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Motion-Compensated video coding with Adaptive Perceptual Quantization

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 1991年第4期1卷 351-361页

作者： Puri, Atul Aravind, R. AT&T Bell Labs Holmdel NJ 07733 USA

The Motion Picture Experts Group (MPEG) has standardized a syntax for the coded representation of video. The standard specifies only the bit-stream syntax and thereby a method of decoding. It allows much flexibility in designing the encoder for optimal trade-off of complexity versus performance. The syntax supports the basic encoder operations of motion compensation, quantization of discrete cosine transform (DCT) coefficients and variable-length coding. The operation key to reconstructed picture quality is that of quantizing the DCT coefficients. Adaptive quantization techniques conforming to the MPEG syntax can significantly improve the performance of the encoder. In this paper, we develop a strategy for adaptive quantization that uses a perceptual basis for optimizing picture quality. We concentrate on a one-pass causal scheme to limit the complexity of the encoder. The system employs prestored models for perceptual quality and bit rate that have been experimentally derived. A framework Is provided for determining these models as well as adopting them to locally varying scene characteristics.

关键词： video coding Quantization Discrete cosine transforms video compression Transform coding Motion pictures Bit rate Standards organizations HDTV Decoding

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On the encoding of the anchor frame in video coding

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 1997年第3期43卷 279-285页

作者： Kondi, LP Katsaggelos, AK Department of Electrical and Computer Engineering Northwestern University Evanston IL USA

In this paper we determine the number of bits to be used for the encoding of the anchor frame in low bit rate video coding in order to improve the quality of the next and subsequent frames to be encoded. This problem is important in a rear time video communication system. We use a progressive method for the transmission of the anchor frame. We develop two methods for determining the optimal number of bits to be allocated to the first frame in on line video communication applications.

关键词： Encoding video coding Bit rate Image reconstruction Image sequences Delay effects Image coding Asynchronous transfer mode Real time systems Quantization

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End-to-End Rate-Distortion Optimized Description Generation for H.264 Multiple Description video coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 2013年第9期23卷 1523-1536页

作者： Xu, Yuanyuan Zhu, Ce Univ Elect Sci & Technol China Sch Elect Engn Chengdu 610054 Peoples R China

In this paper, H.264/AVC primary and redundant slices interlaced multiple description video coding (PRSI-MDVC) is studied due to its high coding efficiency and ease of constructing multiple descriptions by interleaving primary and redundant slices, where the problem of optimal description generation in the rate-distortion sense is addressed. Optimal description generation requires minimization of end-to-end distortion consisting of both source coding distortion determined by quality of primary slices and channel distortion associated with redundant slice coding, subject to a rate constraint. The relevant existing works on the description generation mainly focus on the estimation of channel distortion to determine the amount of inserted redundancy (quality of redundant slices) but ignore the source distortion estimation for the quality of primary slices, thus a comprehensive end-to-end rate-distortion optimization is still unavailable. In this paper, we attack the minimization of the end-to-end distortion by fully exploring temporal coding dependency. Specifically, on one hand, a most recently developed source distortion temporal propagation model is employed to determine coding options of primary slices in the PRSI-MDVC. On the other hand, channel distortion estimation is mainly concerned with the mismatch error estimation when primary slices are lost. Unlike the existing channel distortion estimation approach under the asymptotic fine quantization assumption which is not valid in most practical cases (e.g., at low or medium coding rates), we develop a novel and more feasible estimation scheme, based on which coding parameters of the redundant slices can be better determined. Simulation results show the effectiveness of the proposed frame-level rate-distortion optimized description generation scheme compared with the relevant approaches.

关键词： Channel distortion multiple description coding (MDC) rate-distortion optimization (RDO) source distortion video coding

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Rate-distortion and complexity optimized motion estimation for H.264 video coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 2008年第2期18卷 159-171页

作者： Ates, Hasan F. Altunbasak, Yucel Isik Univ Dept Elect Engn TR-34980 Istanbul Turkey Georgia Inst Technol Sch Elect & Comp Engn Atlanta GA 30332 USA

11.264 video coding standard supports several inter-prediction coding modes that use macroblock (MB) partitions with variable block sizes. Rate-distortion (R-D) optimal selection of both the motion vectors (MVs) and the coding mode of each MB is essential for an H.264 encoder to achieve superior coding efficiency. Unfortunately, searching for optimal MVs of each possible subblock incurs a heavy computational cost. In this paper, in order to reduce the computational burden of integer-pel motion estimation (ME) without sacrificing from the coding performance, we propose a R-D and complexity joint optimization framework. Within this framework, we develop a simple method that determines for each MB which partitions are likely to be optimal. MV search is carried out for only the selected partitions, thus reducing the complexity of the ME step. The mode selection criteria is based on a measure of spatiotemporal activity within the MB. The procedure minimizes the coding loss at a given level of computational complexity either for the full video sequence or for each single frame. For the latter case, the algorithm provides a tight upper bound on the worst case complexity/execution time of the ME module. Simulation results show that the algorithm speeds up integer-pel ME by a factor of up to 40 with less than 0.2 dB loss in coding efficiency.

关键词： complexity H.264 motion estimation (ME) optimization rate-distortion (R-D) video coding

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Free-Energy Principle Inspired video Quality Metric and Its Use in video coding

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IEEE TRANSACTIONS ON MULTIMEDIA 2016年第4期18卷 590-602页

作者： Xu, Long Lin, Weisi Ma, Lin Zhang, Yongbing Fang, Yuming Ngan, King Ngi Li, Songnan Yan, Yihua Chinese Acad Sci Key Lab Solar Act Natl Astron Observ Beijing 100012 Peoples R China Nanjing Univ Informat Sci & Technol Sch Comp & Software Jiangsu Engn Ctr Network Monitoring Nanjing 210044 Jiangsu Peoples R China Nanyang Technol Univ Dept Comp Engn Singapore 639798 Singapore Huawei Noahs Ark Lab Hong Kong 999077 Hong Kong Peoples R China Tsinghua Univ Grad Sch Shenzhen Shenzhen 518005 Peoples R China Jiangxi Univ Finance & Econ Sch Informat Technol Nanchang 330032 Peoples R China Chinese Univ Hong Kong Dept Elect Engn Hong Kong 999077 Hong Kong Peoples R China

In this paper, we extend the free-energy principle to video quality assessment (VQA) by incorporating with the recent psychophysical study on human visual speed perception (HVSP). A novel video quality metric, namely the free-energy principle inspired video quality metric (FePVQ), is therefore developed and applied to perceptual video coding optimization. The free-energy principle suggests that the human visual system (HVS) can actively predict "orderly" information and avoid "disorderly" information for image perception. Basically, "orderly" is associated with the skeletons and edges of objects, and "disorderly" mostly concerns textures in images. Based on this principle, an image is separated into orderly and disorderly regions, and processed differently in image quality assessment. For videos, visual attention, or fixation, is associated with the objects with significant motion according to HVSP, resulting in a motion strength factor in the FePVQ so that the free-energy principle is extended into spatio-temporal domain for VQA. In addition, we investigate the application of the FePVQ in perceptual rate distortion optimization (RDO). For this purpose, the FePVQ is realized with low computational cost by using the relative total variation model and the block-wise motion vectors of video coding to simulate the free-energy principle and the HVSP, respectively. The experimental results indicate that the proposed FePVQ is highly consistent with the HVS perception. The linear correlation coefficient and Spearman's rank-order correlation coefficient are up to 0.8324 and 0.8281 on the LIVE video database. Better perceptual quality of encoded video sequences is achieved by FePVQ-motivated RDO in video coding.

关键词： Free-energy principle perceptual video coding optimization video coding visual quality assessment (VQA)

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Trends and perspectives in image and video coding

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PROCEEDINGS OF THE IEEE 2005年第1期93卷 6-17页

作者： Sikora, T Tech Univ Berlin D-10587 Berlin Germany

The objective of the paper is to provide an overview on recent trends and future perspectives in image and video coding. Here, I review and the rapid development in the field during the past 40 years and outline current state-of-the art strategies for coding images and videos. These and other coding algorithms are discussed in the context of international JPEG, JPEG 2000, MPEG-1/2/4, and H.261/3/4 standards. Novel techniques targeted at achieving higher compression gains, error robustness, and network/device adapt-ability are described and discussed.

关键词： discrete cosine transform (DCT) distributed source coding embedded coding error concealment image coding International Telecommunication Union-Telecommunications (ITU-T) Joint Photographic Experts Group (JPEG) motion compensation JPEG 2000 Motion Picture Experts Group (MPEG) standardization video coding wavelets

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A Switchable Deep Learning Approach for In-Loop Filtering in video coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 2020年第7期30卷 1871-1887页

作者： Ding, Dandan Kong, Lingyi Chen, Guangyao Liu, Zoe Fang, Yong Hangzhou Normal Univ Sch Informat Sci & Engn Hangzhou 311121 Peoples R China Visionular Inc Mountain View CA 94040 USA Changan Univ Sch Informat Engn Xian 710064 Peoples R China

Deep learning provides a great potential for in-loop filtering to improve both coding efficiency and subjective quality in video coding. State-of-the-art work focuses on network structure design and employs a single powerful network to solve all problems. In contrast, this paper proposes a deep learning based systematic approach that includes an effective Convolutional Neural Network (CNN) structure, a hierarchical training strategy, and a video codec oriented switchable mechanism. First, we propose a novel CNN structure, i.e., Squeeze-and-Excitation Filtering CNN (SEFCNN), as an optional in-loop filter. To capture the non-linear interaction between channels, the SEFCNN is comprised of two subnets, i.e., Feature EXtracting (FEX) subnet and Feature ENhancing (FEN) subnet. Then, we develop a hierarchical model training strategy to adapt the two subnets to different coding scenarios. For high-rate videos with small artifacts, we train a single global model using the FEX for all types of frames, whereas for low-rate videos with large artifacts, different models are trained using both FEX and FEN for different types of frames. Finally, we propose an adaptive enhancing mechanism which is switchable between the CNN-based and the conventional methods. We selectively apply the CNN model to some frames or some regions in a frame. Experimental results show that the proposed scheme outperforms state-of-the-art work in coding efficiency, while the computational complexity is acceptable after GPU acceleration.

关键词： Encoding video coding Feature extraction Adaptation models Tools Training Correlation CNN in-loop filter video coding enhancement

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Sparse Representation With Spatio-Temporal Online Dictionary Learning for Promising video coding

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2016年第10期25卷 4580-4595页

作者： Dai, Wenrui Shen, Yangmei Tang, Xin Zou, Junni Xiong, Hongkai Chen, Chang Wen Univ Calif San Diego Dept Biomed Informat La Jolla CA 92093 USA Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China Shanghai Univ Key Lab Special Fiber Opt & Opt Access Network Shanghai 200072 Peoples R China SUNY Buffalo Dept Comp Sci & Engn Buffalo NY 14260 USA

Classical dictionary learning methods for video coding suffer from high computational complexity and interfered coding efficiency by disregarding its underlying distribution. This paper proposes a spatio-temporal online dictionary learning (STOL) algorithm to speed up the convergence rate of dictionary learning with a guarantee of approximation error. The proposed algorithm incorporates stochastic gradient descents to form a dictionary of pairs of 3D low-frequency and high-frequency spatio-temporal volumes. In each iteration of the learning process, it randomly selects one sample volume and updates the atoms of dictionary by minimizing the expected cost, rather than optimizes empirical cost over the complete training data, such as batch learning methods, e.g., K-SVD. Since the selected volumes are supposed to be independent identically distributed samples from the underlying distribution, decomposition coefficients attained from the trained dictionary are desirable for sparse representation. Theoretically, it is proved that the proposed STOL could achieve better approximation for sparse representation than K-SVD and maintain both structured sparsity and hierarchical sparsity. It is shown to outperform batch gradient descent methods (K-SVD) in the sense of convergence speed and computational complexity, and its upper bound for prediction error is asymptotically equal to the training error. With lower computational complexity, extensive experiments validate that the STOL-based coding scheme achieves performance improvements than H.264/AVC or High Efficiency video coding as well as existing super-resolution-based methods in rate-distortion performance and visual quality.

关键词： Online dictionary learning sparse representation video coding stochastic gradient descent K-SVD

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Content Adaptive Hierarchical Decision of Variable coding Block Sizes in High Efficiency video coding for High Resolution videos

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2013年第4期E96A卷 780-789页

作者： Tian, Guifen Jin, Xin Goto, Satoshi Waseda Univ Grad Sch Informat Prod & Syst Kitakyushu Fukuoka 8080135 Japan Tsinghua Univ Grad Sch Shenzhen Beijing 518055 Peoples R China Waseda Univ IT Res Org Kitakyushu Fukuoka 8080135 Japan

The quadtree-based variable block sized prediction makes the biggest contribution for dramatically improved coding efficiency in the new video coding standard named HEVC. However, this technique takes about 75-80% computational complexity of an HEVC encoder. This paper brings forward an adaptive scheme that exploits temporal, spatial and transform-domain features to speed up the original quadtree-based prediction, targeting at high resolution videos. Before encoding starts, analysis on utilization ratio of each coding depth is performed to skip rarely adopted coding depths at frame level. Then, texture complexity (TC) measurement is applied to filter out none-contributable coding blocks, for each largest coding unit (LCU). In this step, a dynamic threshold setting approach is proposed to make filtering adaptable to videos and coding parameters. Thirdly, during encoding process, sum of absolute quantized residual coefficient (SAQC) is used as criterion to prune useless coding blocks for both LCUs and 32 x 32 blocks. By using proposed scheme, motion estimation is performed for prediction blocks within a narrowed range. Experiments show that proposed scheme outperforms existing works and speeds up original HEVC by a factor of up to 61.89% and by an average of 33.65% for 4kx2k video sequences. Meanwhile, the peak signal-to-noise ratio (PSNR) degradation and bit increment are trivial.

关键词： video coding HEVC content adaptive variable block sized prediction sum of absolute quantized residual coefficient

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MPEG-4 natural video coding - An overview

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2000年第4-5期15卷 365-385页

作者： Ebrahimi, T Horne, C Ecole Polytech Fed Lausanne Swiss Fed Inst Technol Signal Proc Lab CH-1015 Lausanne Switzerland Mediamat Inc Fremont CA 94538 USA

This paper describes the MPEG-4 standard, as defined in ISO/IEC 14496-2. The MPEG-4 visual standard is developed to provide users a new level of interaction with visual contents. It provides technologies to view, access and manipulate objects rather than pixels, with great error robustness at a large range of bit-rates. Application areas range from digital television, streaming video, to mobile multimedia and games. The MPEG-4 natural video standard consists of a collection of tools that support these application areas. The standard provides tools for shape coding, motion estimation and compensation, texture coding, error resilience, sprite coding and scalability. Conformance points in the form of object types, profiles and levels, provide the basis for interoperability. Shape coding can be performed in binary mode, where the shape of each object is described by a binary mask, or in gray scale mode, where the shape is described in a form similar to an alpha channel, allowing transparency, and reducing aliasing. Motion compensation is block based, with appropriate modifications for object boundaries. The block size can be 16 x 16, or 8 x 8, with half pixel resolution. MPEG-4 also provides a mode for overlapped motion compensation. Texture coding is based in 8 x 8 DCT, with appropriate modifications for object boundary blocks. Coefficient prediction is possible to improve coding efficiency. Static textures can be encoded using a wavelet transform. Error resilience is provided by resynchronization markers, data partitioning, header extension codes, and reversible variable length codes. Scalability is provided for both spatial and temporal resolution enhancement. MPEG-4 provides scalability on an object basis, with the restriction that the object shape has to be rectangular. MPEG-4 conformance points are defined at the Simple Profile, the Core Profile, and the Main Profile. Simple Profile and Core Profiles address typical scene sizes of QCIF and CIF size, with bit-rates

关键词： MPEG-4 visual video coding object based coding streaming interactivity

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