检索结果-内蒙古大学图书馆

IEEE International Conference on Image Processing (ICIP 2007)

作者： Baccichet, Pierpaolo Rane, Shantanu Chimienti, Antonio Girod, Bernd Max Planck Ctr Visual Comp & Commun Stanford CA 94305 USA Stanford Univ Informat Syst Lab Stanford CA 94305 USA IEIIT Natl Res Council Turin Italy

ISBN: (纸本)9781424414369

This paper proposes a scheme for low-delay robust transmission of video signals over packet erasure channels. In applications such as video conferencing, the permissible delay between encoding and playback may be too low to allow retransmission or channel coding approaches which require buffering several video packets. For such a scenario, we present a scheme that provides error robustness using redundant video descriptions applied to pertinent portions of the video signal. In the H.264/AVC specification, this can be efficiently implemented using redundant slices and Flexible Macroblock Ordering (FMO). We describe a model that determines the bit rate of the redundant descriptions such that the expected distortion at the decoder is minimized. Across all the video test sequences used, the average video quality delivered by the proposed scheme is 3.7 dB higher than decoder-based error concealment, and 1.2 dB higher than encoder-based loss-aware rate-distortion optimization.

关键词： error-resilient video coding H.264/AVC flexible macroblock ordering redundant slices

来源：评论

学校读者我要写书评

暂无评论

Analysis of IEEE 802.11N-like transmission techniques with and without prior CSI for video applications

Analysis of IEEE 802.11N-like transmission techniques with a...

引用

IEEE International Conference on Image Processing (ICIP 2007)

作者： Tesanovic, Milos Bull, David Doufexi, Angela Nix, Andrew Univ Bristol Bristol BS8 1TH Avon England

ISBN: (纸本)9781424414369

Previous research into MIMO systems has focused little on optimisation for video transmission. In terms of multimedia transmission, spatial multiplexing (SM) is commonly proposed as the most suitable MIMO technique. Most SM-based video transport schemes look to exploit the multiplexing gain, which comes at the expense of a relatively high SNR, unless the channel state is known at the transmitter. Space-time block coding (STBC) is an attractive technique that does not provide the mapping flexibility of SM techniques, but does dramatically reduce the packet-error rate. This paper compares these techniques in terms of decoded video quality through simulations based on practical transmission scenarios. The use of multiple-description coding (MDC) is further proposed to provide a new class of wireless video transmission algorithms.

关键词： multimedia communication MIMO systems error-resilient video coding multiple-description coding (MDC) video mapping

来源：评论

学校读者我要写书评

暂无评论

error-resilient video coding using long-term memory prediction and feedback channel

引用

SIGNAL PROCESSING-IMAGE COMMUNICATION 2002年第8期17卷 597-609页

作者： Jung, HS Kim, RC Lee, SU Seoul Natl Univ Sch Elect Engn & Comp Sci Inst New Media & Comm Gwanak Gu Seoul 151742 South Korea Seoul Natl Univ Dept Elect & Comp Engn Seoul South Korea

The MC-DCT-based video coding has been generally used for its efficiency and easy implementation, but it is very vulnerable in error-prone environments. In this paper, we address an error-resilient video coding using multiple reference frame, based on the long-term memory motion compensated prediction (LTMP) (IEEE Trans. Circuits Syst. video Technol. 9 (1) (1999) 70), and an error concealment technique associated with the proposed technique. The rate-distortion optimization of T. Wiegand et al. (1999) is modified by adding dispersion measure of the temporal motion vectors in order to provide the error-resiliency and much improved error concealment performance. Also, the proposed algorithm confines the temporal error propagation using negative acknowledgement in feedback channel, in which both the corrupted area by channel errors and the error-propagated area are estimated and removed from the search region for the motion compensation. Thus, the proposed algorithm yields the similar performance to the forced intra update (FIU) in terms of the PSNR, but avoids the abrupt increase in the bitrate, resulting in more efficient network utilization than the FIU. By the computer simulations, we shall demonstrate that the proposed technique provides an acceptable performance both subjectively and objectively in error-prone environments, as compared with H.263 and LTMP, with or without the feedback messages. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： error-resilient video coding multiple reference frame long-term memory prediction error concealment feedback channel dispersion measure of the temporal motion vectors

来源：评论

学校读者我要写书评

暂无评论

H.264-based multiple description video coder and its DSP implementation

H.264-based multiple description video coder and its DSP imp...

引用

IEEE International Conference on Image Processing (ICIP 2006)

作者： Wei, Zhe Cai, Canhui Ma, Kai-Kuang Huaqiao Univ Inst Informat Sci & Engn Quanzhou 362021 Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

ISBN: (纸本)9781424404810

In this paper, a novel H.264-based multiple description coding (MDC) framework, called the prediction-based spatial polyphase transform (PSPT) multiple description video coding, is introduced to enhance the error-resilience ability and reduce the computational complexity of the H.264 codec. The proposed PSPT-MDC down-samples each input frame in both the horizontal and the vertical directions, forming four subframes. Instead of directly coding and transporting all the four subframes, two of them are predicted from the other two subframes. The proposed H.264-based PSPT-MDC video codec is then implemented on the TI TMS320C6416 digital signal processor with some optimizations to demonstrate its feasibility and attractive performance, in terms of the decoded video quality and error-resilience capability.

关键词： h.264 multiple description coding error-resilient video coding digital signal processor codec cache memory

来源：评论

学校读者我要写书评

暂无评论

Systematic lossy error protection of video based on H.264/AVC redundant slices

Systematic lossy error protection of video based on H.264/AV...

引用

Conferenceon Visual Communications and Image Processing 2006

作者： Rane, S Girod, B Stanford Univ Informat Syst Lab Stanford CA 94305 USA

ISBN: (纸本)0819461172

We propose the use of H.264 redundant slices for Systematic Lossy error Protection (SLEP) of a video signal transmitted over an error-prone channel. In SLEP, the video signal is transmitted to the decoder without channel coding. Additionally, a Wyner-Ziv encoded version of the video signal is transmitted in order to provide error-resilience. In the event of channel errors, the Wyner-Ziv description is decoded as a substitute for the error-prone portions of the primary video signal. Since the Wyner-Ziv description is typically coarser than the primary video signal, SLEP is a lossy error protection technique which trades-off residual quantization distortion for improved error-resilience properties, such as graceful degradation of decoder picture quality. We describe how H.264 redundant slices can be used to generate the Wyner-Ziv description, and present simulation results to demonstrate the advantages of this method over traditional methods such as FEC.

关键词： systematic lossy source-channel coding systematic lossy error protection Wyner-Ziv coding Slepian-Wolf coding side information redundant slices error-resilient video coding distributed video coding

来源：评论

学校读者我要写书评

暂无评论

Enhanced error-resilient video Transport over MIMO Systems using Multiple Descriptions

Enhanced Error-Resilient Video Transport over MIMO Systems u...

引用

64th IEEE Vehicular Technology Conference

作者： Tesanovic, Milos Bull, David R. Doufexi, Angela Univ Bristol Ctr Commun Res Bristol BS8 1TH Avon England

ISBN: (纸本)9781424400621

Much of the work on wireless transmission over the past several years has focused on simulation and deployment of multiple-input-multiple-output (MIMO) systems. These systems provide benefits of improved robustness and enhanced throughput at relatively low cost. Despite the increased understanding of the performance of MIMO systems, little is known about which combination of channel and source coding yields the best results for video transport. It is clear that new ways of providing error-resilience that emerge from MIMO architectures need to be developed which can cope with the particularities of video content. This paper proposes a new scheme for video transmission using multiple-description coding (MDC). Two complementary MIMO techniques, space-time block coding (STBC) and spatial multiplexing (SM), are employed. The quality of the reconstructed video, already enhanced by the inherent MIMO systems' properties, is further improved through the use of MDC.

关键词： multiple-description coding (MDC) error-resilient video coding MIMO systems space-time processing spatial multiplexing video mapping singular value decomposition

来源：评论

学校读者我要写书评

暂无评论

Towards robust AV conferencing on next-generation networks

Towards robust AV conferencing on next-generation networks

引用

Conference on Multimedia Computing and Networking 2005

作者： Liu, HN Cheng, L El Zarki, M Univ Calif Irvine Sch Informat & Comp Sci Irvine CA 92697 USA

ISBN: (纸本)0819456535

In order to enable a truly pervasive computing environment, next generation networks (including B3G and 4G) will merge the broadband wireless and wireline networking infrastructure. However, due to the tremendous complexity in administration and the unreliability of the wireless channel, provision of hard-guarantees for services on such networks will not happen in the foreseeable future. This consequently makes it particularly challenging to offer viable AV conferencing services due to their stringent synchronization, delay and data fidelity requirements. We propose in this paper a robust application-level solution for wireless mobile AV conferencing on B3G/4G networks. Expecting no special treatment from the network, we apply a novel adaptive delay and synchronization control mechanism to maintain the synchronization and reduce the latency as much as possible. We also employ a robust video coding technique that has better error-resilience capability. We investigate the performance of the proposed solution through simulations using a three-state hidden Markov chain as the generic end-to-end transport channel model. The results show that our scheme yields tight synchronization performance, relatively low end-to-end latency and satisfactory presentation quality. The scheme successfully provides a fairly robust AV conferencing service.

关键词： B3G/4G networks AV conferencing adaptive delay and synchronization control error-resilient video coding

来源：评论

学校读者我要写书评

暂无评论

Network-adaptive video communication using packet path diversity and rate-distortion optimized reference picture selection

Network-adaptive video communication using packet path diver...

引用

5th IEEE Workshop on Multimedia Signal Processing (MMSP 2002)

作者： Liang, YJ Setton, E Girod, B Stanford Univ Dept Elect Engn Informat Syst Lab Stanford CA 94305 USA

In this paper, we present error-resilient Internet video transmission using path diversity and rate-distortion optimized reference picture selection. Under this scheme, the optimal packet dependency is determined adapting to network characteristics and video content, to achieve a better trade-off between coding efficiency and forming independent streams to increase error-resilience. The optimization is achieved within a rate-distortion framework, so that the expected end-to-end distortion is minimized under the given rate constraint. The expected distortion is calculated based on an accurate binary tree modeling with the effects of channel loss and error concealment taken into account. With the aid of active probing, packets are sent across multiple available paths according to a transmission policy which takes advantage of path diversity and seeks to minimize the loss rate. Experiments demonstrate that the proposed scheme provides significant diversity gain, as well as gains over video redundancy coding and the NACK mode of conventional reference picture selection.

关键词： Path diversity network-adaptive video coding error-resilient video coding source-channel coding reference picture selection low-latency rate-distortion optimization video streaming

来源：评论

学校读者我要写书评

暂无评论

An enhanced two-stage multiple description video coder with drift reduction

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 2004年第1期14卷 122-127页

作者： Lee, YC Altunbasak, Y Mersereau, RM Georgia Inst Technol Sch Elect & Comp Engn Ctr Signal & Image Proc Atlanta GA 30332 USA

Multiple description coding (MDC) is a source coding technique that exploits path diversity to increase the robustness of transmitting a compressed signal over error-prone channels. However, the application of MDC to video coding is still problematic because a prediction mismatch problem, called drift, may occur at the decoder when one description is lost. In the literature, it has been shown that drift can be effectively prevented by encoding this prediction mismatch and sending it as side information in a three-prediction-loop structure. However, this side information is totally redundant when both descriptions are received. In this paper, we propose a very simple, but efficient two-stage MDC in the central prediction loop based on Reibman's three-prediction-loop structure. In our design, an additional multiple description scalar quantizer is introduced into the central prediction loop. The encoding of the side information is modified in such a way that it can be used to improve the video quality when no drift occurs, but All maintain drift prevention capability. The simulation results with different video sequences at various packet loss rates demonstrate that the proposed two-stage MDC structure indeed enhances the quality when the channel is error-free, yet effectively avoids drift when one description is completely lost.

关键词： drift problem error-resilient video coding motion-compensated multiple description prediction multiple description coding (MDC) multiple description scalar quantization (MDSQ) video streaming

来源：评论

学校读者我要写书评

暂无评论

Rate distortion optimized coding mode selection for H.264/AVC in wireless environments

引用

IEICE TRANSACTIONS ON COMMUNICATIONS 2004年第7期E87B卷 2057-2060页

作者： Zhang, W Zhou, YH Shanghai Jiao Tong Univ Inst Image Commun & Informat Proc Shanghai 200030 Peoples R China

A flexible and robust rate-distortion optimization algorithm is presented to select macroblock coding mode for H.264/AVC transmission over wireless channels subject to burst errors. A two-state Markov model is used to describe the burst errors on the packet level. With the feedback information from the receiver and the estimation of the channel errors, the algorithm analyzes the distortion of the reconstructed macroblock at the decoder due to the channel errors and spatial and temporal error propagation. The optimal coding mode is chosen for each macroblock in rate-distortion (R-D)-based framework. Experimental results using the H.264/AVC test model show a significant performance of resilience to the burst errors.

关键词： coding mode error-resilient video coding H.264/AVC rate-distortion optimization wireless video transmission

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：