arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1609.06302cs.MM
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用于HEVC的基于颜色的编码单元级自适应Quantization

Color-Based Coding Unit Level Adaptive Quantization for HEVC

Lee Prangnell, Victor Sanchez

摘要:

HEVC HM 16包含称为自适应QP的译码单元(CU)层级感知量化技术。AdaptiveQP基于亮度译码块(CB)的四个组成NXN子块中的样本的空间活动性来调整CU层级处的量化参数(QP),亮度译码块(CB)包含于2NX 2N CU内。在本文中,我们提出C-BAQ,其与AdaptiveQP相反,根据亮度和色度CB两者的四个组成NxN子块中的样本的空间活动来调整CU级QP。通过计算CU中的亮度、色度Cb和色度Cr空间活动的总和,获得CU中的空间活动的更丰富反映。因此,可以选择更适当的CU级QP,从而导致编码效率方面的重要改进。我们使用4:4:4、4:2:2和4:2:0 YCbCr序列来评估HEVC HM 16.7中所提出的技术。主观和客观的评价进行期间,我们比较C-BAQ与AdaptiveQP。客观评价表明,C-BAQ达到了最大的BD率减少15.9%(Y),13.1%(Cr)和16.1%(Cb),除了最大的解码时间减少11.0%。

英文摘要:

HEVC HM 16 includes a Coding Unit (CU) level perceptual quantization technique named AdaptiveQP. AdaptiveQP adjusts the Quantization Parameter (QP) at the CU level based on the spatial activity of samples in the four constituent NxN sub-blocks of the luma Coding Block (CB), which is contained within a 2Nx2N CU. In this paper, we propose C-BAQ, which, in contrast to AdaptiveQP, adjusts the CU level QP according to the spatial activity of samples in the four constituent NxN sub-blocks of both the luma and chroma CBs. By computing the sum of luma, chroma Cb and chroma Cr spatial activity in a CU, a richer reflection of spatial activity in the CU is attained. Therefore, a more appropriate CU level QP can be selected, thus leading to important improvements in terms of coding efficiency. We evaluate the proposed technique in HEVC HM 16.7 using 4:4:4, 4:2:2 and 4:2:0 YCbCr sequences. Both subjective and objective evaluations are undertaken during which we compare C-BAQ with AdaptiveQP. The objective evaluation reveals that C-BAQ attains a maximum BD-Rate reduction of 15.9% (Y), 13.1% (Cr) and 16.1% (Cb) in addition to a maximum decoding time reduction of 11.0%.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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