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On-line adaptive canonical prefix coding with bounded compression loss

IEEE TRANSACTIONS ON INFORMATION THEORY 2001年第1期47卷 88-98页

作者： Turpin, A Moffat, A Univ Melbourne Dept Comp Sci & Software Engn Melbourne Vic 3010 Australia

Semistatic minimum-redundancy prefix (MRP) coding is fast compared with rival coding methods, but requires two passes during encoding. Its adaptive counterpart, dynamic Huffman coding, requires only one pass over the input message for encoding and decoding, and is asymptotically efficient. Dynamic Huffman coding is, however, notoriously slow in practice. By removing the restriction that the code used for each message symbol must have minimum-redundancy and thereby admitting some compression loss, it is possible to improve the speed of adaptive MRP coding. This paper presents a controlled method for trading compression loss for coding speed by approximating symbol frequencies with a geometric distribution, The result is an adaptive MRP coder that is asymptotically efficient and also fast in practice.

关键词： adaptive coding Huffman coding minimum-redundancy coding (MRP) on-line coding

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adaptive Error-Correction coding Scheme for Underwater Acoustic Communication Networks

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IEEE JOURNAL OF OCEANIC ENGINEERING 2015年第1期40卷 104-114页

作者： Diamant, Roee Lampe, Lutz Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

Underwater acoustic communication networks (UWANs) have recently attracted much attention in the research community. Two properties that set UWANs apart from most radio-frequency wireless communication networks are the long propagation delay and the possible sparsity of the network topology. This in turn offers opportunities to optimize throughput through time and spatial reuse. In this paper, we propose a new adaptive coding method to realize the former. We consider time-slotted scheduling protocols, which are a popular solution for contention-free and interference-free access in small-scale UWANs, and exploit the surplus guard time that occurs for individual links for improving transmission reliability. In particular, using link distances as side information, transmitters utilize the available portion of the time slot to adapt their code rate and increase reliability. Since increased reliability trades off with energy consumption per transmission, we optimize the code rate for best tradeoff, considering both single and multiple packet transmission using the incremental redundancy hybrid automatic repeat request (IR-HARQ) protocol. For practical implementation of this adaptive coding scheme, we consider punctured and rateless codes. Simulation results demonstrate the gains achieved by our coding scheme over fixed-rate error-correction codes in terms of both throughput and consumption of transmitted energy per successfully delivered packet. We also report results from a sea trial conducted at the Haifa harbor, which corroborate the simulations.

关键词： adaptive coding incremental redundancy automatic repeat request (IR-HARQ) rateless codes underwater acoustic communication

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Block classification for an adaptive 1-D/2-D DCT video coding

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IEE PROCEEDINGS-VISION IMAGE AND SIGNAL PROCESSING 1996年第3期143卷 155-163页

作者： Tan, KH Ghanbari, M UNIV ESSEX DEPT ELECTR SYST ENGNCOLCHESTER CO4 3SQESSEXENGLAND

A classification scheme for an adaptive one- or two-dimensional discrete cosine transform (1-D/2-D DCT) technique is described and demonstrated to be a more appropriate strategy than the conventional 2-D DCT for coding motion compensated prediction error images. Two block-based classification methods are introduced and their accuracy in predicting the correct transform type discussed. The accuracy is assessed with a classification measure designed to ascertain the effectiveness of energy compaction when the predicted transform class is applied;visa-vis horizontally, vertically or two-dimensionally transformed blocks, Energy compaction is a useful property not only for efficient entropy coding but also for enhancing the resilience of the transform coder to quantisation noise. Improvements against the homogeneous 2-D DCT system both in terms of peak signal to noise ratio and subjective assessments are achieved. Observable ringing artifacts along edges, which are usual in conventional transform coding, are reduced.

关键词： video coding low bit rate coding adaptive coding DCT block classification

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An integrated framework for adaptive subband image coding

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 1999年第4期47卷 1024-1038页

作者： Pavlovic, V Moulin, P Ramchandran, K Compaq Comp Corp Cambridge Res Lab Cambridge MA 02139 USA Univ Illinois Beckman Inst Urbana IL 61801 USA Univ Illinois Dept Elect & Comp Engn Urbana IL 61801 USA

Recent work on filter banks and related expansions has revealed an interesting insight: Different filter bank trees can be regarded as different ways of constructing orthonormal bases: for linear signal expansion, In particular, fast algorithms for finding best bases in an operational rate-distortion (R/D) sense hare been successfully used in image coding, Independently of this work, recent research has also explored the design of filter banks that optimize energy compaction for a single signal or a class of signals. In this paper, we integrate these two different but complementary approaches to best-basis design and propose a coding paradigm in which subband filters, tree structure, and quantizers are chosen to optimize R/D performance, These coder attributes represent side information. They are selected from a codebook designed off-line from training data, using RID as the design criterion. This approach provides a rational framework in which to explore alternatives to empirical design of filter banks, quantizers, and other coding parameters. The on-line coding algorithm is a relatively simple extension of current R/D-optimal coding algorithms that operate,vith fixed filter banks and empirically designed quantizer codebooks. In particular, it is shown that selection of the best adapted filter bank from the codebook is computationally elementary.

关键词： adaptive coding best basis methods filter banks image compression rate-distortion methods subband coding vector quantization

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adaptive CODE EXCITED PREDICTIVE coding

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 1992年第6期40卷 1317-1326页

作者： GALAND, CR MENEZ, JE ROSSO, MM UNIV NICE SOPHIA ANTIPOLISFRANCE LASSY CNRSURA 1376EQUIPE 135F-06041 NICEFRANCE IBM CORP THOMAS J WATSON RES CTRDEPT COMP SCIYORKTOWN HTSNY 10598 IBM CORP DEPT ARCHITECTURE & TELECOMMUNRES TRIANGLE PKNC

Since its recent introduction by Atal and Schroeder, the code excited linear predictive (CELP) coder has been thoroughly and widely studied by the speech coding research community, and has already been adapted to several standards for telephone speech coding. The CELP algorithm represents a breakthrough in speech coding, for it encodes telephone quality speech at 8 kb/s without noticeable distortion. Previously, this performance was achievable by coders operating at 16 kb/s or higher. However, the drawback of the CELP is its inherent complexity, which, despite the fast progress of the technology, may represent a problem of cost or feasibility in products. In this paper, we discuss a new way to consider the CELP concept, which allows us to cut the processing load while keeping the same speech quality. Rather than performing the individual weighting of each candidate sequence, we propose a global implementation of the perceptual weighting function at the codebook level. As a result, the analysis-by-synthesis procedure does not require the processing of all the candidate sequences through the synthesis and weighting filters, and therefore the complexity requirement of the algorithm is much reduced. The new concept is carried out with an adaptive codebook. We report on two fixed-point implementations of our adaptive CELP (ACELP) algorithm: a 7.2 kb/s block coder (7 MIPS), and a 12 kb/s low-delay coder (11 MIPS). Both coders have been rated to provide the same quality as the 13 kb/s block coder adopted by the GSM for the European cellular telephone.

关键词： adaptive coding Predictive coding Filters Speech coding Telephony Speech analysis Technological innovation Signal processing Code standards Costs

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Dynamic codebook adaptive vector quantization for image coding

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 1999年第2期45卷 327-332页

作者： Feng, J Lo, KT City Univ Hong Kong Dept Elect Engn Tat Che Ave Kowloon Peoples R China Hong Kong Polytech Univ Dept Elect & Informat Engn Kowloon Peoples R China

In this paper, a new image coding scheme called dynamic codebook adaptive vector quantization (DCAVQ) is proposed. DCAVQ is designed to minimize the transmission overhead and computational complexity of existing adaptive vector quantization systems. Simulation results using real images demonstrate both subjective and objective performance of decoded images are improved using the proposed method. On the ether hand, the execution time of the system is being comparable to that of a standard universal VQ system.

关键词： Vector quantization Image coding Image reconstruction Statistics Rate-distortion Character generation Bit rate Transform coding adaptive coding

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Lossless image coding via adaptive linear prediction and classification

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PROCEEDINGS OF THE IEEE 2000年第11期88卷 1790-1796页

作者： Motta, G Storer, JA Carpentieri, B Brandeis Univ Dept Comp Sci Waltham MA 02454 USA Univ Salerno Dipartimento Informat & Applicaz RM Capocelli I-84081 Baronissi Italy

In the past years, there have been several improvements in lossless image compression. All the recently proposed state-of-the-art lossless image compressors can be roughly divided into two categories: single and double-pass compressors. Linear prediction is rarely used in the first category, while TMV [7], a state-of-the-art double-pass image compressor, relies on linear prediction for its performance. We propose a single-pass adaptive algorithm that uses context classification and multiple linear predictors, locally optimized on a pixel-by-pixel basis. Locality is also exploited in the entropy coding of the prediction error. The results we obtained on a test set of several standard images are encouraging. On the average, our ALPC obtains a compression ration comparable to CALIC [20] while improving on some images.

关键词： adaptive coding arithmetic codes data compression Golomb-Rice codes gradient methods image coding linear predictive coding

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ADPCM coding OF SPEECH SIGNAL - adaptive PREDICTION ALGORITHMS AND ASSESSMENT

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ANNALES DES TELECOMMUNICATIONS-ANNALS OF TELECOMMUNICATIONS 1983年第9-10期38卷 381-398页

作者： LEGUYADER, A GILLOIRE, A CNET-LAA-CMC Route de Trégastel 22301 Lannion

Analyse Cet article décrit des algorithmes de codage différentiel utilisant des prédicteurs à filtres en treillis pour le codage de la parole et présente leurs performances en présence ou non d’erreurs de transmission. L’analyse statistique des résultats des tests subjectifs montre que l’utilisation de ces algorithmes pour le codage de la parole permet de diviser par deux le débit numérique que nécessite le codagemic classique. L’article montre que, pour les codeurs testés, les meilleures performances subjectives sont obtenues avec des prédicteurs en treillis. Le comportement de ces algorithmes dans les configurations de codages et de transcodages multiples à partir de codesmic, que l’on peut rencontrer dans le réseau téléphonique actuel est abordé en fin d’article.

关键词： Predictive coding Speech processing Passband compression adaptive coding dpcm Autoregressive model Moving average Lattice network adaptive filter Comparative study Subjective evaluation Telephone network Digital simulation

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adaptive PREDICTION DIFFERENTIAL PCM coding FOR TELEVISION - PICTURE QUALITY, DATA RATE REDUCTION AND SENSITIVITY TO TRANSMISSION ERRORS

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ANNALES DES TELECOMMUNICATIONS-ANNALS OF TELECOMMUNICATIONS 1982年第7-8期37卷 299-324页

作者： KRETZ, F CCETT/Laboratoires du CNET 35013 Rennes 1266 Cedex BP France

AnalyseCet article est consacré à l’étude des algorithmes de codage d’images de télévision du type MICdifférentiel à prédiction adaptative. L’adaptativité peut jouer sur... 详细信息

Analyse Cet article est consacré à l’étude des algorithmes de codage d’images de télévision du type MICdifférentiel à prédiction adaptative. L’adaptativité peut jouer sur le prédicteur et aussi sur le quantificateur. L’auteur pose le problème et rappelle les propriétés de la source (structure des images) qui serviront de base à l’adaptativité du prédicteur. Divers algorithmes de prédiction adaptative sont décrits et certaines de leurs caractéristiques telles que l’efficacité en réduction de la dynamique de l’erreur de prédiction et la susceptibilité aux erreurs de transmission sont comparées. Une annexe traite de l’optimalisation d’un prédicteur fixe selon deux types de critère.

关键词： Picture coding Transient picture Predictive coding adaptive coding Differential PCM Picture quality Data compression Transmission error adaptive algorithm Edge

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ERROR TOLERANT adaptive ALGORITHMS FOR DELTA-MODULATION coding

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IEEE TRANSACTIONS ON COMMUNICATIONS 1980年第3期28卷 385-391页

作者： DODDS, DE SENDYK, AM WOHLBERG, DB DEPT COMMUN COMMUN RES CTROTTAWA K1N 8T5ONTARIOCANADA SED SYST LTD DIV SYSTSASKATOONSASKATCHEWANCANADA

This paper investigates the adaption of qnantizer step size in voice coding circuits. Techniques which maintain the decoder step size in the presence of channel errors have been evaluated. Graphs are presented for the comparison of error recovery performance. Practical considerations favor one algorithm, and its digital implementation has been described in the paper. Laboratory measurements of step-size error recovery and SNR performance have been included to verify the theory.

关键词： adaptive algorithm Decoding adaptive coding Codecs Quantization Data communication Communications Society Councils Circuits Laboratories

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