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Circuits and Systems for Video Technology, IEEE Transactions on

Issue 2 • Date Feb 2002

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Displaying Results 1 - 6 of 6
  • Hemiface mirroring: a new approach to reducing bandwidth requirements of audiovisual telecommunication

    Page(s): 130 - 135
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (74 KB) |  | HTML iconHTML  

    Research has shown that the sight of a speaker's face can dramatically improve the intelligibility of speech. The addition of a video stream to telecommunications systems is, therefore, a highly desirable goal. Extending the content-based coding paradigm of MPEG-4, we present a novel method of reducing the amount of data required to represent video images of human speakers. This method is based around the mirroring of vertical halves of the speaker's face. We report an experiment that compared video of synthesized speaking faces (constructed by mirroring hemifaces) with that of "normal" (un-manipulated) speaking faces. The results of the experiment show that the synthesized faces provided the same benefits to speech perception as the normal faces. Development of this technique as an image-coding technique for audiovisual telecommunication applications is discussed View full abstract»

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  • Pilot-assisted 16-level QAM for wireless video

    Page(s): 77 - 89
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (272 KB) |  | HTML iconHTML  

    This paper presents a twin-class transmission system for narrowband radio access channels suitable for handheld video phone and multimedia portable PC applications. The transmission system is comprised of a hierarchical 16-QAM modulation technique and a channel-coding scheme. The formation of dual-priority transmission is due to differing error resiliencies of the bits that make up a given symbol in a Gray-coded 16-QAM. On this basis, a twin-class pilot-assisted fade-estimation technique that can gracefully reduce the power loss caused by the transmission of pilot overhead is developed. The twin-class 16-QAM system is then used to transport a compressed video bitstream, which is partitioned to match the bit-error sensitivity of the transmitted symbol. The partitioning scheme is based on a separation of the variable-length (VL) coded discrete cosine transform (DCT) coefficients within each DCT block. This partitioning scheme is then applied to split the ITU-T H.263-coded bitstream. The scheme is suitable for constant bit-rate transmission (CBR), where the fraction of bits assigned to each of the two partitions can be adjusted according to the requirements of the unequal error protection scheme employed. The distribution of the VL-coded (VLC) information amongst the two partitions is performed adaptively. Finally, the performance of the partitioning scheme for transmission of video signals using our twin-class 16-QAM transmission system is evaluated under multipath fading conditions View full abstract»

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  • Fast and automatic video object segmentation and tracking for content-based applications

    Page(s): 122 - 129
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (258 KB) |  | HTML iconHTML  

    The new video-coding standard MPEG-4 enables content-based functionality, as well as high coding efficiency, by taking into account shape information of moving objects. A novel algorithm for segmentation of moving objects in video sequences and extraction of video object planes (VOPs) is proposed . For the case of multiple video objects in a scene, the extraction of a specific single video object (VO) based on connected components analysis and smoothness of VO displacement in successive frames is also discussed. Our algorithm begins with a robust double-edge map derived from the difference between two successive frames. After removing edge points which belong to the previous frame, the remaining edge map, moving edge (ME), is used to extract the VOP. The proposed algorithm is evaluated on an indoor sequence captured by a low-end camera as well as MPEG-4 test sequences and produces promising results View full abstract»

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  • Region-of-interest coding based on set partitioning in hierarchical trees

    Page(s): 106 - 113
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB) |  | HTML iconHTML  

    In many image-coding applications such as Web browsing, image databases, and telemedicine, it is useful to reconstruct only a region of interest (ROI) before the rest of the image is reconstructed. In this paper, an ROI coding functionality is incorporated with the set partitioning in hierarchical trees (SPIHT) algorithm for wavelet-based image coding. By placing a higher emphasis on the transform coefficients pertaining to the ROI, the ROI is coded with higher fidelity than the rest of the image in earlier stages of progressive coding. The general thrust of this research is to identify necessary coefficients in the wavelet-transform domain for the decoder to reconstruct the desired region. This new method provides better performance than the previously presented methods View full abstract»

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  • Shot-boundary detection: unraveled and resolved?

    Page(s): 90 - 105
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (289 KB) |  | HTML iconHTML  

    Partitioning a video sequence into shots is the first step toward video-content analysis and content-based video browsing and retrieval. A video shot is defined as a series of interrelated consecutive frames taken contiguously by a single camera and representing a continuous action in time and space. As such, shots are considered to be the primitives for higher level content analysis, indexing, and classification. The objective of this paper is twofold. First, we analyze the shot-boundary detection problem in detail and identify major issues that need to be considered in order to solve this problem successfully. Then, we present a conceptual solution to the shot-boundary detection problem in which all issues identified in the previous step are considered. This solution is provided in the form of a statistical detector that is based on minimization of the average detection-error probability. We model the required statistical functions using a robust metric for visual content discontinuities (based on motion compensation) and take into account all (a priori) knowledge that we found relevant to shot-boundary detection. This knowledge includes the shot-length distribution, visual discontinuity patterns at shot boundaries, and characteristic temporal changes of visual features around a boundary. Major advantages of the proposed detector are its robust and sequence-independent performance, while there is also the possibility to detect different types of shot boundaries simultaneously. We demonstrate the performance of our detector regarding two most widely used types of shot boundaries: hard cuts and dissolves View full abstract»

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  • A hybrid DCT-SVD image-coding algorithm

    Page(s): 114 - 121
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (217 KB) |  | HTML iconHTML  

    We propose an image-coding algorithm which combines the discrete cosine transform (DCT) and the singular value decomposition (SVD). The DCT is used to transform those blocks in the source image that exhibit a high correlation, while blocks with greater high-frequency content are transformed using the SVD. A simple criterion is used to decide which transform should be used on each block. Simulation results show that the new hybrid algorithm provides good distortion, bit rate, and image quality-especially in images which are less spatially correlated 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