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A LAYERED coding SYSTEM FOR VERY-LOW BIT-RATE VIDEO coding

SIGNAL PROCESSING-IMAGE COMMUNICATION 1995年第4-6期7卷 267-278页

作者： MUSMANN, HG Institut für Theoretische Nachrichtentechnik und Informationsverarbeitung Universität Hannover Germany

Known coding techniques for transmitting moving images at very low bit rates are explained by the source models on which these coding techniques are based. It is shown that with motion-compensated hybrid coding, object-based analysis-synthesis coding, knowledge-based coding and semantic coding, there is a consistent development of source models. In consequence these coding techniques can be combined in a layered coding system. From experimental results obtained for object-based analysis-synthesis, coding estimates for the coding efficiency of such a layered coding system are derived using head and shoulder video telephone test sequences. It is shown that an additional compression factor of about 3 can be expected with such a complex layered coding system, when compared to block-based hybrid coding.

关键词： VIDEO coding OBJECT-based coding KNOWLEDGE-based coding model-based coding

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Recent and current research on very low bit-rate video coding in Japan

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IEICE TRANSACTIONS ON COMMUNICATIONS 1996年第10期E79B卷 1415-1424页

作者： Kaneko, M Department of Information and Communication Engineering School of Engineering University of Tokyo Tokyo 113 Japan

This paper presents an overview of research activities in Japan in the field of very low bit-rate video coding. Related research based on the concept of ''intelligent image coding'' started in the mid-1980's. Although this concept originated from the consideration of a new type of image coding, it can also be applied to other interesting applications such as human interface and psychology. On the other hand, since the beginning of the 1990's, research on the improvement of waveform coding has been actively performed to realize very low bit-rate video coding. Key techniques employed here are improvement of motion compensation and adoption of region segmentation. In addition to the above, we propose new concepts of image coding, which have the potential to open up new aspects of image coding, e.g. ideas of interactive image coding, integrated 3-D visual communication and coding of multimedia information considering mutual relationship amongst various media.

关键词： very low bit-rate video coding intelligent image coding model-based coding waveform coding motion compensation region segmentation integrated 3-D visual communication

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An approach to distributed video coding using 3D face models

An approach to distributed video coding using 3D face models

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IEEE International Conference on Image Processing (ICIP 2006)

作者： Artigas, Xavi Torres, Luis Tech Univ Catalonia Barcelona Spain

ISBN: (纸本)9781424404810

Distributed Source coding (DSC), formulated thirty years ago, is lately witnessing a great research effort. This effort is encouraged by emerging new applications that could greatly benefit from the properties inherent to DSC, like low complexity encoders and embedded error resilience. Among the challenging topics related to DSC there is the generation of the Side Information, an estimation made by the decoder of the information being decoded. This paper quickly summarizes the theoretical bases of DSC and then focuses on the essential task of generating the Side Information, by developing the model-based method drafted by the authors on a previous publication. It is shown that the application of model-based Side Information generation techniques on top of current state of the art DSC-based video codecs provides an improvement of 0.5 to 0.75dB over a wide range of bit-rates. Comparisons against H.264 are also provided.

关键词： distributed video coding Wyner-Ziv coding side information model-based coding

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VIDEO SEQUENCE QUANTIZER FOR VERY-LOW BIT-RATE MOVING PICTURE coding

VIDEO SEQUENCE QUANTIZER FOR VERY-LOW BIT-RATE MOVING PICTUR...

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Conference on Visual Communications and Image Processing 94

作者： YAMADA, A OHTA, M NISHITANI, T NEC CORP LTD INFORMAT TECHNOL RES LABSMIYAMAE KUKAWASAKIKANAGAWA 216JAPAN

ISBN: (纸本)081941638X

This paper describes a novel intelligent low bit rate coding technique for motion pictures, named Video Sequence Quantizer (VSQ). VSQ is one of the semantic coding. The concept is very simple. The encoder extracts motion information about target objects and transmit it as a few control parameters. The decoder has several video sequences in its database and outputs them selectively according to the transmitted parameters. It can reproduce natural movements with a simple operation compared with another semantic coding scheme called computer graphics model-based coding. We make clear the concept of VSQ and also apply it to a very low bit rate TV phone system. Computer simulation of TV phone has been done using twelve video sequences. It can naturally reproduce the speaker's movements by 80 bit/sec. VSQ is a very simple but basic concept for video coding. It will be also useful for mobile and multimedia communications.

关键词： LOW BIT RATE coding model-based coding KNOWLEDGE-based coding SEMANTIC coding VIDEO coding TV-PHONE SYSTEM VECTOR QUANTIZER MOTION REPRODUCTION COMPUTER GRAPHICS VIDEO SEQUENCE

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Motion tracking of human mouth by generalized deformable models

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PATTERN RECOGNITION LETTERS 1999年第9期20卷 879-887页

作者： Chan, SY Ngo, CW Lai, KF Nanyang Technol Univ Sch Appl Sci Singapore 63978 Singapore Kent Ridge Digital Labs Singapore 119613 Singapore

We propose and evaluate four trackers for tracking the shape, motion and deformation of a human mouth in video sequences. The trackers are suitable for use in very low bitrate video coding systems. (C) 1999 Elsevier S... 详细信息

关键词： motion tracking deformable models model-based coding

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model-based global and local motion estimation for videoconference sequences

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2004年第9期14卷 1156-1161页

作者： Calvagno, G Fantozzi, F Rinaldo, R Viareggio, A Univ Padua Dipartimento Ingn Informaz I-35131 Padua Italy Univ Udine Dipartimento Ingn Elettr Gest & Meccan I-33100 Udine Italy

In this work, we present an algorithm for face 3-D motion estimation in videoconference sequences. The algorithm is able to estimate both the position of the face as an object in 3-D space (global motion) and the movements of portions of the face, like the mouth or the eyebrows (local motion). The algorithm uses a modified version of the standard 3-D face model CANDIDE. We present various techniques to increase robustness of the global motion estimation which is based on feature tracking and an extended Kalman filter. Global motion estimation is used as a starting point for local motion detection in the mouth and eyebrow areas. To this purpose, synthetic images of these areas (templates),are generated with texture mapping techniques, and then compared to the corresponding regions in the current frame. A set of parameters, called action unit vectors (AUVs) influences the shape of the synthetic mouth and eyebrows. The optimal AUV values are determined via a gradient-based minimization procedure of the error energy between the templates and the actual face areas. The proposed scheme is robust and was tested with success on sequences of many hundreds of frames.

关键词： adaptive Kalman filtering block matching eyebrow tracking face tracking feature tracking lip tracking model-based coding template matching

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The clustered causal state algorithm - Efficient pattern discovery for lossy data-compression applications

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COMPUTING IN SCIENCE & ENGINEERING 2006年第5期8卷 59-67页

作者： Schmiedekamp, Mendel Subbu, Aparna Puoha, Shashi Penn State Univ Intelligent Control Dept Informat Sci & Technol Div Appl Res Lab University Pk PA 16802 USA

Pattern discovery is a potential boon for data compression, but current approaches are inefficient and produce cumbersome pattern descriptions. The clustered causal state algorithm is a new pattern-discovery algorithm... 详细信息

关键词： clustering model-based coding pattern analysis real-time systems statistical pattern models clustering model-based coding pattern analysis real-time systems statistical pattern models

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Representing and compressing facial animation parameters using facial action basis functions

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1999年第3期9卷 405-410页

作者： Ahlberg, J Li, HB Linkoping Univ Dept Elect Engn Image Coding Grp S-58183 Linkoping Sweden

In model-based, or semantic, coding, parameters describing the nonrigid motion of objects, e.g., the mimics of a face, are of crucial interest. The facial animation parameters (FAP's) specified in MPEG-4 compose a very rich set of such parameters, allowing a wide range of facial motion. However, the FAP's are typically correlated and also constrained in their motion due to the physiology of the human face. We seek here to utilize this spatial correlation to achieve efficient compression. As it does not introduce: any interframe delay, the method is suitable for interactive applications, e.g., videophone and interactive video, where low delay is a vital issue.

关键词： face animation model-based coding MPEG-4 semantic coding synthetic/natural hybrid coding

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Tracking a detected face with dynamic programming

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IMAGE AND VISION COMPUTING 2006年第6期24卷 573-580页

作者： Yao, Zhengrong Li, Haibo Umea Univ Digital Media Lab S-90187 Umea Sweden

In this paper, we consider the problem of tracking a Moving human face in front of a video camera in real-time for a model-based coding application. The 3D head tracking in a MBC system could be implemented sequentially as 2D location tracking, coarse 3D orientation estimation and accurate 3D motion estimation. This work focuses on the 2D location tracking of one face object through continuously using a face detector. The face detection scheme is based on a boosted cascade of simple Haar-like feature classifiers. Although such a detector demonstrated rapid processing speed, high detection rate can only be achieved for rather strictly near front faces. This introduces the 'loss of tracking' problem when used in 2D tracking. This paper suggests an easy method of solving the pose problem by using the technique of Dynamic Programming. The Haar-like facial features used in the 2D face detector are spatially arranged into a 1D deformable face graph and the Dynamic Programming matching is used to handle the 'loss of track' problem. Dynamic Programming matches the deformed version of the face graph extracted from a rotated face with the template taken online before 'loss of tracking' happens. Since the deformable face graph covers a big pose variation, the developed technique is robust in tracking rotated faces. Embedding Haar-like facial features into a deformable face graph is the key feature Of Our tracking scheme. A real time tracking system based on this technique has been set tip and tested. Encouraging results have been got and are reported. (c) 2005 Elsevier B.V. All rights reserved.

关键词： model-based coding face tracking face detection Dynamic Programming

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CBIT - Context-based image transmission

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IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE 2001年第2期5卷 159-170页

作者： Salous, MN Pycock, D Cruickshank, GS Univ Birmingham Sch Elect & Elect Engn Birmingham B15 2TT W Midlands England Queen Elizabeth Hosp Dept Neurosurg Birmingham B15 2TH W Midlands England

Few networks offer sufficient bandwidth for the transmission of high resolution two- and three-dimensional medical image sets without incurring significant latency. Traditional compression methods achieve bit-rate reduction based on pixel statistics and ignore visual cues that are important in identifying visually informative regions. This paper describes an approach to managing image transmission in which spatial regions are selected and prioritized for transmission so that visually informative data is received in a timely manner. This context-based image transmission (CBIT) scheme is a lossless form of progressive image transmission (PIT) in which gross structure, represented by an approximate iconic image, is transmitted first. Each part of this iconic image is progressively updated, using a simple set of rules that take into account viewing requirements. CBIT is realized using knowledge about image composition to segment, label, prioritize, and fit geometric models to regions of an image. Tests, using neurological images, show that, with CBIT, a valuable transmitted image is received with a latency that is about one-tenth that of traditional PIT schemes. Frequently, the necessary regions of the image are transmitted in about half the time taken to transmit the full image.

关键词： knowledge-based segmentation model-based coding progressive image transmission teleradiology

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