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IEEE International Conference on Image Processing

作者： M. Gallant F. Kossentini Department of Electrical and Computer Engineering University of British Columbia Vancouver BC Canada

ISBN: (纸本)0780362977

We present a rate-distortion optimal joint source/channel coding framework for efficient and robust low bit rate video communications in packet networks. The proposed algorithm combines layered coding with transport prioritization in a novel operational rate-distortion optimization framework that trades off source coding performance for channel coding protection. The system is demonstrated to achieve significant improvement in reconstructed video quality for a range of packet loss rates.

关键词： Rate-distortion Robustness Bit rate Channel coding source coding Forward error correction Decoding Propagation losses Streaming media Error correction codes

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Modeling of operational distortion-rate characteristics for joint source-channel coding of video

Modeling of operational distortion-rate characteristics for ...

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IEEE International Conference on Image Processing

作者： M. Bystrom T. Stockhammer ECE Department Drexel University Philadelphia PA USA Department for Communications Engineering Munich University of Technology Munich Germany

ISBN: (纸本)0780362977

We present a method for modeling the distortion-rate characteristics of compressed video sequences. It is assumed that the source coders rely on motion-compensated prediction, and thus error propagation will contribute significantly to the degradation of the reconstructed video. It is shown that through the use of the modeled characteristics source and channel coding rate can be allocated across frames in a video sequence in order to minimize the effects of error propagation.

关键词： source coding Video compression Video sequences Channel coding Decoding Character generation Degradation Image reconstruction Code standards Standards development

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On encoding of position information in inter-vehicle communications

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IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS 2002年第11期E85D卷 1822-1829页

作者： Goto, Y Hasegawa, T Saitama Univ Dept Elect & Elect Syst Engn Urawa Saitama 3388570 Japan

This paper discusses encoding of vehicular position information using predictive algorithms in inter-vehicle communications (IVC) from the viewpoints of source coding and noisy channels. Two vehicular driving models are assumed;one is the 15-mode as a suburban rapid transit driving pattern, the other is called calming mode as a street-driving pattern. Three types of schemes are compared;a pulse code modulation (PCM) scheme, a predictive coding (PC) scheme, and the variable interval prediction (VIP) scheme that is proposed here. This paper assumes that precise position information is got from a positioning system, and that all the transmitters and receivers have common predictors. Performance comparisons of the three types of schemes are carried out both of noiseless and noisy channels. Results show that the VIP scheme is superior to any other scheme.

关键词： ITS inter-vehicle communications predictive algorithms position information source coding

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Memory vector quantization by power series expansion [in speech coding]

Memory vector quantization by power series expansion [in spe...

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IEEE Workshop on Speech coding Proceedings

作者： T. Eriksson F. Norden Chalmers University of Technology Goteborg Sweden

Memory quantization is studied in detail. We propose a framework, power series vector quantization (PSVQ), for analysis and development of memory quantizers. Furthermore, we present an optimization algorithm for the framework, and new memory quantization methods are derived from the framework. The new methods are applied to spectrum quantization, and are shown to outperform previous methods.

关键词： Vector quantization Decoding source coding Speech coding History Linear predictive coding Nonlinear distortion Distortion measurement Equations Algorithm design and analysis

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The use of multiple description coding in networking

The use of multiple description coding in networking

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IEEE International Symposium on Information Theory

作者： M. Alasti K. Sayrafian-Pour A. Ephremides N. Farvardin Zagros Networks Rockville MD USA Department of Electrical & Computer Engineering University of Maryland College Park MD USA

Consider a memoryless, loss-tolerant and delay-sensitive source, the output of which is transmitted through a packet-switched communication network. Network parameters such as congestion, route quality, link capacity etc., have a great impact on the achievable distortion at the receiver. In our previous publication (see IEEE Trans. on Inform. Theory, vol.47, no.3, p.891-903, March 2000)., we investigated the significance of using multiple description coding (MDC) in reducing the average end-to-end distortion. Also we demonstrated the value of intelligent routing in reducing distortion for single description coding. In this paper, we show that the relative improvement that is achieved by using intelligent routing is much more noticeable in systems employing MDC.

关键词： Intelligent networks Switches Packet switching Traffic control Routing Telecommunication traffic Intelligent systems source coding Propagation losses Educational institutions

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Quantizers with uniform encoders and channel optimized decoders

Quantizers with uniform encoders and channel optimized decod...

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Data Compression Conference (DCC)

作者： B. Farber K. Zeger University of California San Diego USA

ISBN: (纸本)0769514774

Scalar quantizers with uniform encoders and channel optimized decoders are studied for uniform sources and binary symmetric channels. It is shown that the natural binary code and folded binary code induce point density functions that are uniform on proper subintervals of the source support, whereas the Gray code does not induce a point density function. The mean squared errors for the natural binary code, folded binary code, Gray code, and for randomly chosen index assignments are calculated and the natural binary code is shown to be mean squared optimal among all possible index assignments. In contrast, it is shown that almost all index assignments perform poorly and have degenerate codebooks.

关键词： Decoding Binary codes Reflective binary codes Density functional theory System performance Error correction source coding Channel coding Added delay Telephony

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MAP criterion image coding using the BCJR algorithm

MAP criterion image coding using the BCJR algorithm

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IEEE International Symposium on Information Theory

作者： T. Eriksson M. Novak J.B. Anderson Dept. of Information Technology Lund University Lund Sweden

BCJR based source coding of image residuals is explored. From a trellis representation of the residual, a joint source-channel coding system is formed. The use of the BCJR algorithm is possible due to a procedure which transforms the residuals to a representation with independent identically distributed components having unit variance.

关键词： Image coding Convolutional codes source coding Convolution Information technology Polynomials Channel coding Quantization Distortion measurement Q measurement

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Joint error control and power allocation for video transmission over CDMA networks with multiuser detection

Joint error control and power allocation for video transmiss...

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IEEE International Conference on Communications (ICC)

作者： Shengjie Zhao Zixiang Xiong Xiaodong Wang Department of Electrical Engineering Texas A and M University College Station TX USA

ISBN: (纸本)0780374002

Error control and power allocation for transmitting wireless video over CDMA networks are considered in conjunction with multiuser detection. We map a layered video bitstream to several CDMA fading channels and inject multiple source/parity layers into each of these channels at the transmitter. At the receiver, we employ a linear minimum mean-square error (MMSE) multiuser detector in the uplink and two types of blind linear MMSE detectors in the downlink, for demodulating the received data. For given constraints on the available bandwidth and transmit power, the transmitter determines the optimal power allocation among different CDMA fading channels and the optimal number of source and parity packets to send that offer the best video quality. Simulation results show a performance gain of up to 1.5 dB with joint optimization over that with rate optimization only.

关键词： Error correction Multiaccess communication Detectors Bit error rate Forward error correction source coding Video coding Multiuser detection Fading Transmitters

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Csiszar's forward cutoff rate for testing between two arbitrary sources

Csiszar's forward cutoff rate for testing between two arbitr...

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IEEE International Symposium on Information Theory

作者： F. Alajaji Po-Ning Chen Z. Rached Department of Mathematics & Stats Queen's University Kingston Canada Department of Communication Engineering National Chiao Tung University Taiwan

The Csisza forward /spl beta/-cutoff rate (/spl beta/<0) for hypothesis testing is defined as the largest rate R/sub 0//spl ges/0 such that for all rates 0

关键词： Testing Error probability Councils source coding Entropy

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JPEG 2000: performance and evaluation

JPEG 2000: performance and evaluation

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IEEE International Conference on Systems, Man and Cybernetics

作者： A. Samet M.A. BenN Ayed M.S. Bouhlel M. Loulou N. Masmoudi L. Kamoun Laboratoire d'Electronique et des Technologies de l'Information (LETI) Ecole Nationale d'Ingénieurs de Sfax Sfax Tunisie Ecole Nationale d'Ingenieurs de Sfax Sfax TN Lab. d'Electronique et des Technol. de l'Inf. Ecole Nationale d'Ingenieurs de Sfax Tunisia

With the increasing usage of multimedia technologies, image compression requires higher performance as well as new features. To address these needs in the specific area of continuous tone still image encoding, a new standard is currently being developed, JPEG2000. We first present an overview of this standard. We are interested in evaluation of its performance by means of Kakadu software.

关键词： Image coding Codecs Transform coding Code standards Standards development ISO standards Propagation losses Discrete wavelet transforms source coding Digital images

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