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Introducing skip mode in distributed video coding

SIGNAL PROCESSING-IMAGE COMMUNICATION 2009年第3期24卷 200-213页

作者： Mys, Stefaan Slowack, Jurgen Skorupa, Jozef Lambert, Peter Van de Walle, Rik Univ Ghent IBBT Dept Elect & Informat Syst Multimedia Lab B-9050 Ghent Belgium

Although it was proven in the 1970s already by Wyner and Ziv and Slepian and Wolf that, under certain conditions, the same rate-distortion boundaries exist for distributed video coding (DVC) systems as for traditional predicting systems, until now no practical DVC system has been developed that even comes close to the performance of state-of-the-art video codecs such as H.264/AVC in terms of rate-distortion. Some important factors for this are the lower accuracy of the motion estimation performed at the decoder, the inaccurate modeling of the correlation between the side information and the original frame, and the absence in most state-of-the-art DVC systems of anything conceptually similar to the notion of skipped macroblocks in predictive coding systems. This paper proposes an extension of a state-of-the-art transform domain residual DVC system with an implementation of skip mode. The skip mode has an impact at two different places: in the turbo decoder, more specifically the soft input, soft output (SISO) convolutional decoder, and in the puncturing of the parity bits. Results show average bitrate gains up to 39% (depending on the sequence) achieved by combining both approaches. Furthermore, a hybrid video codec is presented where the motion estimation task is shifted back to the encoder. This results in a drastic increase in encoder complexity, but also in a drastic performance gain in terms of rate-distortion, with average bitrate savings up to 60% relative to the distributed video codec. in the hybrid video codec, smaller but still important average bitrate gains are achieved by implementing skip mode: up to 24%. (C) 2008 Elsevier B.V. All rights reserved.

关键词： Distributed video coding Wyner-Ziv coding Skip mode coding efficiency

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Design of a context-adaptive variable length encoder for real-time video compression on reconfigurable platforms

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IET IMAGE PROCESSING 2012年第4期6卷 301-308页

作者： Licciardo, G. D. Albanese, L. Freda Univ Salerno Dept Elect & Informat Engn DIEII I-84084 Salerno Italy

In this study, a new context-adaptive variable length-coding encoder architecture is proposed particularly aimed to be implemented with field programmable logics (FPL) like FPGAs. The design implements different approaches in order to minimise the area cost as well as to speed up the coding efficiency, which allows real-time compression of 1080 p video streams coded in YCbCr 4:2:0 format. Priority cascading logics have been implemented in order to increase the parallelisation degree of the pre-coding stage, thus favouring the limitation of the number of clock cycles needed for the extraction of symbols from the input data, whereas the employment of the arithmetic table elimination technique has allowed a large-area reduction of the encoder thanks to the elimination of 18 of the 38 tables needed for the encoding stage. The design achieves real time elaboration with an operation frequency of 63 MHz and occupies 2200 look-up table (LUT)s when implemented on a low-cost, low-end XILINX Spartan 3 FPGA, thus overcoming the most recent FPL implementation and making this encoder quite comparable both in terms of area and speed with some recently proposed ASIC implementations, so that it turns out to be a valid alternative also for application specific implementations.

关键词： precoding parallelisation degree field programmable logics look-up table reconfigurable platform data compression table lookup variable length codes field programmable gate arrays FPL implementation Xilinx Spartan 3 real-time video compression coding efficiency priority cascading logics Image and video coding precoding stage arithmetic table elimination technique low-end XILINX Spartan 3 FPGA Logic circuits Computer architecture video coding Logic and switching circuits clocks reconfigurable architectures YCbCr 4:2:0 format context-adaptive variable length-coding encoder architecture Video signal processing video streaming length-coding encoder architecture symbols extraction clock cycle ASIC implementation

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The MPEG-4 video standard verification model

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1997年第1期7卷 19-31页

作者： Sikora, T Laboratory of Chromatography DEPg.Fac.Quimica Universidad Nacional Autonoma de Mexico Circuito interior Cd Universitaria/CP 04510 Mexico D.F.Mexico

The MPEG-4 standardization phase has the mandate to develop algorithms for audio-visual coding allowing for interactivity, high compression, and/or universal accessibility and portability of audio and video content. In addition to the conventional ''frame''-based functionalities of the MPEG-1 and MPEG-2 standards, the MPEG-4 video coding algorithm will also support access and manipulation of ''objects'' within video scenes. The January 1996 MPEG Video group meeting witnessed the definition of the first version of the MPEG-4 Video Verification Model-a milestone in the development of the MPEG-4 standard. The primary intent of the Video Verification Model is to provide a fully defined core video coding algorithm platform for the development of the standard. As such, the structure of the MPEG-4 Video Verification Model already gives some indication about the tools and algorithms that will be provided by the final MPEG-4 standard. The purpose of this paper is to describe the scope of the MPEG-4 Video standard and to outline the structure of the MPEG-4 Video Verification Model under development.

关键词： coding efficiency compression error robustness flexible coding functional coding manipulation MPEG MPEG-4 multimedia natural video object-based coding SNHC standardization synthetic video universal accessibility verification model video coding

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Synthesis-Based Texture Video coding with Side Information

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2011年第5期21卷 647-659页

作者： Oh, Byung Tae Su, Yeping Segall, C. Andrew Kuo, C. -C. Jay Samsung Adv Inst Technol Younggin Si 449712 Gyunggi Do South Korea Sharp Labs Amer Camas WA 98607 USA Univ So Calif Dept Elect Engn Los Angeles CA 90089 USA Univ So Calif Signal & Image Proc Inst Los Angeles CA 90089 USA

The addition of a new component to the traditional synthesis-based texture video coding algorithm is investigated in this paper. That is, we add the side information in the form of low-quality video to enhance the texture video synthesis performance with reducing the unpleasant mismatch between analyzed and synthesized regions. As compared with the conventional synthesis algorithm, our algorithm is more flexible since the behavior and quality of the output texture can be adjusted by the amount of the side information, which is determined by the user. To this end, we develop an area-adaptive side information selection scheme that chooses the proper amount of the side information for a given bit budget. Furthermore, we propose a texture decomposition scheme that extracts the non-synthesizable illumination component from the source video for separate coding so as to maximize the synthesis functionality. The superior performance of the proposed texture video synthesis technique is demonstrated by several coding examples.

关键词： coding efficiency example-based synthesis illumination variant non-parametric synthesis side information synthesis-based coding texture decomposition texture synthesis video compression

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Restricted H.264/AVC video coding for privacy protected video scrambling

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2011年第6期22卷 479-490页

作者： Dai, Feng Tong, Lingling Zhang, Yongdong Li, Jintao Chinese Acad Sci Inst Comp Technol Multimedia Comp Grp Beijing Peoples R China Chinese Acad Sci Grad Univ Beijing Peoples R China

The issue of personal privacy has garnered significant attention with the extensive application of video surveillance systems. Privacy region scrambling is an effective method to protect privacy in video. To ensure that nonprivacy regions are not affected by scrambling, particular methods must be taken to prevent drift error in privacy protected video scrambling. However, existing methods have significantly reduced the coding efficiency. In this paper, we focus on improving coding efficiency while preventing drift error in privacy protected H.264/AVC video scrambling, which is the state-of-the-art coding standard. A restricted video coding scheme is proposed, which involves three parts of Mode Restricted Intra Prediction (MRIP), Search Window Restricted Motion Estimation (SWRME) and Boundary Strength Restricted Deblocking Filtering (BSRDF). Experimental results show that the proposed restricted video coding scheme prevents drift error with higher coding efficiency than others. (C) 2011 Elsevier Inc. All rights reserved.

关键词： coding efficiency Drift error H.264/AVC Privacy protection Restricted video coding Security Video surveillance Video scrambling

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Application of multipled block codes to hunting-free reframing and asynchronous multiplexing

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IEICE TRANSACTIONS ON COMMUNICATIONS 2004年第11期E87B卷 3187-3194页

作者： Yoshida, H Takasaki, Y Toyo Univ Grad Sch Engn Kawagoe 3508585 Japan

\Application of multipled block codes (MBCs) for realizing new flexible and efficient transmission systems that feature in huntingfree reframing and asynchronous multiplexing is investigated. First, the principles of MBC are overviewed to show the capacities of filterless clock recovery. Then it is shown that modification of simple frame structure of MBC line code can be used for attaining hunting-free reframing for multiplexing systems. Two types of MBCs are developed to this end. While the one uses header blocks for hunting-free reframing, the other uses distributed frame patterns. Header design of multipled block codes (MBC) for hunting-free reframing (HFR) is investigated for frame patterns with and without violation compensation. The feasibility of hunting-free reframing is tested in an experimental system. Application of hunting-free reframing to asynchronous multiplexing is also investigated and tested in an experimental system. Finally, advantages of hunting-free multiplexing systems are discussed.

关键词： multipled block codes hunting-free reframing header type frame asynchronous multiplexing coding efficiency

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Double bit range estimation with eight estimators for CABAC in VVC

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IET IMAGE PROCESSING 2022年第12期16卷 3155-3163页

作者： Chan, Ka-Hou Im, Sio-Kei Macao Polytech Univ Fac Appl Sci Taipa Macau Peoples R China Macao Polytech Univ Taipa Macau Peoples R China

This work describes the modification of Context-based Adaptive Binary Arithmetic coding (CABAC) using the double bit range estimation in the VVC engine and the consideration of range updates by using eight hypothetical probability estimators. The focus is on the selected adaptation rates performed in these proposed estimators, which are chosen based on memory consideration and coding efficiency. An investigation of arithmetic coding engines with multi-hypothesis probability estimates and their consideration of contextual modeling of entropy coding at the level of transform coefficients. The proposed scheme enables a quantitative representation of probabilistic predictions linearly and describes the scalability potential for higher accuracy. In addition, this work discusses the hardware implementation, which is based on simple operations such as bitwise operations and subinterval updates. The experimental results validate the effectiveness of the proposed approach specified in VTM framework. The improved results show that it provides more significant gains in terms of RA and LD, which is better than the AI configuration.

关键词： hypothetical probability estimators memory consideration VVC engine probability arithmetic coding engines Context-based Adaptive Binary Arithmetic coding double bit range estimation multihypothesis probability estimates binary codes entropy coding entropy codes range updates selected adaptation rates coding efficiency CABAC adaptive codes arithmetic codes video coding

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Reducing Quantization Noise to Boost efficiency and Signal Bandwidth in Delta-Sigma-Based Transmitters

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 2013年第12期61卷 4245-4251页

作者： Ebrahimi, Mohammad Mojtaba Helaoui, Mohamed Univ Calgary Dept Elect Engn IRadio Lab Calgary AB T2N 1N4 Canada Univ Calgary Dept Elect & Comp Engn Calgary AB T2N 1N4 Canada

This paper introduces two new techniques to enhance both efficiency and signal bandwidth in delta-sigma-based transmitters. At first step, a technique called quantization noise reduction (QNR), is introduced to enhance the coding efficiency. By filtering out part of the quantization noise in the whole band of the signal, while the signal envelope is maintained almost constant, the coding efficiency is improved without imposing any additional nonlinearity or distortion to the system. By utilizing this technique for an orthogonal frequency division multiplexing (OFDM) signal with 1.25-MHz bandwidth and 80 times oversampling, with 8.1-dB peak-to-average power ratio (PAPR), the coding efficiency is improved from 8.8% to 14.5% while the signal-to-noise distortion ratio (SNDR) of the system remains 43 dB. In the next step by using a controlled filtering on in-band quantization noise along with QNR technique, the bandwidth of the signal and efficiency are increased simultaneously without losing as much linearity. The second technique is called quantization noise reduction with in-band filtering or (QNRIF). QNRIF is applied on an OFDM signal with 1.25-MHz bandwidth, with the same PAPR and only 16 times oversampling. The result for the coding efficiency is improved from 7.7% to 18.7% with 41-dB SNDR.

关键词： coding efficiency delta-sigma modulator (DSM) peak-to-average power ratio (PAPR) switching-mode power amplifier (SMPA)

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Optimized Feedback Iterative Online Fountain Code Without Build-Up Phase for Underwater Acoustic Networks

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IEEE SENSORS JOURNAL 2024年第19期24卷 31293-31309页

作者： Zhao, Lei Du, Xiujuan Liu, Xiuxiu Tian, Xiaojing Qinghai Normal Univ Coll Comp Xining 810008 Peoples R China Qinghai Normal Univ Coll Comp Qinghai Prov Key Lab IoT Xining 810008 Peoples R China Qinghai Normal Univ Acad Plateau Sci & Sustainabil Xining 810008 Peoples R China

Online fountain code (OFC) is a new type of fountain codes that can adjust the encoding strategy of the sender based on the decoding state feedbacked by the receiver. With the instant feedback of the decoding state, OFC offers advantages such as optimal encoding and low overhead, which are crucial for achieving low latency and high-reliability communication in underwater acoustic networks (UANs) with characteristics such as high error rate, long delay, and half-duplex communication. In this article, three optimization objectives for OFC in UANs are proposed through analyzing the characteristics of UANs and issues of OFC in UANs. Aiming at the three optimization objectives, an optimized feedback iterative OFC without build-up phase (OFI-OFCNB) is proposed to improve the intermediate decoding performance while reducing the coding and feedback overhead for UANs. Meanwhile, considering that the receivers with low-complexity requirements usually have limited buffer sizes to store partially encoded packets, the OFI-OFCNB dynamically adjusts the buffer occupancy to avoid buffer overflow. In addition, the number of encoded and feedback packets, the overhead, the complexity, and the buffer occupancy of OFI-OFCNB are analyzed. The analysis and simulation results validate the superior performance of OFI-OFCNB in terms of the coding and feedback overhead, the intermediate performance, and the buffer occupancy.

关键词： coding efficiency intermediate performance overhead underwater acoustic networks (UANs) coding efficiency intermediate performance overhead underwater acoustic networks (UANs)

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SKIP prediction for fast rate distortion optimization in H.264

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 2007年第3期53卷 1153-1160页

作者： Saha, Avishek Mallick, Kallol Mukherjee, Jayanta Sural, Shamik Indian Inst Technol Dept Comp Sci & Engn Kharagpur 721302 W Bengal India Indian Inst Technol Sch Info Tech Kharagpur 721302 W Bengal India

In H.264, the optimal coding mode for each macroblock (MB) is selected by exhaustively searching all MB modes in the multiple reference frames. The exhaustive mode search has a very high computational complexity. This paper proposes three different approaches along with their combination to reduce the complexity of the rate-distortion optimized mode decision process in H.264. These approaches are based on tran form-domain properties and spatio-temporal correlation in video sequences. Experimental results demonstrate that the proposed methods achieve around 5-7 times improvement in average speedup with good prediction quality and comparable bitrate.

关键词： SKIP Prediction rho-domain restricted reference frame coding efficiency

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