在整个帧中并不均匀，而是取决于局部纹理。基于这一事实，该方法首先通过分数计算来预测ALF对每个像素的有效性，并跳过分数小于阈值的所有ALF处理。该阈值在编码过程中为每一帧自适应地确定，并传输到解码器。实验结果表明，该方法在不影响编码性能的前提下显著减少了ALF的计算时间。
This paper presents a method for reducing the complexity of adaptive filtering for image restoration adopted in High Efficiency Video Coding (HEVC), called Adaptive Loop Filter (ALF). Although ALF can greatly improve the PSNR of decoded frames, its impact is not uniform across an entire frame, but depends on the local texture. Based on this fact, the proposed method first predicts the effectiveness of ALF for each pixel by score calculation, and skips all ALF processes for the pixels whose scores are less than a threshold. This threshold is adaptively determined for each frame in the encoding process, and is transmitted to a decoder. Experimental evaluation clearly demonstrates that the proposed method achieves significant reduction of the computation time of ALF without noticeable encoding performance loss.