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Design of a Non-linear Quantizer for Transform Domain DVC

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2009年第3期E92A卷 847-852页

作者： Badem, Murat B. Weerakkody, Rajitha Fernando, Anil Kondoz, Ahmet M. Univ Surrey Ctr Commun Syst Res Guildford GU2 7XH Surrey England

distributed video coding (DVC) is an emerging video coding paradigm that is characterized by a flexible architecture for designing very low cost video encoders. This feature could be very effectively utilized in a number of potential many-to-one type video coding applications. However, the compression efficiency of the latest DVC implementations still falls behind the state-of-the-art in conventional video coding technologies, namely H.264/AVC. In this paper, a novel non-linear quantization algorithm is proposed for DVC in order to improve the rate-distortion (RD) performance. The proposed solution is expected to exploit the dominant contribution to the picture quality front the relatively small coefficients when the high concentration of the coefficients near zero as evident when the residual input video signal for the Wyner-Ziv frames is considered in the transform domain. The performance of the proposed solution incorporating the non-linear quatizer is compared with the performance of all existing transform domain DVC solution that uses a linear quantizer. The simulation results show a consistently improved RD performance at all bitrates when different test video sequences with varying motion levels are considered.

关键词： Wyner-Ziv coding non-linear quantizer distributed video coding

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SIFT-Based Homographies for Efficient Multiview distributed Visual Sensing

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IEEE SENSORS JOURNAL 2015年第5期15卷 2643-2656页

作者： Dias, Andre Seixas Brites, Catarina Ascenso, Joao Pereira, Fernando Univ Lisbon Inst Super Tecn Inst Telecomun P-1049001 Lisbon Portugal

Considering the scarce resources in visual sensor networks, video coding solutions are necessary to address these constraints, namely the limited energy, memory, and bandwidth. The distributed video coding (DVC) paradigm is able to address these limitations by shifting most of the complexity to the decoder, typically a central location with a significant amount of resources. In a DVC context, the video codec rate-distortion (RD) performance is strongly dependent on the efficient generation of the so-called side information (SI). While in monoview DVC solutions the SI is generated by exploiting only the temporal correlation between frames, in multiview DVC (MV-DVC) solutions, the SI may be estimated by exploiting both the temporal and interview correlations. In this paper, a novel MV-DVC solution is proposed to improve the state-of-the-art MV-DVC RD performance with two key contributions in terms of an interview SI creation and SI fusion. According to the obtained experimental results, the proposed solution improves the RD performance associated to the current MV-DVC state-of-the-art solutions, exhibiting bitrate savings similar to 10% for the same output video quality, without increasing the encoding complexity and eventually also the decoding complexity.

关键词： distributed video coding visual sensors multiview SIFT homography fusion

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Toward enhancing the distributed video coder under a multiview video codec framework

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JOURNAL OF ELECTRONIC IMAGING 2016年第6期25卷 1-20页

作者： Lee, Shih-Chieh Chen, Jiann-Jone Tsai, Yao-Hong Chen, Chin-Hua Natl Taiwan Univ Sci & Technol 43Sect 4Keelung Rd Taipei 106 Taiwan Hsuan Chuang Univ 34 Hsuan Chuang Rd Hsinchu 300 Taiwan

The advance of video coding technology enables multiview video (MVV) or three-dimensional television (3-D TV) display for users with or without glasses. For mobile devices or wireless applications, a distributed video coder (DVC) can be utilized to shift the encoder complexity to decoder under the MVV coding framework, denoted as multiview distributed video coding (MDVC). We proposed to exploit both inter-and intraview video correlations to enhance side information (SI) and improve the MDVC performance: (1) based on the multiview motion estimation (MVME) framework, a categorized block matching prediction with fidelity weights (COMPETE) was proposed to yield a high quality SI frame for better DVC reconstructed images. (2) The block transform coefficient properties, i.e., DCs and ACs, were exploited to design the priority rate control for the turbo code, such that the DVC decoding can be carried out with fewest parity bits. In comparison, the proposed COMPETE method demonstrated lower time complexity, while presenting better reconstructed video quality. Simulations show that the proposed COMPETE can reduce the time complexity of MVME to 1.29 to 2.56 times smaller, as compared to previous hybrid MVME methods, while the image peak signal to noise ratios (PSNRs) of a decoded video can be improved 0.2 to 3.5 dB, as compared to H.264/AVC intracoding. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

关键词： multiview video coding distributed video coding block-matching prediction Wyner-Ziv coder turbo coder side information

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Iterative Side-Information Generation in a Mixed Resolution Wyner-Ziv Framework

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 2009年第10期19卷 1409-1423页

作者： Macchiavello, Bruno Mukherjee, Debargha de Queiroz, Ricardo L. Univ Brasilia Dept Engn Eletr Brasilia DF Brazil Hewlett Packard Labs Palo Alto CA 94304 USA

We propose a mixed resolution framework based on full resolution key frames and spatial-reduction-based Wyner-Ziv coding of intermediate nonreference frames. Improved rate-distortion performance is achieved by enabling better side-information generation at the decoder side and better rate-allocation,at the encoder side. The framework enables reduced encoding complexity by low resolution encoding of the nonreference frames, followed by Wyner-Ziv coding of the Laplacian residue. The quantized transform coefficients of the residual frame are mapped to cosets without the use of a feedback channel. A study to select optimal coding parameters in the creation of the memoryless cosets is made. Furthermore, a correlation estimation mechanism that guides the parameter choice process is proposed. The decoder first decodes the low resolution base layer and then generates a super-resolved side-information frame at full resolution using past and future key frames. Coset decoding is carried using side-information to obtain a higher quality version of the decoded frame. Implementation results are presented for the H.264/AVC codec.

关键词： distributed video coding reversed-complexity scalable video coding side-information generation

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A Wyner-Ziv video Transcoder

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 2010年第2期20卷 189-200页

作者： Peixoto, Eduardo de Queiroz, Ricardo L. Mukherjee, Debargha Univ Brasilia Dept Elect Engn BR-70910900 Brasilia DF Brazil Hewlett Packard Labs Palo Alto CA 94304 USA

Wyner-Ziv (WZ) coding of video utilizes simple encoders and highly complex decoders. A transcoder from a WZ codec to a traditional codec can potentially increase the range of applications for WZ codecs. We present a transcoder scheme from the most popular WZ codec architecture to a differential pulse code modulation/discrete cosine transform codec. As a proof of concept, we implemented this transcoder using a simple pixeldomain WZ codec and the standard H.263+. The transcoder design aims at reducing complexity as a large amount of computation is saved by reusing the motion estimation, calculated at the side information generation process, and the I-frame streams. New approaches are used to generate side information and to map motion vectors for the transcoder. Results are presented to demonstrate the transcoder performance.

关键词： distributed video coding H.263+ transcoder Wyner-Ziv coding

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Wyner-Ziv video coding for wireless lightweight multimedia applications

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EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2012年第1期2012卷 1-20页

作者： Deligiannis, Nikos Verbist, Frederik Iossifides, Athanassios C. Slowack, Jurgen Van de Walle, Rik Schelkens, Peter Munteanu, Adrian Vrije Univ Brussel Dept Elect & Informat B-1050 Brussels Belgium Interdisciplinary Inst Broadband Technol B-9050 Ghent Belgium Alexander Technol Educ Inst Thessaloniki Dept Elect GR-57400 Thessaloniki Greece Univ Ghent ELIS Dept Multimedia Lab B-9050 Ghent Belgium

Wireless video communications promote promising opportunities involving commercial applications on a grand scale as well as highly specialized niche markets. In this regard, the design of efficient video coding systems, meeting such key requirements as low power, mobility and low complexity, is a challenging problem. The solution can be found in fundamental information theoretic results, which gave rise to the distributed video coding (DVC) paradigm, under which lightweight video encoding schemes can be engineered. This article presents a new hash-based DVC architecture incorporating a novel motion-compensated multi-hypothesis prediction technique. The presented method is able to adapt to the regional variations in temporal correlation in a frame. The proposed codec enables scalable Wyner-Ziv video coding and provides state-of-the-art distributed video compression performance. The key novelty of this article is the expansion of the application domain of DVC from conventional video material to medical imaging. Wireless capsule endoscopy in particular, which is essentially wireless video recording in a pill, is proven to be an important application field. The low complexity encoding characteristics, the ability of the novel motion-compensated multi-hypothesis prediction technique to adapt to regional degrees of temporal correlation (which is of crucial importance in the context of endoscopic video content), and the high compression performance make the proposed distributed video codec a strong candidate for future lightweight (medical) imaging applications.

关键词： Wyner-Ziv coding distributed video coding hash-based motion estimation wireless lightweight multimedia applications

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Rate-Constrained Region of Interest coding Using Adaptive Quantization in Transform Domain Wyner-Ziv video coding

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IEEE TRANSACTIONS ON BROADCASTING 2016年第3期62卷 685-699页

作者： Park, Jongbin Jeon, Byeungwoo Korea Elect Technol Inst Smart Media Res Ctr Seoul 121835 South Korea Sungkyunkwan Univ Sch Elect & Elect Engn Digital Media Lab Suwon 440746 South Korea

In this paper, we propose a rate-constrained distributed video coding-based region of interest (ROI) coding scheme. The proposed scheme appropriately determines ROI according to an available bit budget that depends on transmission channel and decoding environment. Its subjective quality is faithfully maintained via adaptive ROI definition of the available resources. Prior knowledge about the ROI is represented in terms of Gaussian mixture weighting function, which in turn determines the ROI according to the number of available bits. An adaptive quantization method is used in the ROI bit allocation. Compared to the existing non-ROI-based schemes, the proposed scheme not only improves the ROI coding performance but also the subjective quality of the entire picture.

关键词： distributed video coding region of interest coding adaptive quantization Gaussian mixture weighting function

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Exploitation of motion non-stationarity at the encoder and decoder of DVC: a review

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MULTIMEDIA TOOLS AND APPLICATIONS 2017年第12期76卷 13703-13738页

作者： Zhao, Xin Liu, Jiwei Hu, Guangda Univ Sci & Technol Beijing Sch Automat Beijing 100083 Peoples R China

As a coding scheme for videos, distributed video coding (DVC) requires the development of motion information. However, motion content is unstable. In this article, we review motion non-stationarity considerations at the DVC encoder and decoder. The encoder focuses on adaptive exploration of the changes of interframe spatial-temporal correlation as the criterion for coding mode selection, where the algorithms are described from two distinct layers of block layer and frame layer. The decoder joins the nonlinear motion information in the side information (SI) generation, to estimate a real motion trajectory and obtain an accurate SI. Decoder motion analysis involves approaches using high-order motion model, global motion model, and local motion model. We also concern about the combination of encoder and decoder in presence of motion non-stationarity algorithms. Finally, the prospects in this field are proposed.

关键词： distributed video coding Motion non-stationarity Correlation Nonlinearity Global motion Side information

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DVC bitstream reorganiser for mobile devices

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ELECTRONICS LETTERS 2010年第17期46卷 1228-U88页

作者： Kim, C. K. Park, J. Suh, D. Y. Jeon, B. Kyung Hee Univ Coll Elect & Informat Yongin 449701 Kyunggi South Korea Sungkyunkwan Univ Dept Elect & Elect Engn Suwon 440746 South Korea

Mobile-to-mobile video communications require both an encoder and a decoder to have low complexity. distributed video coding (DVC) shifts the complexity to the decoder, resulting in a low-complexity encoder suitable for wireless transmission of videos. However, high complexity at the DVC decoder side makes it difficult for resource-constrained mobile devices to perform decoding. Proposed is a solution that is called a DVC bitstream reorganiser. This reorganiser estimates block-wise motion vectors and sends the motion information and the parity data required for decoding to the decoder which reduces the complexity associated with side information generation and repetitive channel decoding. Simulations demonstrate that the decoding speed of the proposed method is 10 to 25 times faster than before.

关键词： DVC bitstream reorganiser DVC decoder distributed video coding mobile communication mobile devices mobile-to-mobile video communications video coding

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Adaptive reconstruction scheme using neighbour pixels in PDWZ coding

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ELECTRONICS LETTERS 2010年第9期46卷 626-U43页

作者： Shim, S. -Y. Han, J. -K. Bae, J. Sejong Univ Dept Informat & Commun Engn Seoul 143747 South Korea

distributed video coding (DVC) is an emerging video coding technology that utilises information theory for distributed sources to build a very simple encoder. In the DVC codec, the reconstruction function for the Wyner-Ziv (WZ) frame is one of the most important modules for improving the quality of the decoded image. An efficient reconstruction algorithm is proposed that uses neighbour pixel information. Simulation results show that the proposed algorithm improves the quality of the decoded image without an increase in the bit rate.

关键词： DVC PDWZ coding Wyner-Ziv frame adaptive reconstruction scheme decoded image distributed video coding neighbour pixels reconstruction function video coding video coding technology

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