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Rate-distortion optimized mode selection for very low bit rate video coding and the emerging H.263 standard

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1996年第2期6卷 182-190页

作者： Wiegand, T Lightstone, M Mukherjee, D Campbell, TG Mitra, SK CHROMAT RES INC MT VIEW CA 94043 USA UNIV CALIF SANTA BARBARA DEPT ELECT & COMP ENGN SANTA BARBARA CA 93106 USA COMPRESS LABS INC SAN JOSE CA 95134 USA

This paper addresses the problem of encoder optimization in a macroblock-based multimode video compression system, An efficient solution is proposed in which, for a given image region, the optimum combination of macroblock modes and the associated mode parameters are jointly selected so as to minimize the over;dl distortion for a given bit-rate budget, Conditions for optimizing the encoder operation are derived within a rate-constrained product code framework using a Lagrangian formulation, The instantaneous rate of the encoder is controlled by a single Lagrange multiplier that makes the method amenable to mobile wireless networks with time-varying capacity, When rate and distortion dependencies are introduced between adjacent blocks (as is the case when the motion vectors are differentially encoded and/or overlapped block motion compensation is employed), the ensuing encoder complexity is surmounted using dynamic programming. Due to the generic nature of the algorithm, it can be successfully applied to the problem of encoder control in numerous video coding standards, including H.261, MPEG-1, and MPEG-2, Moreover, the strategy is especially relevant for very low bit rate coding over wireless communication channels where the low dimensionality of the images associated with these bit rates makes real-time implementation very feasible, Accordingly, in this paper, the method is successfully applied to the emerging H.263 video coding standard with excellent results at rates as low as 8.0 Kb per second. Direct comparisons with the H.263 test model, TMN5, demonstrate that gains in peak signal-to-noise ratios (PSNR) are achievable over a wide range of rates.

关键词： block codes data compression dynamic programming image segmentation optimisation rate distortion theory telecommunication channels telecommunication standards video coding H.263 standard Lagrangian formulation MPEG-1 MPEG-2 encoder co dynamic programming Block codes very low bit-rate coding encoding complexity image segmentation ENCODER Rate distortion Rate distortion theory Data compression motion vector Video coding

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Network Coding: A Computational Perspective

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IEEE TRANSACTIONS ON INFORMATION THEORY 2009年第1期55卷 147-157页

作者： Langberg, Michael Sprintson, Alexander Bruck, Jehoshua Open Univ Div Comp Sci IL-43107 Raanana Israel Texas A&M Univ Dept Elect & Comp Engn College Stn TX 77845 USA CALTECH Dept Elect Engn Pasadena CA 91125 USA

In this work, we study the computational perspective of network coding, focusing on two issues. First, we address the computational complexity of finding a network code for acyclic multicast networks. Second, we address the issue of reducing the amount of computation performed by network nodes. In particular, we consider the problem of finding a network code with the minimum possible number of encoding nodes, i.e., nodes that generate new packets by performing algebraic operations on packets received over incoming links. We present a deterministic algorithm that finds a feasible network code for a multicast network over an underlying graph G(V, E) in time O(|E|kh + |V|k(2)h(2) + h(4)k(3)(k + h)), where k is the number of destinations and h is the number of packets. Our algorithm improves the best known running time for network code construction. In addition, our algorithm guarantees that the number of encoding nodes in the obtained network code is upper-bounded by O(h(3)k(2)). Next, we address the problem of finding integral and fractional network codes with the minimum number of encoding nodes. We prove that in the majority of settings this problem is NP-hard. However, we show that if h = O(1), k = O(1), and the underlying communication graph is acyclic, then there exists an algorithm that solves this problem in polynomial time.

关键词： Algorithms computational perspective encoding complexity fractional network coding integer network coding multicast connections

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Unequal error protection codes derived from SEC-DED codes

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ELECTRONICS LETTERS 2016年第8期52卷 619-U92页

作者： Reviriego, Pedro Liu, Shan Shan Sanchez-Macian, Alfonso Xiao, Liyi Antonio Maestro, Juan Univ Antonio De Nebrija Escuela Politecn Super C Pirineos 55 Madrid Spain Harbin Inst Technol Ctr Microelect Harbin 15001 Peoples R China

Error correction codes are commonly used to protect the data stored in memories from errors. Among the codes used, single error correction double error detection (SEC-DED) codes are probably the most common due to their simplicity. In some applications, the importance of the bits is different, being some of them critical while others can tolerate some errors. This is the case, for example, in some multimedia and signal processing systems. For those applications, unequal error protection (UEP) codes that provide different protection for different bits can be used. In many cases, the bits that require extra protection are only a few. Therefore, it would be convenient to use a traditional code extended to provide additional protection for a few bits. A simple method to derive UEP codes from SEC-DED codes is presented. The proposed UEP codes protect a few bits against double errors and behave as SEC-DED codes for the rest. encoding and decoding complexity is only slightly larger than that of an SEC-DED code and the implementation is a simple modification of the SEC-DED implementation.

关键词： error correction codes error detection codes unequal error protection codes SEC-DED codes error correction codes single error correction double error detection codes UEP codes decoding complexity encoding complexity signal processing systems multimedia system

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Fast Coding Unit Size Decision Based on Probabilistic Graphical Model in High Efficiency Video Coding Inter Prediction

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IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS 2016年第11期E99D卷 2836-2839页

作者： Jiang, Xiantao Song, Tian Shi, Wen Katayama, Takafumi Shimamoto, Takashi Wang, Lisheng Tongji Univ Dept Elect & Informat Engn Shanghai Peoples R China Univ Tokushima Dept Elect & Elect Engn Tokushima 7708506 Japan

In this work, a high efficiency coding unit (CU) size decision algorithm is proposed for high efficiency video coding (HEVC) inter coding. The CU splitting or non-splitting is modeled as a binary classification problem based on probability graphical model (PGM). This method incorporates two sub-methods: CU size termination decision and CU size skip decision. This method focuses on the trade-off between encoding efficiency and encoding complexity, and it has a good performance. Particularly in the high resolution application, simulation results demonstrate that the proposed algorithm can reduce encoding time by 53.62%-57.54%, while the increased BD-rate are only 1.27%-1.65%, compared to the HEVC software model.

关键词： HEVC CU size encoding complexity probability graphical model

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EFM coding: Squeezing the last bits

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 1997年第3期43卷 491-495页

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

Runlength-limited (RLL) codes have found widespread usage in optical and magnetic recording products. Specifically, the RLL codes EFM and its successor, EFMPlus, are used in the Compact Disc (CD) and the Digital Versatile Disc (DVD), respectively. EFMPlus offers a 6% increase in storage capacity with respect to EFM. The work reports on the feasibility and limits of EFM-like codes that offer an even larger capacity. To this end, we will provide an overview of the various limiting factors, such as runlength constraint, dc-content, and code complexity, and outline their relative effect on the code rate. In the second part of the article we will show how the performance predicted by the tenets of information theory can be realized in practice. A worked example of a code whose rate is 7.5% larger than EFMPlus, namely a rate 256/476, (d = 2, k = 15) code, showing a 13 dB attenuation at f(b) = 10(-3), will be given to illustrate the theory.

关键词： limiting factors Storage capacity Digital versatile discs Information Theory code rate runlength-limited codes Codes coding encoding complexity

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Modified VQ-BTC algorithm for image compression

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ELECTRONICS LETTERS 1998年第14期34卷 1390-1392页

作者： Wang, CC Chen, CH Chen, IH Natl Cheng Kung Univ Dept Elect Engn Tainan 70101 Taiwan

VQ-BTC is a recent technique used in the coding of image data to combat edge degradation produced by vector quantisation (VQ) or block truncation coding (BTC). However, it has high encoding complexity and needs a large amount of memory to store 31 codebooks at both the encoder and decoder. A modified VQ-BTC (MVQ-BTC) algorithm is presented which achieves a performance close to that of VQ-BTC, but needs only three codebooks, and requires less computation time than VQ-BTC.

关键词： large memory computational time encoding complexity image data ENCODER Data compression Vector quantization Block truncation coding Image compression

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Efficient intra-mode decision algorithm skipping unnecessary depth-modelling modes in 3D-HEVC

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ELECTRONICS LETTERS 2015年第10期51卷 756-757页

作者： Park, Chun-Su Sejong Univ Seoul South Korea

The three-dimensional (3D) extension of the high-efficiency video coding (3D-HEVC) standard adopts new depth-modelling modes (DMMs) to provide an alternative prediction scheme for depth-map intra-coding. In 3D-HEVC, although edges in depth maps can be accurately estimated by utilising the DMMs, testing the DMMs in the mode decision introduces a huge computational load to the encoder. A fast mode decision algorithm is proposed that can significantly reduce the computational overhead incurred by the DMMs. Experimental results indicate that the proposed algorithm reduces the encoding complexity by 33.89% on average without any penalty in coding efficiency.

关键词： video coding 3D extension 3D-HEVC DMM coding efficiency computational overhead reduction depth-map intra-coding depth-modelling modes efficient intramode decision algorithm encoding complexity fast-mode decision algorithm high-efficiency video coding standard prediction scheme three-dimensional extension

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A sub-pixel motion estimation skipping method for fast HEVC encoding

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ICT EXPRESS 2019年第2期5卷 136-140页

作者： Park, Sang-hyo Yonsei Univ Barun ICT Res Ctr Seoul 03722 South Korea

While motion estimation (ME) efficiently compresses video data by reducing temporal redundancy between frames, it does so at the cost of computational complexity. In particular, the complexity of sub-pixel ME (SME) greatly limits fast video encoding because the SME requires a complexity-intensive interpolation process to generate imaginary pixels. Thus, this paper proposes a method that conditionally skips SME, including its interpolation process, by utilizing previously encoded motion information. Results show that the proposed method efficiently reduces both the total encoding time and memory access compared to the previous high efficiency video coding (HEVC) reference model. (C) 2018 The Korean Institute of Communications and Information Sciences (KICS). Publishing Services by Elsevier B.V.

关键词： Video compression Fast motion estimation HEVC Interpolation filter encoding complexity

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On LP Decoding of Polar Codes

On LP Decoding of Polar Codes

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IEEE Information Theory Workshop (ITW)

作者： Goela, Naveen Korada, Satish Babu Gastpar, Michael Univ Calif Berkeley Dept EECS Wireless Fdn Ctr Berkeley CA 94720 USA Stanford Univ Dept Elect Engn Stanford CA USA Delft Univ Technol Delft Netherlands

ISBN: (纸本)9781424482641

Polar codes are the first codes to provably achieve capacity on the symmetric binary-input discrete memoryless channel (B-DMC) with low encoding and decoding complexity. The parity check matrix of polar codes is high-density and we show that linear program (LP) decoding fails on the fundamental polytope of the parity check matrix. The recursive structure of the code permits a sparse factor graph representation. We define a new polytope based on the fundamental polytope of the sparse graph representation. This new polytope P is defined in a space of dimension O(N logN) where N is the block length. We prove that the projection of P in the original space is tighter than the fundamental polytope based on the parity check matrix. The LP decoder over P obtains the ML-certificate property. In the case of the binary erasure channel (BEC), the new LP decoder is equivalent to the belief propagation (BP) decoder operating on the sparse factor graph representation, and hence achieves capacity. Simulation results of SC (successive cancelation) decoding, LP decoding over tightened polytopes, and (ML) maximum likelihood decoding are provided. For channels other than the BEC, we discuss why LP decoding over P with a linear objective function is insufficient.

关键词： belief propagation decoder binary codes binary erasure channel computational complexity decoding complexity encoding complexity graph theory linear program decoding linear programming maximum likelihood decoding maximum likelihood decoding parity check codes parity check matrix polar codes sparse factor graph representation successive cancellation decoding symmetric binary-input discrete memoryless channel

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Priority Classification Based Fast Intra Mode Decision for High Efficiency Video Coding

Priority Classification Based Fast Intra Mode Decision for H...

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Picture Coding Symposium (PCS)

作者： Zhang, Hao Liu, Qiang Ma, Zhan Cent S Univ Sch Informat Sci & Engn Changsha 410083 Hunan Peoples R China Samsung Elect Samsung Res Amer Richardson TX 75082 USA

ISBN: (纸本)9781479902941

The latest High-Efficiency Video Coding (HEVC) video coding standard version 1 offers 50% bit rate reduction against the H.264/AVC at the same visual quality. However, HEVC encoder complexity is tremendously increased. It is therefore important to develop efficient encoding algorithms for the success of HEVC based applications. In this paper, we propose a priority classification based fast intra mode decision to speed up the HEVC intra encoder. Each prediction unit (PU) is given a priority label out of four based on its spatial and temporal neighbor PU information as well as the predicted PU depth. Different processing strategy will be applied to different priority class, under the assumption that more computing resource should be allocated to the high priority class since its corresponding PU has the high potential to be chosen as the optima. Experiments are performed using all the common test sequences, and results show that, the encoder complexity is significantly reduced by about 4 6 % for All Intra configuration with BD-Rate (Bjontegaard Delta Rate) increase less than 0.9% for luma component. Meanwhile, compared with several recent works, our proposed solution demonstrates the well trade-off between the coding efficiency and complexity reduction.

关键词： encoding complexity Plutonium Video coding precedence bit rate reduction based

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