检索结果-内蒙古大学图书馆

Can Gray Code Improve the Performance of distributed video coding?

IEEE ACCESS 2016年第99期4卷 4431-4441页

作者： Song, Juan Shen, Peiyi Wang, Keyan Zhang, Liang Song, Houbing Xidian Univ Natl Sch Software Xian 710071 Peoples R China Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Peoples R China West Virginia Univ Dept Elect & Comp Engn Montgomery WV 25136 USA

Gray code application in distributed video coding (DVC) has been studied in the literature and it was claimed that DVC performance could be improved by Gray code because of stronger bitplane correlation presented. However, two factors are ignored in the literature, which renders the aforementioned claim untenable. These factors are log-likelihood ratio (LLR) computation and robustness to wrongly decoded bits, which may influence the DVC performance when different bit representations are used. This paper comprehensively evaluates the performances of Gray code in different DVC schemes, such as feedback channel-based transform domain Wyner-Ziv (FC_TDWZ) video coding, parallel pixel domain Wyner-Ziv video coding, and encoder rate control-based TDWZ (ERC_TDWZ). Experimental results suggest that the Gray code does not always improve the DVC performance, although stronger bitplane correlation is presented. In particular, the performance of FC_TDWZ with Gray code is exactly the same as that with natural bit code, because the same magnitudes of LLRs are obtained. Moreover, the reconstruction quality of the WZ frames in ERC_TDWZ is improved by Gray code not because of stronger bitplane correlation but because Gray code is more robust to wrongly decoded bits induced by rate underestimation. However, these RD gains are quite limited when the rate is controlled accurately at the encoder.

关键词： distributed video coding Gray code performance evaluation log-likelihood ratios robustness to wrongly decoded bits

来源：评论

学校读者我要写书评

暂无评论

Improved side information generation algorithm based on naive Bayesian theory for distributed video coding

引用

IET IMAGE PROCESSING 2018年第3期12卷 354-360页

作者： Cao, Ying Sun, Lijuan Han, Chong Guo, Jian Nanjing Univ Posts & Telecommun Coll Comp Nanjing 210003 Peoples R China Nanjing Univ Posts & Telecommun Jiangsu High Technol Res Key Lab Wireless Sensor Nanjing 210003 Peoples R China

In Wyner-Ziv (WZ) video coding, side information (SI), which is a decoder estimation of the original frame, plays a key role in overall compression performance. Many researchers have focused on SI in the past decade to develop efficient SI generation algorithms. In this study, the authors propose an algorithm combined with naive Bayesian theory to create a generic model that can complete the generation of SI in the WZ video coding framework. The proposed scheme first utilises samples to build the initial model, after which the algorithm filters the samples and models according to the threshold T-1. Then, the algorithm takes the filtered samples and models as conditions to build the generic model. Finally, the proposed scheme completes the generation of SI with the motion vectors obtained from the generated model. Experimental results show that the proposed algorithm achieves better rate-distortion performance and improves peak signal-to-noise ratio by up to 0.5 and 2 dB compared with state-of-the-art techniques.

关键词： video coding Bayes methods decoding image motion analysis improved side information generation algorithm naive Bayesian theory distributed video coding Wyner-Ziv video coding decoder estimation SI creation algorithms WZ video coding framework motion vectors rate-distortion performance peak signal-to-noise ratio

来源：评论

学校读者我要写书评

暂无评论

A Symbol Based distributed video coding System Using Multiple Hypotheses

引用

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2014年第2期E97A卷 632-641页

作者： Louw, Daniel Johannes Kaneko, Haruhiko Tokyo Inst Technol Tokyo 1528552 Japan

Single view distributed video coding (DVC) is a coding method that allows for the computational complexity of the system to be shifted from the encoder to the decoder. This property promotes the use of DVC in systems where processing power or energy use at the encoder is constrained. Examples include wireless devices and surveillance. This paper proposes a multi-hypothesis transform domain single-view DVC system that performs symbol level coding with a non-binary low-density parity-check code. The main contributions of the system relate to the methods used for combining multiple side information hypotheses at the decoder. The system also combines interpolation and extrapolation in the side information creation process to improve the performance of the system over larger group-of-picture sizes.

关键词： distributed video coding non-binary LDPC side information multi-hypothesis

来源：评论

学校读者我要写书评

暂无评论

Successive refinement of side information frames in distributed video coding

引用

MULTIMEDIA TOOLS AND APPLICATIONS 2019年第15期78卷 20697-20722页

作者： Taheri, Yaser Mohammad Ahmad, M. Omair Swamy, M. N. S. Concordia Univ Dept Elect & Comp Engn Montreal PQ H3G 1M8 Canada

In distributed video coding, generation of high-quality side information is required for reliable soft-input information for decoding each DCT band of a Wyner-Ziv (WZ) frame in the decoder, which in turn leads to a more efficient decoding. Consequently, less error-correcting bits need to be transmitted from the encoder to the decoder to decode the bitplanes of each DCT band, leading to a better compression efficiency and rate-distortion performance. In this paper, we investigate the problem of successive improvements in the quality of side information frames in distributed video coding in order to improve the rate-distortion performance. A new algorithm for the successive refinement of the side information is proposed to refine the initial side information frame using the additional information obtained after decoding the previous DCT bands of a WZ frame. As more information about the WZ frame becomes available after the decoding of each DCT band of the WZ frame, the corresponding side information frame is refined and then employed to decode the next DCT band of the WZ frame. Simulations are carried out demonstrating that the proposed algorithm for refinement of side information frame results in a considerable improvement in the RD performance of distributed video coding.

关键词： distributed video coding Wyner-Ziv frame Side information refinement

来源：评论

学校读者我要写书评

暂无评论

Evaluation of Side Information Effectiveness in distributed video coding

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 2013年第12期23卷 2116-2126页

作者： Maugey, Thomas Gauthier, Jerome Cagnazzo, Marco Pesquet-Popescu, Beatrice Swiss Fed Inst Technol CH-1015 Lausanne Switzerland French Alternat Energies & Atom Energy Commiss CE Gif Sur Yvette France TELECOM ParisTech Inst Mines TELECOM F-75014 Paris France

The rate-distortion performance of a distributed video coding system strongly depends on the characteristics of the side information. One could naively think that the best side information is the one with the largest PSNR with respect to the original corresponding image. However, previous works have shown that this is not always the case and a reduction of the side information MSE does not always translate into better rate-distortion performance for the complete system. The scope of this paper is to explore a set of metrics other than the PSNR and explicitly designed to classify the side information with respect to its impact on the end-to-end compression performance. A first contribution is to define an experimental framework that can be used to meaningfully compare different metrics for side information evaluation. As a second contribution, our analysis allows to understand why in some cases PSNR-based metrics provide a fairly reliable estimation of the side information quality, while in other cases they do not. This analysis also allows us to introduce a set of new metrics that are better adapted for side information effectiveness evaluation, and that are based on a suitable power of the absolute difference between side information and the original image, or on the Hamming distance between the respective transform coefficients. Besides their theoretical interest, these new metrics can also improve the rate-distortion performance of some distributed video coding systems such as the hash-based ones. We observe improvement up to 74 % rate reduction in a simple study case.

关键词： distributed video coding quality evaluation side information

来源：评论

学校读者我要写书评

暂无评论

Performance evaluation of wavelet-based distributed video coding schemes

引用

SIGNAL IMAGE AND video PROCESSING 2011年第1期5卷 49-60页

作者： Bernardini, Riccardo Rinaldo, Roberto Vitali, Andrea Zontone, Pamela Univ Udine Dipartimento Ingn Elettr Gest & Meccan I-33100 Udine Italy ST Microelect I-20041 Agrate Brianza Italy

In this paper we propose and compare different distributed video coding (DVC) schemes based on the use of the wavelet transform, which naturally allows for spatial and other forms of scalability. In particular, we propose a hybrid encoder which utilizes channel codes, and evaluate its performance in the absence of a feedback channel. The proposed scheme uses statistical models for the estimation of the required bitrate at the encoder. We also propose a scheme that is based on a modulo reduction procedure and does not use channel codes at the receiver/transmitter. These schemes are compared with more conventional coders that do not or only partially exploit the distributed coding paradigm. Experimental results show that the considered schemes have good performance when compared with similar asymmetric video compression schemes, and that DVC can be an interesting option in appropriate scenarios.

关键词： distributed video coding Error correcting codes Wavelet transform Modulo reduction

来源：评论

学校读者我要写书评

暂无评论

Adaptive coset partition for distributed video coding

引用

SIGNAL PROCESSING 2010年第8期90卷 2480-2486页

作者： Zhang, Yixuan Zhu, Ce Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

distributed video coding (DVC) can enable video coding systems to shift motion search complexity from the encoder to the decoder, for which one of the practical constructive frameworks is using coset partition. Two typical coset partition methods, namely, modular based coset partition and scalar quantizer based coset partition, are considered and examined. Taking advantage of their respective strengths while circumventing their weaknesses, an adaptive coset partition scheme is proposed by integrating the two coset partition methods to minimize the decoding errors, where a mode design for bit allocation between the two schemes is developed based on prediction of the correlation noise. Experimental results validate effectiveness of the proposed scheme with better coding performance as compared with the relevant coset partition algorithms. (C) 2010 Elsevier B.V. All rights reserved.

关键词： distributed video coding Coset partition Wyner-Ziv coding Bit allocation

来源：评论

学校读者我要写书评

暂无评论

CDV-DVC: Transform-domain distributed video coding with multiple channel division

引用

JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2013年第5期24卷 534-543页

作者： Park, Sang-Uk Lee, Young-Yoon Kim, Chang-Su Lee, Sang-Uk Seoul Natl Univ Sch Elect Engn Seoul South Korea Seoul Natl Univ INMC Seoul South Korea Samsung Elect Co Ltd Multimedia Platform Lab Suwon South Korea Korea Univ Sch Elect Engn Seoul South Korea

This paper proposes an efficient distributed coding system based on multiple channel division. We develop the hierarchical motion refinement scheme using DC syndrome bits to generate high quality side information (SI) for Wyner-Ziv (WZ) frames. Moreover, we estimate local distortion characteristics of an SI frame and encode the SI frame in three coding modes: skip mode for the reliable channel, WZ mode for the medium channel, and intra mode for the unreliable channel. No bit is transmitted in the skip mode. Syndrome bits in the WZ mode are adaptively allocated based on the local distortion characteristics. The H.264 intra coding is performed in the intra mode to recover severely erroneous blocks. Experimental results show that the proposed algorithm provides significantly better rate-distortion performance than the state-of-the-art DISCOVER codec. (C) 2013 Elsevier Inc. All rights reserved.

关键词： distributed video coding Wyner-Ziv coding Side information generation Motion-compensated frame interpolation Channel division Hierarchical motion estimation Key frame-based estimate Syndrome-based estimate

来源：评论

学校读者我要写书评

暂无评论

Fusion of Global and Local Motion Estimation for distributed video coding

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 2013年第1期23卷 158-172页

作者： Abou-Elailah, Abdalbassir Dufaux, Frederic Farah, Joumana Cagnazzo, Marco Pesquet-Popescu, Beatrice TELECOM Paristech Inst Telecom Signal & Image Proc Dept F-75634 Paris France Holy Spirit Univ Kaslik Fac Engn Dept Telecommun Engn Jounieh Lebanon

The quality of side information plays a key role in distributed video coding. In this paper, we propose a new approach that consists of combining global and local motion compensation at the decoder side. The parameters of the global motion are estimated at the encoder using scale invariant feature transform features. Those estimated parameters are sent to the decoder in order to generate a globally motion compensated side information. Conversely, a locally motion compensated side information is generated at the decoder based on motion-compensated temporal interpolation of neighboring reference frames. Moreover, an improved fusion of global and local side information during the decoding process is achieved using the partially decoded Wyner-Ziv frame and decoded reference frames. The proposed technique improves significantly the quality of the side information, especially for sequences containing high global motion. Experimental results show that, as far as the rate-distortion performance is concerned, the proposed approach can achieve a PSNR improvement of up to 1.9 dB for a Group of Pictures (GOP) size of 2, and up to 4.65 dB for larger GOP sizes, with respect to the reference DISCOVER codec.

关键词： distributed video coding global motion local motion rate-distortion performance side information refinement Wyner-Ziv coding

来源：评论

学校读者我要写书评

暂无评论

Perceptual-based distributed video coding

引用

JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2012年第3期23卷 535-548页

作者： Sun, Yu-Chen Tsai, Chun-Jen Natl Chiao Tung Univ Dept Comp Sci Hsinchu 30010 Taiwan

In this paper, we propose a perceptual-based distributed video coding (DVC) technique. Unlike traditional video codecs, DVC applies video prediction process at the decoder side using previously received frames. The predicted video frames (i.e., side information) contain prediction errors. The encoder then transmits error-correcting parity bits to the decoder to reconstruct the video frames from side information. However, channel codes based on i.i.d. noise models are not always efficient in correcting video prediction errors. In addition, some of the prediction errors do not cause perceptible visual distortions. From perceptual coding point of view, there is no need to correct such errors. This paper proposes a scheme for the decoder to perform perceptual quality analysis on the predicted side information. The decoder only requests parity bits to correct visually sensitive errors. More importantly, with the proposed technique, key frames can be encoded at higher rates while still maintaining consistent visual quality across the video sequence. As a result, even the objective PSNR measure of the decoded video sequence will increase too. Experimental results show that the proposed technique improves the R-D performance of a transform domain DVC codec both subjectively and objectively. Comparisons with a well-known DVC codec show that the proposed perceptual-based DVC coding scheme is very promising for distributed video coding framework. (C) 2012 Elsevier Inc. All rights reserved.

关键词： distributed video coding Perceptual-based coding Wyner-Ziv coding Region-of-interest analysis Motion consistency analysis Texture consistency analysis Visual distortion estimation Side-information error classification

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：