Neural network-based filters have shown their potential in removing video compression artifacts. However, previously studied neural networks have achieved boosted filtering performance by continuously increasing netwo...
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ISBN:
(纸本)9781728103976
Neural network-based filters have shown their potential in removing video compression artifacts. However, previously studied neural networks have achieved boosted filtering performance by continuously increasing network complexity, causing heavy burden on memory cost and computation speed. In this paper, we firstly analyze properties of original residuals which are the difference between original and predicted pixel values. Then an in-loop filter based on low-complexity CNN using residuals(CNNF-R), which are generated after compression and reconstruction from original residuals, is proposed for intra video coding. Insights of designing the network are also demonstrated. Compared with the state-of-the-art videocoding standard HEVC, CNNF-R achieves up to 6.8% BD-rate reduction and 4.8% on average under all intra configuration, and 23% on average under random access configuration. Meanwhile, CNNF-R outperforms the previous network VRCNN in terms of nearly 70% decrease in computation complexity, considerable decrease in memory consumption and 1.2% increase in BD-rate reduction.
In H.264/advanced videocoding (AVC), lossless coding and lossy coding share the same entropy coding module. However, the entropy coders in the H.264/AVC standard were original designed for lossy videocoding and do n...
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In H.264/advanced videocoding (AVC), lossless coding and lossy coding share the same entropy coding module. However, the entropy coders in the H.264/AVC standard were original designed for lossy videocoding and do not yield adequate performance for lossless videocoding. In this paper, we analyze the problem with the current lossless coding scheme and propose a mode-dependent template (MD-template) based method for intra lossless coding. By exploring the statistical redundancy of the prediction residual in the H.264/AVC intra prediction modes, more zero coefficients are generated. By designing a new scan order for each MD-template, the scanned coefficients sequence fits the H.264/AVC entropy coders better. A fast implementation algorithm is also designed. With little computation increase, experimental results confirm that the proposed fast algorithm achieves about 7.2% bit saving compared with the current H.264/AVC fidelity range extensions high profile.
High efficiency videocoding (HEVC) uses a quadtree-based structure for coding unit (CU) splitting to effectively encode various video sequences with different visual characteristics. However, this new structure resul...
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ISBN:
(纸本)9781728180588
High efficiency videocoding (HEVC) uses a quadtree-based structure for coding unit (CU) splitting to effectively encode various video sequences with different visual characteristics. However, this new structure results in a dramatically increased complexity that makes real-time HEVC encoding very challenging. In this paper, we propose a novel CU size decision method based on deep reinforcement learning and active feature acquisition to reduce HEVC intracoding computational complexity and encoding time. The proposed method carries out early splitting and early splitting termination by considering the encoder and CU as an agent-environment system. More specifically, through early splitting, the proposed method precludes the need for rate-distortion optimization at the current level. In addition, through early splitting termination, it disposes of the lower level computations. The proposed method provides a very fast encoder with a small quality penalty. Experimental results show that it achieves a 51.3% encoding time reduction on average with a small quality loss of 0.041 dB for the BD-PSNR, when we compare our method to the HEVC test model.
High efficiency videocoding (HEVC) increases the number of intracoding modes to 35 to provide higher coding efficiency than previous videocoding standards. This results in an increased encoder complexity, since the...
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High efficiency videocoding (HEVC) increases the number of intracoding modes to 35 to provide higher coding efficiency than previous videocoding standards. This results in an increased encoder complexity, since there are more modes to be processed by the high resource-demanding rate-distortion optimization (RDO). In this paper, we propose a novel method to reduce the HEVC intra mode decision computational complexity and encoding time. This method is based on the prediction of the RDO cost of intra modes from a low-complexity sum of absolute transformed differences-based cost. By predicting the RDO cost, we are able to exclude non-promising modes from further processing and thereby save substantial computations. Also, a gradient-based method, using the Prewitt operator, is proposed to eliminate the non-relevant directional modes from the list of candidates. For even more complexity reduction, a mode classification is proposed to adaptively reduce chroma intra modes based on block texture. Experimental results show that we achieve a 47.3% encoding time reduction on average with a negligible quality loss of 0.062 dB for the Bjontegaard delta peak signal-to-noise ratio when we compare our method to the HEVC test model 15.0.
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