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5th International Conference on Signal Processing and Communication Systems (ICSPCS)

作者： Zheng, Xiguang Ritz, Christian Univ Wollongong Sch Elect Comp & Telecommun Engn Wollongong NSW 2522 Australia

ISBN: (纸本)9781457711800

Real-time audio-visual communication requires a packet-loss recovery mechanism due to inevitable packet loss characteristics of the transmission channel such as the Internet. Especially for interactive applications e. g. real-time audio-visual communication, the delay for the recovery and enhancement technology must be minimized. Among the low-delay packet-loss recovery techniques, multiple description coding (MDC) and Forward Error Correction (FEC) are widely used for their robustness and efficiency. This paper proposes three new MDC-FEC models to minimize the overall distortion subject to specific source coding rates and channel packet loss probabilities. The proposed solution would enable adaptive selection of an optimal packet-loss recovery mechanism based on real-time feedback of channel conditions. The results indicate that this approach leads to an optimal model for joint source-channel coding based on a combination of MDC and FEC.

关键词： multiple description coding Forward Error Correction Packet Loss Recovery Multimedia Communication

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Distribution Preserving Quantization

Distribution Preserving Quantization

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作者： Minyue Li KTH Royal Institute of Technology

学位级别：博士

In the lossy coding of perceptually relevant signals, such as sound and im- ages, the ultimate goal is to achieve good perceived quality of the recon- structed signal, under a constraint on the bit-rate. Conventional method- ologies focus either on a rate-distortion optimization or on the preservation of signal features. Technologies resulting from these two perspectives are efficient only for high-rate or low-rate scenarios. In this dissertation, a new objective is proposed: to seek the optimal rate-distortion trade-off under a constraint that statistical properties of the reconstruction are similar to those of the source. The new objective leads to a new quantization concept: distribution preserving quantization (DPQ). DPQ preserves the probability distribution of the source by stochastically switching among an ensemble of quantizers. At low rates, DPQ exhibits a synthesis nature, resembling existing cod- ing methods that preserve signal features. Compared with rate-distortion optimized quantization, DPQ yields some rate-distortion performance for perceptual benefits. The rate-distortion optimization for DPQ facilitates mathematical anal- ysis. The dissertation defines a distribution preserving rate-distortion func- tion (DP-RDF), which serves as a lower bound on the rate of any DPQ method for a given distortion. For a large range of sources and distortion measures, the DP-RDF approaches the classic rate-distortion function with increasing rate. This suggests that, at high rates, an optimal DPQ can ap- proach conventional quantization in terms of rate-distortion characteristics. After verifying the perceptual advantages of DPQ with a rela- tively simple realization, this dissertation focuses on a method called transformation-based DPQ, which is based on dithered quantization and a non-linear transformation. Asymptotically, with increasing dimensional- ity, a transformation-based DPQ achieves the DP-RDF for i. i. d. Gaussian sources and the mean squared error (MSE)

关键词： lossy source coding perceived quality perceptual coding rate-distortion function quantization synthesis distribution preserving quantization distribution preserving rate-distortion function multiple description coding entropy coding

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A Novel Layered Error Resilient Method for SPIHT-Coded Images over Packet Networks

A Novel Layered Error Resilient Method for SPIHT-Coded Image...

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International Conference on Industry, Information System and Material Engineering

作者： Sun, WenZhu Wang, HongYu Wang, Jie Dalian Univ Technol Fac Elect Informat & Elect Engn Dalian 116023 Peoples R China

ISBN: (纸本)9783037850275

This paper presents a layered error resilient scheme for Set Partitioning in Hierarchical Trees (SPIHT) coding which incorporates the multiple description coding (MDC) into the data partition. The major feature of this scheme is that the MDC is adopted in the process of packetizing the spatial orientation trees, so as to protect the important information bits according to different importance and channel state. The proposed scheme can allocate redundancy accurately and flexibly, by differentiating importance of bits through different bit planes. Experimental results show that the proposed method achieves good performance over packet erasure channels.

关键词： Error-resilience multiple description coding bit plane coding set partitioning in hierarchical trees (SPIHT) joint source-channel coding

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Service Availability for P2P on-demand Streaming with Dynamic Buffering

Service Availability for P2P on-demand Streaming with Dynami...

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17th IEEE International Conference on Parallel and Distributed Systems (ICPADS)

作者： Lin, Chow-Sing Yan, Meng-Jia Natl Univ Tainan Dept Comp Sci & Informat Engn Tainan 700 Taiwan

ISBN: (纸本)9780769545769

In general, on-demand video services enable clients to watch videos from beginning to end. As long as clients are able to buffer the initial part of the video they are watching, on-demand service can provide access to the video to the next clients who request to watch it. In our previous research work, we proposed a novel caching scheme for peer-to-peer on-demand streaming, called Dynamic Buffering. The dynamic buffering relies on the feature of multiple description coding to gradually reduce the number of cached descriptions held in a peer's buffers once the buffer is full. In this paper(1), we proposed three description dropping policies for dynamic buffering, called sequence dropping, m-dropping, and binary dropping. Mathematical formulas of the reduced number of buffer adjustments of descriptions and the reduction of the average number of selectable descriptions for m-dropping and binary dropping by factors of n and m were established in the paper. Experimental results showed that the m-dropping, m=inverted right perpendicularn/2inverted left perpendicular generally outperformed m-dropping, m=2 and binary dropping in terms of service availability. Even though the accumulated reduction of buffer adjustments for m-dropping polices was less than that for binary dropping, the average number of selectable descriptions for m-dropping was much greater than that for binary dropping.

关键词： dynamic buffering service availability multiple description coding peer-to-peer streaming

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Coded Wireless Video Broadcast/Multicast: A Cross-layer Framework and End-to-End Distortion Analysis

Coded Wireless Video Broadcast/Multicast: A Cross-layer Fram...

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7th ACM Workshop on Wireless Multimedia Networking and Computing

作者： She, James Yang, En-hui Ho, Pin-Han Univ Cambridge Comp Lab Cambridge CB3 0FD England

ISBN: (纸本)9781450309035

A cross-layer framework of interplay between multiple description coding (MDC) at the source and layered modulation using superposition coding (SPC) at the channel has recently been proposed as an effective approach to mitigate the vicious effects due to multi-user diversity and fast Rayleigh fading in wireless video broadcast/ multicast. However, there has not been a rigorous and general end-to-end distortion analysis to determine if and when such interplay between the protection code (such as MDC) in the upper layer and the multi-resolution modulation by way of SPC in PHY/MAC layer for transmitting successively refined information can lead to a better end-to-end distortion performance than other possibilities. The paper provides a comprehensive information theoretical analysis on the end-to-end distortion. Mathematical proofs are derived to confirm the advantages and conditions of such cross-layer systems to always give the better distortion performance. Numerical analysis is conducted to verify the mathematical conclusions while unveiling some interesting observations.

关键词： Wireless broadcast/ multicast cross-layer design superposition modulation multiple description coding scalable video coding

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multiple description video coding using coefficients ordering and interpolation

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2007年第3期22卷 252-265页

作者： Conci, Nicola De Natale, Francesco G. B. Univ Trent Dept Informat & Commun Technol I-38100 Trento Italy

A multiple description Video Codec is presented, suitable for high-quality digital video transmission. The method works in the DCT domain, and associates to each descriptor two data sources: a subset of the original transform coefficients, and side information concerning the position and magnitude of the remaining coefficients. When one or more descriptors are (partially) lost, the side information is used at the decoder to interpolate the missing coefficients, thus achieving a better reconstruction. The effectiveness of the proposed approach is greatly enhanced by the use of a JPEG-like syntax and an efficient 3D-VLC in the encoding of the overhead information. This choice makes also easier and natural the integration of the MDC scheme in most DCT-based standard encoders such as M-JPEG and MPEG-1/2. With respect to previous approaches to MDC, the proposed strategy is characterized by a limited overhead and a reduced impact in terms of computational complexity. Furthermore, the coefficient selection strategy allows splitting the video stream into an arbitrary number of descriptors, overcoming a major limitation of most MDC schemes. These features make the proposed method suitable for real-time applications of video delivery, especially in wireless environments where the computational complexity is usually performed by low-power devices. As far as the reconstruction quality is concerned, extensive experimental sessions demonstrated that the loss of one descriptor produces a slight degradation in a two-descriptors scheme, while it is almost seamless in a three-descriptors scheme. (c) 2007 Elsevier B.V. All rights reserved.

关键词： multiple description coding video streaming error resilience

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Efficient Video Streaming in Wireless P2P Network Using HIS-MDC Technique

Efficient Video Streaming in Wireless P2P Network Using HIS-...

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2nd International Conference on Advances in Communication, Network, and Computing (CNC 2011)

作者： Eranti, Jeevan Jaganathan, Suresh Srinivasan, A. Sri Sivasubramania Nadar Coll Engn Dept Comp Sci & Engn Chennai Tamil Nadu India Misrimal Navajee Munoth Jain Engn Coll Dept Comp Sci & Engn Chennai Tamil Nadu India

ISBN: (纸本)9783642195419

In this paper, we propose a technique which enhances continuous flow of streaming despite packet loss, error resilience and quality of service using multiple descriptions coding (MDC). The main aim of MDC is to encode a video into multiple frames called descriptions, supporting multiple stages of decoding and when compared to layered coding techniques, each description can be decoded separately to estimate the model. In this proposed work we improve the error resilience and user heterogeneity using new multiple description coding method called Hybrid Interpolation Scalable MDC (HIS-MDC) technique and using both spatial and temporal interpolation schemes corrupted portions of a frame are concealed. Experimental results show that, proposed approach attains reasonable quality of video performance compared with previous multiple description methods.

关键词： interpolation peer-to-peer wireless network multiple description coding video streaming

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Video Broadcasting over Heterogeneous Networks 1

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International Conference on Computer Science and Education (CSE 2011)

作者： Gao, Zhuo Sun, Xuemei Beijing Informat Sci & Technol Univ Beijing 100192 Peoples R China Calif State Polytech Univ Pomona Pomona CA 91768 USA

ISBN: (数字)9783642224560

ISBN: (纸本)9783642224553

A new scheme is proposed for broadcasting video signals over heterogeneous networks. The scheme is based on multiple-description coding (MDC) and aims to suppress the threshold effect. Each description is independently generated and can he used alone or together with other descriptions to reconstruct the video signal. The performance trade-off is analyzed in an information theoretic manner and it is shown that the performance of the proposed scheme approaches the optimum rate-distortion bound under certain source and channel assumptions. Practical simulation results with video signals are provided and discussed.

关键词： video broadcasting heterogeneous network multiple description coding threshold effect suppression

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Real-time multiple description intra-coding by sorting and interpolation of coefficients

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Signal, Image and Video Processing 2007年第1期1卷 1-10页

作者： Conci, Nicola De Natale, Francesco G. B. Department of Information and Communication Technology University of Trento Trento Italy

A novel approach to multiple description coding (MDC) of digital video is presented. In the proposed scheme, each descriptor carries a limited number of alternately selected coefficients, complemented with sorting information, which is used at the decoder to achieve an accurate interpolation of missing coefficients. In order to achieve an efficient compression reducing the overhead, a very effective JPEG-like syntax has been introduced to encode the side information. As compared to other approaches to MDC, the proposed strategy is characterized by an extremely low computational burden, while ensuring comparable overhead and almost seamless reconstruction from a single descriptor. Current implementation refers to a two-descriptors architecture, and is tested on intra-frames only, using a M-JPEG scheme for the simulation. Further studies are being conducted to extend the method to more descriptors and motion-compensated video coding. © 2007 Springer-Verlag London Limited.

关键词： Error resilience multiple description coding Video streaming

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multiple description wavelet coding with dual decomposition and cross packetization

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Signal, Image and Video Processing 2007年第1期1卷 53-61页

作者： Cai, Canhui Chen, Jing Ma, Kai-Kuang Mitra, Sanjit K. Institute of Information Science and Engineering Huaqiao University Quanzhou Fujian 362021 China School of Electrical and Electronic Engineering Nanyang Technological University Singapore 639798 Singapore Department of Electrical and Computer Engineering University of California Santa Barbara CA 93106-9560 United States

In this paper, a novel wavelet-based multiple description coding (MDC) is proposed with dual decomposition (DD) and cross packetization (CP). Through dual decomposition, each description has two parts, the primary and the complementary. The former contains the structural information, including the positions and signs of significant coefficients, whereas the latter contains the residual data, which are the absolute values of the significant coefficients' magnitude. The primary part is most crucial for source reconstruction;hence, their codes generated by the x-tree wavelet encoder are duplicated in both descriptions for heavy protection. On the other hand, the residual data are processed by the multiple description scalar quantizer to generate two indices for their respective descriptions as the complementary part. The proposed DD-MDC method effectively enhances error-resilience capability for robust transmission. For the packet-switching networks, the proposed CP, which produces the row packets and column packets for the two descriptions, respectively, is incorporated into the DD-MDC framework, leading to the DDCP-MDC scheme. Extensive simulation results have clearly shown that the proposed wavelet-based DD-MDC and DDCP-MDC methods are highly error resilient and consistently yield high coding gain;particularly, when only one description is available, the reconstructed image quality is superior to that obtained with other existing methods. © 2007 Springer-Verlag London Limited.

关键词： Decomposition Error-resilient coding multiple description coding Packet switching networks Packetization X-tree

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