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Circuits and Systems for Video Technology, IEEE Transactions on

Issue 8 • Date Dec. 1999

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Displaying Results 1 - 15 of 15
  • Introduction to the special issue on object-based video coding and description

    Publication Year: 1999 , Page(s): 1144 - 1146
    Cited by:  Papers (1)
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    Freely Available from IEEE
  • Author index

    Publication Year: 1999 , Page(s): 1 - 5
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    Freely Available from IEEE
  • Subject index

    Publication Year: 1999 , Page(s): 5 - 15
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    Freely Available from IEEE
  • Rate control and bit allocation for MPEG-4

    Publication Year: 1999 , Page(s): 1243 - 1258
    Cited by:  Papers (32)  |  Patents (49)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (712 KB)  

    In previous years, an interest has developed in the coded representations of video signals allowing independent manipulation of semantically independent elements (objects). Along these lines, the ISO standard MPEG-4 enhances the traditional concept of the video sequence to convert it into a synchronized set of visual objects organized in a flexible way. The real-time generation of a bitstream according to this new paradigm, and suitable for its transmission through either fixed- or variable-rate channels, results in a challenging new bit allocation and rate control problem, which has to satisfy complex application requirements. This paper formalizes this new issue by focusing on the design of rate control systems for real-time applications. The proposed approach relies on the modelization of the source and the optimization of a cost criterion based on signal quality parameters. Different cost criteria are provided, corresponding to a set of relevant definitions of the object priority concept. Algorithms are introduced to minimize the average distortion of the objects, to guarantee desired qualities to the most relevant ones, and to keep constant ratios among the object qualities. The techniques have been applied to a coder implementing the MPEG-4 video verification model, showing good properties in terms of achievement of the control objectives View full abstract»

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  • Implementing multiplexing, streaming, and server interaction for MPEG-4

    Publication Year: 1999 , Page(s): 1299 - 1311
    Cited by:  Papers (2)  |  Patents (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (464 KB)  

    We describe the implementation of a streaming client-server system for object-based audio-visual presentations in general and MPEG-4 content in particular. The system augments the MPEG-4 demonstration software implementation (IM1) for PCs by adding network-based operation with full support for the Delivery Multimedia Integration Framework (DMIF) specification, a streaming PC-based server with DMIF support (via Xbind Inc.'s XDMIF suite), and multiplexing software. We describe XDMIF, the first reference implementation of the DMIF specification. The MPEG-4 server is designed for delivering object-based audio-visual presentation. We discuss the issues in the design and implementation of MPEG-4 servers. The system also implements a novel architecture for client-server interaction in object-based audio-visual presentations, using the mechanism of command routes and command descriptors. This new concept of command routes and command descriptors is useful in developing sophisticated interactive applications View full abstract»

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  • Efficient video indexing scheme for content-based retrieval

    Publication Year: 1999 , Page(s): 1269 - 1279
    Cited by:  Papers (61)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (676 KB)  

    Extracting a small number of key frames that can abstract the content of video is very important for efficient browsing and retrieval in video databases. In this paper, the key frame extraction problem is considered from a set-theoretic point of view, and systematic algorithms are derived to find a compact set of key frames that can represent a video segment for a given degree of fidelity. The proposed extraction algorithms can be hierarchically applied to obtain a tree-structured key frame hierarchy that is a multilevel abstract of the video. The key frame hierarchy enables an efficient content-based retrieval by using the depth-first search scheme with pruning., Intensive experiments on a variety of video sequences are presented to demonstrate the improved performance of the proposed algorithms over the existing approaches View full abstract»

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  • MPEG-4 standardized methods for the compression of arbitrarily shaped video objects

    Publication Year: 1999 , Page(s): 1170 - 1189
    Cited by:  Papers (52)  |  Patents (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (572 KB)  

    MPEG-4 is the most recent standard for audio-visual representation to be published by the International Organization for Standardization. One of the many new features of MPEG-4 is its ability to represent two-dimensional video objects of arbitrary shape. For this purpose, MPEG-4 uses the conventional motion-compensated discrete cosine transform syntax for color/texture coding and augments this with an explicit compressed representation of the video object's shape. This paper is intended as a tutorial in the means of encoding and decoding arbitrarily shaped video objects as specified by MPEG-4. The major emphasis of the paper is on explaining the compression technology associated with the normative shape representation, i.e., block-based context-based arithmetic encoding, but some new aspects associated with arbitrarily shaped texture coding are also highlighted. The MPEG-4 specifications are presented in an informal way, and the motivations underlying the algorithm are clarified. In addition, effective methods are suggested for performing many of the nonnormative encoding tasks, and several encoding performance tradeoffs are illustrated View full abstract»

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  • Region-based representations of image and video: segmentation tools for multimedia services

    Publication Year: 1999 , Page(s): 1147 - 1169
    Cited by:  Papers (95)  |  Patents (21)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1000 KB)  

    This paper discusses region-based representations of image and video that are useful for multimedia services such as those supported by the MPEG-4 and MPEG-7 standards. Classical tools related to the generation of the region-based representations are discussed. After a description of the main processing steps and the corresponding choices in terms of feature spaces, decision spaces, and decision algorithms, the state of the art in segmentation is reviewed. Mainly tools useful in the context of the MPEG-4 and MPEG-7 standards are discussed. The review is structured around the strategies used by the algorithms (transition based or homogeneity based) and the decision spaces (spatial, spatio-temporal, and temporal). The second part of this paper proposes a partition tree representation of images and introduces a processing strategy that involves a similarity estimation step followed by a partition creation step. This strategy tries to find a compromise between what can be done in a systematic and universal way and what has to be application dependent. It is shown in particular how a single partition tree created with an extremely simple similarity feature can support a large number of segmentation applications: spatial segmentation, motion estimation, region-based coding, semantic object extraction, and region-based retrieval View full abstract»

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  • An integrated scheme for automated video abstraction based on unsupervised cluster-validity analysis

    Publication Year: 1999 , Page(s): 1280 - 1289
    Cited by:  Papers (114)  |  Patents (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (348 KB)  

    Key frames and previews are two forms of a video abstract, widely used for various applications in video browsing and retrieval systems. We propose in this paper a novel method for generating these two abstract forms for an arbitrary video sequence. The underlying principle of the proposed method is the removal of the visual-content redundancy among video frames. This is done by first applying multiple partitional clustering to all frames of a video sequence and then selecting the most suitable clustering option(s) using an unsupervised procedure for cluster-validity analysis. In the last step, key frames are selected as centroids of obtained optimal clusters. Video shots, to which key frames belong, are concatenated to form the preview sequence View full abstract»

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  • An integrated approach for content-based video object segmentation and retrieval

    Publication Year: 1999 , Page(s): 1259 - 1268
    Cited by:  Papers (36)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    Object-based video data representations enable unprecedented functionalities of content access and manipulation. We present an integrated approach using region-based analysis for semantic video object segmentation and retrieval. We first present an active system that combines low-level region segmentation with user inputs for defining and tracking semantic video objects. The proposed technique is novel in using an integrated feature fusion framework for tracking and segmentation at both region and object levels. Experimental results and extensive performance evaluation show excellent results compared to existing systems. Building upon the segmentation framework, we then present a unique region-based query system for semantic video object. The model facilitates powerful object search, such as spatio-temporal similarity searching at multiple levels View full abstract»

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  • A VOP generation tool: automatic segmentation of moving objects in image sequences based on spatio-temporal information

    Publication Year: 1999 , Page(s): 1216 - 1226
    Cited by:  Papers (52)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (672 KB)  

    The new MPEG-4 video coding standard enables content-based functionalities. In order to support the philosophy of the MPEG-4 visual standard, each frame of video sequences should be represented in terms of video object planes (VOPs). In other words, video objects to be encoded in still pictures or video sequences should be prepared before the encoding process starts. Therefore, it requires a prior decomposition of sequences into VOPs so that each VOP represents a moving object. This paper addresses an image segmentation method for separating moving objects from the background in image sequences. The proposed method utilizes the following spatio-temporal information. (1) For localization of moving objects in the image sequence, two consecutive image frames in the temporal direction are examined and a hypothesis testing is performed by comparing two variance estimates from two consecutive difference images, which results in an F-test. (2) Spatial segmentation is performed to divide each image into semantic regions and to find precise object boundaries of the moving objects. The temporal segmentation yields a change detection mask that indicates moving areas (foreground) and nonmoving areas (background), and spatial segmentation produces spatial segmentation masks. A combination of the spatial and temporal segmentation masks produces VOPs faithfully. This paper presents various experimental results View full abstract»

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  • Long-term global motion estimation and its application for sprite coding, content description, and segmentation

    Publication Year: 1999 , Page(s): 1227 - 1242
    Cited by:  Papers (66)  |  Patents (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2144 KB)  

    We present a new technique for long-term global motion estimation of image objects. The estimated motion parameters describe the continuous and time-consistent motion over the whole sequence relatively to a fixed reference coordinate system. The proposed method is suitable for the estimation of affine motion parameters as well as for higher order motion models like the parabolic model-combining the advantages of feature matching and optical flow techniques. A hierarchical strategy is applied for the estimation, first translation, affine motion, and finally higher order motion parameters, which is robust and computationally efficient. A closed-loop prediction scheme is applied to avoid the problem of error accumulation in long-term motion estimation. The presented results indicate that the proposed technique is a very accurate and robust approach for long-term global motion estimation, which can be used for applications such as MPEG-4 sprite coding or MPEG-7 motion description. We also show that the efficiency of global motion estimation can be significantly increased if a higher order motion model is applied, and we present a new sprite coding scheme for on-line applications. We further demonstrate that the proposed estimator serves as a powerful tool for segmentation of video sequences View full abstract»

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  • Content analysis of video using principal components

    Publication Year: 1999 , Page(s): 1290 - 1298
    Cited by:  Papers (30)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (836 KB)  

    We use principal component analysis (PCA) to reduce the dimensionality of features of video frames for the purpose of content description. This low-dimensional description makes practical the direct use of all the frames of a video sequence in later analysis. The PCA representation circumvents or eliminates several of the stumbling blocks in current analysis methods and makes new analyses feasible. We demonstrate this with two applications. The first accomplishes high-level scene description without shot detection and key-frame selection. The second uses the time sequences of motion data from every frame to classify sports sequences View full abstract»

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  • Video segmentation for content-based coding

    Publication Year: 1999 , Page(s): 1190 - 1203
    Cited by:  Papers (71)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (688 KB)  

    To provide multimedia applications with new functionalities, the new video coding standard MPEG-4 relies on a content-based representation. This requires a prior decomposition of sequences into semantically meaningful, physical objects. We formulate this problem as one of separating foreground objects from the background based on motion information. For the object of interest, a 2D binary model is derived and tracked throughout the sequence. The model points consist of edge pixels detected by the Canny operator. To accommodate rotation and changes in shape of the tracked object, the model is updated every frame. These binary models then guide the actual video object plane (VOP) extraction. Thanks to our new boundary postprocessor and the excellent edge localization properties of the Canny operator, the resulting VOP contours are very accurate. Both the model initialization and update stages exploit motion information. The main assumption underlying our approach is the existence of a dominant global motion that can be assigned to the background. Areas that do not follow this background motion indicate the presence of independently moving physical objects. Two alternative methods to identify such objects are presented. The first one employs a morphological motion filter with a new filter criterion, which measures the deviation of the locally estimated optical flow from the corresponding global motion. The second method computes a change detection mask by taking the difference between consecutive frames. The first version is more suitable for sequences with little motion, whereas the second version is better at dealing with faster moving or changing objects. Experimental results demonstrate the performance of our algorithm View full abstract»

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  • A video segmentation algorithm for hierarchical object representations and its implementation

    Publication Year: 1999 , Page(s): 1204 - 1215
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (644 KB)  

    This paper describes a segmentation algorithm for generating hierarchical object representations of images and image sequences. Starting from an object model, we describe the structure of the corresponding segmentation algorithm including all analysis methods applied. Besides the well-known color and motion analysis, we also show how to utilize shape information. Furthermore, we discuss the tradeoff between reducing the computational complexity and the quality of the segmentation results. Last, we present the implementation concept for our analysis model, which uses a special toolbox model. The toolbox provides a set of addressing schemes that are needed by low-level video processing tools. The low-level tools are functions that apply a single operation to all pixels in one frame. Using these addressing functions makes it easy to implement new video processing tools, which, when combined, form new analysis methods. The toolbox exists in C-code and is partially transferred into VHDL View full abstract»

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Aims & Scope

The emphasis is focused on, but not limited to:
1. Video A/D and D/ A
2. Video Compression Techniques and Signal Processing
3. Multi-Dimensional Filters and Transforms
4. High Speed Real-Tune Circuits
5. Multi-Processors Systems—Hardware and Software
6. VLSI Architecture and Implementation for Video Technology 

 

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Dan Schonfeld
Multimedia Communications Laboratory
ECE Dept. (M/C 154)
University of Illinois at Chicago (UIC)
Chicago, IL 60607-7053
tcsvt-eic@tcad.polito.it

Managing Editor
Jaqueline Zelkowitz
tcsvt@tcad.polito.it