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JPEG based scalable image compression

COMPUTER COMMUNICATIONS 1996年第12期19卷 1001-1013页

作者： Panchanathan, S Gamaz, N Jain, A Visual Computing and Communications Laboratory Department of Electrical Engineering University of Ottawa Ottawa Ontario Canada K1N 6N5

In this paper, we present JPEG-based scalable image compression algorithms for storage and transmission applications. The JPEG standard for still image compression provides the framework for reconstructing images in different sizes and picture qualities. These features are generally referred to as spatial and SNR scalability, respectively, and are extremely important in a variety of applications. A review of the different modes of the JPEG standard followed by the implementation and performance evaluation of the progressive and hierarchical coding modes which provide SNR and spatial scalability, respectively, are detailed. We then present a highperformance technique based on Wavelet filter downsampling for achieving spatial scalability within the framework of the hierarchical mode of the JPEG standard. This technique provides substantial improvement in performance while maintaining the compatibility with existing JPEG decoders.

关键词： compression image browsing scalability JPEG wavelet progressive coding hierarchical coding

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Low delay coder (<25 ms) of wideband audio (20 Hz-15 kHz) scalable from 64 to 32 kbit/s

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ANNALS OF TELECOMMUNICATIONS 2000年第9-10期55卷 493-506页

作者： Moreau, N Dymarski, P Ecole Natl Super Telecommun Bretagne TSI F-75634 Paris 13 France Warsaw Univ Technol PL-00665 Warsaw Poland

A low delay coder for speech and music signals sampled at 32 kHz is described. Its algorithmic delay does not exceed 25 ms which enables audio conferencing applications without echo cancellation. Its bot rate is scalable between 64 and 32 kbits/s by steps of 8 kbits/s. The transmitter issues the binary code at 64 kbits/s with lower bit rate codes embedded in it. The receiver may operate at lower bit rates with gradual loss of quality. The proposed coder is based on a mixed scheme: the adopted solution contains elements from the CELP speech coder and frequency domain where bit allocation is calculated and transform coefficients are quantized. A first solution based on the DFT is discussed, then a second solution based on a MDCT with small overlap is applied. The quantization of these coefficients is done in the following way. First, a prediction of the whole spectrum is applied. Then, a mean-removed gain-shape split VQ is used for amplitude spectrum quantization and a hierarchical 2-dimensional VQ is used for phase spectrum quantization stage, each codeword describing the selected vector index is split into parts corresponding to different bit rates. Due to the hierarchical codebook structure, truncated indices may be used, without much affecting the signal quality. Simulation results are presented and the robustness of the proposed coder is examined.

关键词： speech coding sound coding hierarchical coding sound quality perception passband compression coder music signal spectrum signal quantizing scability

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Intermediate Description for Multiple Video Adaptation

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 2009年第2期55卷 919-926页

作者： Shen, Qiu Guo, Yi Li, Houqiang Wu, Feng Univ Sci & Technol China Dept Elect Engn & Informat Sci Hefei Peoples R China Microsoft Res Asia Beijing 100190 Peoples R China

Video adaptation has been considered as a promising technique to tackle challenging problems in pervasive media applications. However, the style of video representation and description in current framework is too simple to accommodate diversified usages, especially for real-time application environment. In this paper, an intermediate video description termed Intermedia is proposed, which is generated by off-line pre-processing the original video signal and includes abundant information of video content. On the basis of Intermedia, a novel framework for video adaptation can be implemented to handle multiple video applications. The framework has low complexity operations not only in signal level, but also in structural level, and in joint level. Texture, motion and structural characteristic are included in Intermedia, so that the framework call tackle a number of different adaptation applications, e.g., bit-rate conversion, temporal resolution reduction, video summarization browsing, and multi-dimensional adaptation. Experimental results demonstrate that Intermedia can support multiple video adaptations rapidly while maintaining coding efficiency(1).

关键词： Intermedia video adaptation texture compression motion description hierarchical coding structural characteristic

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Image database system featuring graceful oblivion

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IEICE TRANSACTIONS ON COMMUNICATIONS 1996年第8期E79B卷 1015-1022页

作者： Yasuda, Y Yasuno, T Katayama, F Toida, T Sakata, H WASEDA UNIV GRAD SCH SCI & ENGN TOKYO 169 JAPAN

Intending to contribute to constructing better multimedia network systems, we propose a new concept of image database system of which form of storage is featuring exponential or graceful oblivion and abrupt recollection like the human memory property. By virtue of this property of database storages that is realized by employing hierarchical or pyramidal image coding, the database memory and transmission costs can be significantly reduced. In this paper we will describe the details of the concept, the results of theoretical analysis based on a simplified model which reveals the effectiveness of the proposed system, the structure of an experimental prototype system and the result of an experimental image retrieval service carried out by implementing it over ATM high speed channels.

关键词： multimedia on demand image database human memory model distributed system B-ISDN hierarchical coding JPEG

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Optimal pyramidal and subband decompositions for the hierarchical representation of vector valued signals

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SIGNAL PROCESSING 1998年第1期65卷 55-71页

作者： Strintzis, MG Tzovaras, D Univ Thessaloniki Dept Elect & Comp Engn Thessaloniki 54006 Greece

Filters are determined which achieve optimal pyramidal decomposition of vector signals by minimising the variance of the errors between successive pyramid levels. Further, the filters are also determined which minimize the error produced when only one of the channels is retained from a multi-channel. perfect reconstruction filter bank. The effect of either decomposition is to ensure that the lower-resolution image produced by the pyramid or the primary subband, bears maximum resemblance to the input image. This property is needed in applications requiring hierarchical (scalable, progressive) coding of vector fields. The noiseless case is examined first. Given arbitrary filters in one of the analysis or synthesis stages of the pyramid or the filter bank, the optimal corresponding synthesis, respectively analysis filters, are determined. Further, the globally optimal pairs of analysis and synthesis filters are determined. It is seen that under noiseless or lossless transmission conditions, the two above decomposition methods are optimised by identical families of analysis and synthesis filters. This is not the case if it is assumed that additive transmission noise corrupts the downsampled signal prior to the synthesis stage. This noise may represent transmission noise or the effect of quantisation between the analysis and synthesis stages. Given arbitrary analysis filters and arbitrary noise characteristics, the optimal synthesis filters are then determined for each decomposition method. The results are initially presented for the binary case and subsequently generalized to the case of M-factor pyramids and M-channel filter banks. (C) 1998 Elsevier Science B.V. All rights reserved.

关键词： hierarchical coding vector-valued signals multichannel signals optimal pyramid optimal subband filter bank

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Low-Complexity Multi-Stream Space-Time Codes-Part II: Unitary-Transform Codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2012年第2期60卷 375-383页

作者： Hochwald, Bertrand Stauffer, Erik Univ Notre Dame Dept Elect Engn Notre Dame IN 46556 USA Broadcom Corp Sunnyvale CA USA

We examine the design of space-time codes that allow simple encoding and decoding of high and low-priority streams of data. This paper comprises two parts. In the first part we introduce the system model, establish performance and complexity criteria, and introduce "direct-sum" codes that combine existing space-time codes with hierarchical modulation. In this second part, we show that the direct-sum codes of the first part can be greatly improved upon by non-direct-sum designs. We demonstrate unitary-transform codes for two and four antennas. In particular, one such code performs 4 dB better than the direct-sum Alamouti code, with per-bit decoding complexity on one stream that is a bounded function of the rate of the other stream.

关键词： Space-time coding broadcast hierarchical coding multi-stream

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New use of spatial information for content-based image indexing

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ANNALS OF TELECOMMUNICATIONS 2002年第9-10期57卷 943-957页

作者： Dombre, J Richard, N Fernandez-Maloigne, C Lab IRCOM SIC F-86962 Futuroscope France

Most indexing systems are based on global image descriptors. Nowadays, new representations are used. They try to describe images more precisely without exploiting any semantic description. They use local statistics and their relationships in the image. In this paper we present these approaches and introduce a new representation system based on a pyramidal graph. First results are also presented which show that the proposed structure is very promising for both partial and global requests.

关键词： image indexation image description object oriented method data structure hierarchical coding image segmentation

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Computation of nonequilibrium high-temperature axisymmetric boundary-layer flows

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JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER 2002年第4期16卷 490-497页

作者： Barbante, PF Degrez, G Sarma, GSR Von Karman Inst Fluid Dynam B-1640 Rhode St Genese Belgium Deutsch Zentrum Luft & Raumfahrt D-37073 Gottingen Germany Free Univ Brussels B-1050 Brussels Belgium

Efficient and accurate Hermitian-type multipoint finite difference methods are used to develop a general boundary-layer code for analyzing reacting flows around bodies of revolution. The main motivation is to build a reliable code that can be used for the investigation of the influence of different physico-chemical models for transport properties, chemical kinetics, and finite rate wall catalysis on practically relevant quantities like heat flux and skin friction at the body surface. Special care has been devoted to the correct modeling of diffusion fluxes, an aspect that is often neglected in literature. The exact Stefan-Maxwell equations are used to model the diffusion fluxes and are solved with an efficient iterative technique. Finite rate catalysis is an important aspect of thermal protection system (TPS) materials studies, for which a boundary-layer code is a very useful tool because it allows the computation of the heat flux at a cost that is a fraction of a Navier-Stokes approach. Wall catalyticity effects are taken into account by means of a model that allows one to express a suitable set of wall reactions with the associated reaction-rate probabilities. Computations performed on a variety of problems and the results shown here on some typical test cases indicate the ability and reliability of the code to cope with a wide range of nonequilibrium conditions, making it a potentially useful tool for physico-chemical and TPS material studies.

关键词： Nonequilibrium Codes CASING INSPECTION Skin friction transaction processing system nonequilibrium conditions diffusion flux wall Body Surface AXISYMMETRIC hierarchical coding transport properties Heat flux

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Control mechanisms to improve the robustness of MPEG-2 based communications over ATM networks

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ANNALS OF TELECOMMUNICATIONS 2000年第5-6期55卷 288-301页

作者： Cuenca, P Orozco-Barbosa, L Garrido, A Quiles, F Univ Castilla La Mancha Dept Informat Albacete 02071 Spain Univ Ottawa Sch Informat Technol & Engn Ottawa ON K1N 6N5 Canada

Audio-visual and other multimedia services are seen as important source of traffic for ATM networks. Due to the statistical multiplexing schemes used by ATM networks, cells are exposed to delays, jitters and losses. These phenomena affect the quality of the service provided to the video-based applications, In this paper, we introduce a set of control mechanisms at different levels of the protocol architecture. These mechanisms have been particularly tailored to better support MPEG-2-based video communications applications using ATM networks as their underlying transmission mechanism. We show that the use of errorconcealment mechanisms prove more effective when supplemented by a structural set of protocol mechanisms. We study the impact of cell losses on the quality of MPEG-2 video sequences and provide an evaluation of the quality of the decoded video as perceived by the end user. Our results demonstrate the effectiveness of the proposed protocol architecture in improving the quality of service provided to the video application.

关键词： videocommunication service ATM image coding MPEG transmission protocol quality of service picture quality error concealment hierarchical coding flow control priority system

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Application level framing applied to image compression

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ANNALES DES TELECOMMUNICATIONS-ANNALS OF TELECOMMUNICATIONS 2002年第5-6期57卷 502-519页

作者： Iren, S Amer, PD Marconi Plc Warrendale PA 15086 USA Univ Delaware Dept Comp & Informat Sci Newark DE 19716 USA

Two well-known wavelet zerotree encoding algorithms, Embedded Zerotree Encoding (EZW) and Set Partitioning in hierarchical Trees (SPIHT), provide excellent progressive display when images are transmitted over reliable networks. However, both algorithms are state-dependent and can perform poor;y over unreliable networks. We apply the concept of network-conscious image compression to the SPIHT wavelet zerotree encoding algorithm, to improve its performance over unreliable networks. Experimental results confirm the utility of network-conscious image compression concept.

关键词： image compression hierarchical coding image coding wavelet expansion transmission error system robustness packet transmission lossy system

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