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Adaptive source-channel subband video coding for wireless channels

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 1998年第9期16卷 1830-1839页

作者： Srinivasan, M Chellappa, R Univ Maryland Dept Elect Engn College Pk MD 20742 USA Univ Maryland Ctr Automat Res College Pk MD 20742 USA

This paper presents a general framework for combined source-channel coding within the context of subband coding. The unequal importance of subbands in reconstruction of the source is exploited by an appropriate allocation of source and channel coding rates for the coding and transmission of subbands over a noisy channel, For each subband, the source coding rate as well as the level of protection (quantified by the channel coding rate) are jointly chosen to minimize the total end-to-end mean-squared distortion suffered by the source. This allocation of source and channel coding rates is posed as a constrained optimization problem, and solved using a generalized bit allocation algorithm. The optimal choice of source and channel coding rates depends on the state of the physical channel. These results are extended to transmission over fading channels using a finite state model, where every state corresponds to an additive white Gaussian noise (AWGN) channel. A coding strategy is also developed that minimizes the average distortion when the channel state is unavailable at the transmitter. Experimental results are provided that demonstrate application of these combined source-channel coding strategies on video sequences.

关键词： coding for noisy channels combined source-channel coding finite-state channels robust source coding transmission over noisy channels video

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Generalized multiple description coding with correlating transforms

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IEEE TRANSACTIONS ON INFORMATION THEORY 2001年第6期47卷 2199-2224页

作者： Goyal, VK Kovacevic, J Bell Labs Murray Hill NJ 07974 USA

Multiple description ND) coding is source coding in which several descriptions of the source are produced such that various reconstruction qualities are obtained from different subsets of the descriptions. Unlike multiresolution or layered source coding, there is no hierarchy of descriptions;thus, MD coding is suitable for packet erasure channels or networks without priority provisions. Generalizing work by Orchard, Wang, Vaishampayan, and Reibman, a transform-based approach is developed for producing AT descriptions of an N-tuple source, M less than or equal to N. The descriptions are sets of transform coefficients, and th transform coefficients of different descriptions are correlated so that missing coefficients can be estimated. Several transform optimization results are presented for memoryless Gaussian sources, including a complete solution of the N = 2, M = 2 case with arbitrary weighting of the descriptions. The technique is effective only when independent components of the source have differing variances. Numerical studies show that this method performs well at low redundancies, as compared to uniform MD scalar quantization.

关键词： erasure channels integer-to-integer transforms packet networks robust source coding

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Multilayered protection of embedded video bitstreams over binary symmetric and packet erasure channels

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2005年第3期16卷 359-378页

作者： Cho, SD Pearlman, WA Rensselaer Polytech Inst Ctr Image Proc Res Dept Elect Comp & Syst Engn Troy NY 12180 USA

This paper presents a multilayered protection of embedded video bitstreams over bit errors and packet erasure channels using Error Resilient and Error Concealment 3-D SPIHT (ERC-SPIHT) algorithm, which is based on the 3-D SPIHT concepts. A robust source coder is created to give error resilience in source level of the codestream. This robustness is achieved by partitioning the wavelet coefficients into many independent sub-bitstreams while maintaining spatio-temporal tree structures. For higher protection against channel noise, we use a product code. In each packet, the concatenation of a rate compatible punctured convolutional (RCPC) code and an error detecting parity check (CRC) code is used. Across the packets, Reed-Solomon codes are used. These steps provide the robust source coder with additional layers of protection against channel noise. Finally, in the decoder side, an error concealment function is performed for the lost blocks. Simulations show that the multilayered protection of 3-D SPIHT outperforms the methods that use single layer protection in terms of average PSNRs and the PSNR ranges, and provides higher average PSNR's and lower PSNR variances. (C) 2004 Elsevier Inc. All rights reserved.

关键词： video compression video transmission robust source coding error resilient transmission joint source and channel coding 3-D wavelet transform embedded wavelet coding

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Optimal filter banks for multiple description coding: Analysis and synthesis

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IEEE TRANSACTIONS ON INFORMATION THEORY 2002年第7期48卷 2036-2052页

作者： Dragotti, PL Servetto, SD Vetterli, M Swiss Fed Inst Technol LCAV EPFL CH-1015 Lausanne Switzerland

Multiple description (MD) coding is a source coding technique for information transmission over unreliable networks. In MD coding, the coder generates several different descriptions of the same signal and the decoder can produce a useful reconstruction of the source with any received subset of these descriptions. In this paper, we study the problem of MD coding of stationary Gaussian sources with memory. First, we compute an approximate MD rate distortion region for these sources, which we prove to be asymptotically tight at high rates. This region generalizes the MD rate distortion region of El Gamal, Cover, and Ozarow for memoryless Gaussian sources. Then, we develop an algorithm for the design of optimal two-channel biorthogonal filter banks for MD coding of Gaussian sources. We show that optimal filters are obtained by allocating the redundancy over frequency with a reverse "water-filling" strategy. Finally, we present experimental results which show the effectiveness of our filter banks in the low complexity, low rate regime.

关键词： filter bank design integer-to-integer transforms multiple description (MD) coding rate distortion functions robust source coding

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Full-featured, error-resilient, scalable wavelet video codec based on the set partitioning in hierarchical trees (SPIHT) algorithm

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2002年第3期12卷 157-171页

作者： Cho, S Pearlman, WA Rensselaer Polytech Inst Ctr Next Generat Video Res Dept Elect Comp & Syst Engn Troy NY 12180 USA Rensselaer Polytech Inst Ctr Image Proc Res Troy NY 12180 USA

Compressed video bitstreams require protection from channel errors in a wireless channel. The 3-D set partitioning in hierarchical trees (SPIHT) coder has proved its efficiency and its real-time capability in compression of video. A forward-error-correcting (FEC) channel (RCPC) code combined with a single automatic-repeat request (ARQ) proved to be an effective means for protecting the bitstream. There were two problems with this scheme: 1) the noiseless reverse channel ARQ may not be feasible in practice and 2) in the absence of channel coding and ARQ, the decoded sequence was hopelessly corrupted even for relatively clean channels. In this paper, we eliminate the need for ARQ by making the 3-D SPIHT bitstream more robust and resistant to channel errors. We first break the wavelet transform into a number of spatio-temporal tree blocks which can be encoded and decoded independently by the 3-D SPIHT algorithm. This procedure brings the added benefit of parallelization of the compression and decompression algorithms, and enables implementation of region-based coding. We demonstrate the packetization of the bitstream and the reorganization of these packets to achieve scalability in bit rate and/or resolution in addition to robustness. Then we encode each packet with a channel code. Not only does this protect the integrity of the packets in most cases, but it also allows detection of packet-decoding failures, so that only the cleanly recovered packets are reconstructed. In extensive comparative tests, the reconstructed video is shown to be superior to that of MPEG-2, with the margin of superiority growing substantially as the channel becomes noisier. Furthermore, the parallelization makes possible real-time implementation in hardware and software.

关键词： 3-D wavelet transform combined source-channel coding embedded wavelet coding error-resilient transmission robust source coding video compression video transmission

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Error resilient compression and transmission of scalable video

Error resilient compression and transmission of scalable vid...

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Conference on Applications of Digital Image Processing XXIII

作者： Cho, S Pearlman, WA Rensselaer Polytech Inst Dept Elect Comp & Syst Engn Ctr Digital Video & Media Res Troy NY 12180 USA

ISBN: (纸本)0819437603

Compressed video bitstreams require protection from channel errors in a wireless channel and protection from packet loss in a wired ATM channel. The three-dimensional (3-D) SPIHT coder has proved its efficiency and its real-time capability in compression of video. A forward-error-correcting(FEC) channel (RCPC) code(1) combined with a single ARQ (automatic-repeat-request) proved to be an effective means for protecting the bitstream. There were two problems with this scheme: the noiseless reverse channel ARQ may not be feasible in practice;and, in the absence of channel coding and ARQ, the decoded sequence was hopelessly corrupted even for relatively clean channels. In this paper, we first show how to make the 3-D SPIHT bitstream more robust to channel errors by breaking the wavelet transform into a number of spatio-temporal tree blocks which can be encoded and decoded independently. This procedure brings the added benefit of parallelization of the compression and decompression algorithms. Then we demonstrate the packetization of the bit stream and the reorganization of these packets to achieve scalability in bit rate and/or resolution in addition to robustness. Then we encode each packet with a channel code. Not only does this protect the integrity of the packets in most cases, but it also allows detection of packet decoding failures, so that only the cleanly recovered packets are reconstructed. This procedure obviates ARQ, because the performance is only about 1 dB worse than normal 3-D SPIHT with FEC and ARQ. Furthermore, the parallelization makes possible real-time implementation in hardware and software.

关键词： video compression video transmission robust source coding error resilient transmission combined source-channel coding 3-D wavelet transform embedded wavelet coding

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Look-ahead predictive trellis-coded quantization with nonlinear filters for image transmission over tactical channels

Look-ahead predictive trellis-coded quantization with nonlin...

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1997 Conference on Visual Communications and Image Processing

作者： Marvel, LM Boncelet, CG Army Research Lab. (United States) Univ. of Delaware (United States)

ISBN: (纸本)0819424358

Many battlefield applications require the ability to transmit images over narrow bandwidth noisy channels. Previous research has demonstrated that the utilization of Predictive Trellis-Coded Quantization (PTCQ) incorporating a nonlinear prediction filter results in a method of robust source coding. robust source coding provides both compression and noise mitigation without the need to allocate additional bandwidth for channel coding. However, the traditional PTCQ algorithm is suboptimal. This suboptimality arises from the prediction operation;a trellis path is eliminated in favor of the survivor path at each stage in time to form the input to the prediction filter. It is reasonable to assume that this eliminated path may have produced a lower overall distortion than the survivor path. In this paper we address this suboptimality by incorporating a look-ahead stage into PTCQ algorithm. This ''less-greedy'' approach allows coding gains with a slight increase in overhead. The resulting algorithm yields an image encoding technique, which enables resilient image transmission over tactical channels.

关键词： robust source coding image compression noise mitigation nonlinear filters PTCQ

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Scalable multiple description coding of video using motion compensated temporal filtering and embedded multiple description scalar quantization

Scalable multiple description coding of video using motion c...

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Conference on Wavelet Applications in Industrial Processing II

作者： Verdicchio, F Munteanu, A Gavrilescu, A Cornelis, J Schelkens, P Free Univ Brussels Interdisciplinary Inst Broadband Technol IBBT Dept Elect & Informat Proc ETRO B-1050 Brussels Belgium

ISBN: (纸本)0819455601

Real time delivery of video over best-effort and error-prone networks requires compression systems that dynamically adapt the rate to the available channel capacity and exhibit robustness to loss of some data as retransmission is often impractical. Error resiliency, however, significantly lowers the coding performance when rigid design is performed based on a worst-case scenario. This paper presents a scalable video coding scheme that couples the compression efficiency of the open-loop architecture with the robustness of multiple description source coding. The use of embedded multiple description quantization and a novel channel-aware rate-allocation allows for shaping on-the fly the output bit-rate and the degree of resiliency without resorting to channel coding. As a result, robustness to data losses is traded for better visual quality when transmission occurs over reliable channels, while error resilience is introduced when noisy links are involved. The advantage of our proposal is demonstrated in the context of packet-lossy networks comparing the performance of similar instantiations of the video codec employing non-scalable redundancy.

关键词： robust source coding multiple description coding error resilience scalable video coding

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Approach to the joint optimization of video communications and video signal processing

Approach to the joint optimization of video communications a...

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Conference on Advanced Signal Processing Algorithms, Architectures, and Implementations XI

作者： Pearlman, WA Medley, MJ Suter, BW Rensselaer Polytech Inst Ctr Next Generat Video Res Troy NY 12180 USA

ISBN: (纸本)0819441880

Compressed video bitstreams require protection from channel errors in a wireless channel. The three-dimensional (3-D) SPIHT coder has proved its efficiency and its real-time capability in compression of video. A forward-error-correcting (FEC) channel (RCPC) code combined with a single ARQ (automatic-repeat-request) proved to be an effective means for protecting the bitstream. In this paper, the need for ARQ is eliminated by making the 3-D SPIHT bitstream more robust and resistant to channel errors. Packetization of the bitstream and the reorganization of these packets to achieve scalability in bit rate and/or resolution in addition to robustness is demonstrated and combined with channel coding to not only protect the integrity of the packets, but also allow detection of packet decoding failures, so that only the cleanly recovered packets are reconstructed. In extensive comparative tests, the reconstructed video is shown to be superior to that of MPEG-2, with the margin of superiority growing substantially as the channel becomes noisier.

关键词： video compression video transmission robust source coding error resilient transmission combined source-channel coding 3-D wavelet transform embedded wavelet coding

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