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Circuits and Systems for Video Technology, IEEE Transactions on

Issue 6 • Date Dec. 1996

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Displaying Results 1 - 12 of 12
  • Comment on "Shape-adaptive DCT for generic coding of video"

    Page(s): 686 - 688
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (348 KB)  

    Contrary to one of the key conclusions of the paper by Sikora and Makai (see ibid., vol.5, no.1, p.5962, 1995), the cross-correlation of the one-dimensional shape-adaptive DCT (1-D SA-DCT) coefficients located in two columns of different sizes does not necessarily take maximum values at the same indices. The correct way to measure the cross-correlation of the SA-DCT coefficients after the first stage of the transform is presented. The idea of implementing shape-adaptive DCT and some aspects of their work could nevertheless be useful. View full abstract»

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  • An adaptive nearest neighbor multichannel filter

    Page(s): 699 - 703
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (964 KB)  

    This paper addresses the problem of noise attenuation for multichannel data. The proposed filter utilizes adaptively determined data-dependent coefficients based on a novel distance measure which combines vector directional with vector magnitude filtering. The special case of color image processing is studied as an important example of multichannel signal processing View full abstract»

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  • A cellular neural network for clustering-based adaptive quantization in subband video compression

    Page(s): 688 - 692
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (816 KB)  

    This paper presents a novel cellular connectionist model for the implementation of a clustering-based adaptive quantization in video coding applications. The adaptive quantization has been designed for a wavelet-based video coding system with a desired scene adaptive and signal adaptive quantization. Since the adaptive quantization is accomplished through a maximum a posteriori probability (MAP) estimation-based clustering process, its massive computation of neighborhood constraints makes it difficult for a software-based real-time implementation of video coding applications. The proposed cellular connectionist model aims at designing an architecture for the real-time implementation of the clustering-based adaptive quantization. With a cellular neural network architecture mapping onto the image domain, the powerful Gibbs spatial constraints are realized through interactions among neurons connected with their neighbors. In addition, the computation of coefficient distribution is designed as an external input to each component of a neuron or processing element (PE). We prove that the proposed cellular neural network does converge to the desired steady state with the proposed, update scheme. This model also provides a general architecture for image processing tasks with Gibbs spatial constraint-based computations View full abstract»

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  • Identification and minimization of IIR tap coefficients for the cancellation of complex multipath in terrestrial television

    Page(s): 703 - 706
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (356 KB)  

    By using a deterministic approach, an exact form for the synchronous detected video signal under a ghosted condition is presented. Information regarding the phase quadrature-induced ghost component derived from the quadrature forming nature of the vestigial sideband (VSB) filter is obtained by crosscorrelating the detected video with the ghost cancel reference (GCR) signal. As a result, the minimum number of taps required to correctly remove all the ghost components is subsequently presented. The results are applied to both National Television System Committee (NTSC) and phase alternate line (PAL) television View full abstract»

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  • A regressive structure for on-line computation of arbitrary length DCT-IV and DST-IV transforms

    Page(s): 692 - 695
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (464 KB)  

    We demonstrate that the forward and inverse type-IV discrete cosine transform (DCT-IV/IDCT-IV) and type-IV discrete sine transform (DST-IV/IDST-IV) can be efficiently computed by a regressive structure. In our approach, we suggest using the recursive sinusoidal formulas corresponding to the transform kernels of these transforms to obtain an IIR filter structure. The novel structure is then used for parallel computation of arbitrary length DCT-IV/IDCT-IV and DST-IV/IDST-IV. Since the architecture can be highly parallel, simple, and regular, it is most suitable for VLSI implementation. Moreover, we do not need to permute the input sequence, which makes the approach particularly suitable for on-line computation View full abstract»

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  • Use of two-dimensional deformable mesh structures for video coding. II. The analysis problem and a region-based coder employing an active mesh representation

    Page(s): 647 - 659
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2760 KB)  

    For pt.I see ibid., vol.6, no.6, p.636-46 (1996). This paper explores the use of the deformable mesh structure for motion/shape analysis and synthesis in an image sequence. We present algorithms for the analysis problem, including scene-adaptive mesh generation and node tracking over successive frames. We also describe a region-based video coder that integrates the analysis and synthesis algorithms presented. The coder describes each region by an ensemble of connected quadrilateral elements embedded in a mesh structure. For each region, its shape and texture are described by the nodal positions and image functions of the elements in this region in an initial frame, while its motion (including shape deformation) is characterized by the nodal trajectories in the following frames, which are in turn specified by a few motion parameters. This coder has been applied to a typical common intermediate format (CIF) resolution, head-and-shoulder type sequence. The visual quality is significantly better than the H.263-TMN4 algorithm at about 50 kb/s (for the luminance component only, 30 Hz) View full abstract»

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  • A fast hierarchical motion-compensation scheme for video coding using block feature matching

    Page(s): 627 - 635
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (844 KB)  

    This paper presents a fast hierarchical feature matching-motion estimation scheme (HFM-ME) that can be used in H.263, H.261, MPEG 1, MPEG 2, and HDTV applications. In the HFM-ME scheme, the sign truncated feature (STF) is defined and used for block template matching, as opposed to the pixel intensity values used in conventional block matching methods. The STF extraction process can be considered as a zero-crossing phase detection with the mean as the bias and binary sign pattern as the phase deviation. Using the STF definition, a data block can be represented by a mean and a set of binary features with a much reduced data set. The block matching motion estimation is then divided into mean matching and binary phase matching. The proposed technique enables a significant reduction in computational complexity compared with the conventional full-search block matching ME because binary phase matching only involves Boolean logic operations. This feature also significantly reduces the data transfer time between the frame buffer and motion estimator. The proposed HFM-ME algorithm is implemented and compared with the conventional full-search block matching schemes. Our test results using three full-motion MPEG sequences indicate that the performance of the HFM-ME is comparable with the full-search block matching under the same search ranges, however, HFM-ME can be implemented about 64 times faster than the conventional full-search schemes. The proposed scheme can be combined with other fast algorithms to further reduce the computational complexity, at the expense of picture quality View full abstract»

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  • Variable block size coding of images with hybrid quantization

    Page(s): 679 - 685
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1444 KB)  

    This paper describes a progressive image transmission (PIT) scheme using a variable block size coding technique in conjunction with a variety of quantization schemes in the transform domain. The proposed scheme uses a region growing technique to partition the images so that regions of different sizes can be addressed using a small amount of side information. This segmentation divides the image into five different regions that vary in size based on the details within the image. High detail blocks are classified into four different categories based on the energy distribution followed by vector quantization (VQ), and low-detail blocks are encoded with scalar quantization (SQ). Progressive refinement is achieved by proper masking of the information in the transform domain. Simulation results show that the reconstructed images preserve fine and pleasant qualities based on both subjective and mean square error criteria. Also, the receiver reconstructs more details in each stage so that the observer can recognize the image quickly View full abstract»

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  • Optimal variable-rate mean-gain-shape vector quantization for image coding

    Page(s): 660 - 668
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (880 KB)  

    A method for rate-distortion optimal variable rate mean-gain-shape vector quantization (MGSVQ) is presented with application to image compression. Conditions are derived within an entropy-constrained product code framework that result in an optimal bit allocation between mean, gain, and shape vectors at all rates. An extension to MGSVQ called hierarchical mean-gain-shape vector quantization (HMGSVQ) is similarly introduced. By considering the statistical dependence between adjacent means, this method is able to provide an improvement in the rate-distortion performance over traditional MGSVQ, especially at low bit rates. Simulation results are provided to demonstrate the rate-distortion performance of MGSVQ and HMGSVQ for image data View full abstract»

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  • Use of two-dimensional deformable mesh structures for video coding .I. The synthesis problem: mesh-based function approximation and mapping

    Page(s): 636 - 646
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1076 KB)  

    This paper explores the use of a deformable mesh (also known as the control grid) structure for motion analysis and synthesis in an image sequence. We focus on the synthesis problem, i.e., how to interpolate an image function given nodal positions and values and how to predict a present image frame from a reference one given nodal displacements between the two images. For this purpose, we review the fundamental theory and numerical techniques that have been developed in the finite element method for function approximation and mapping using a mesh structure. Specifically, we focus on (i) the use of shape functions for node-based function interpolation and mapping; and (ii) the use of regular master elements to simplify numerical calculations involved in dealing with irregular mesh structures. In addition to a general introduction that is applicable to an arbitrary mesh structure, we also present specific results for triangular and quadrilateral mesh structures, which are the most useful two-dimensional (2-D) meshes. Finally, we describe how to apply the above results for motion compensated frame prediction and interpolation. It is shown that the concepts of shape functions and master elements are crucial for developing computationally efficient algorithms for both the analysis and synthesis problems View full abstract»

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  • Postprocessing of late cells for packet video

    Page(s): 669 - 678
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    A method for preventing accumulation of image artifacts due to cell loss in packet video is presented. At each ATM switching node an auxiliary buffer is used to store the overflow traffic of the main switching buffer. The main buffer is served with an absolute priority over the auxiliary buffer. Decoded pictures are normally reconstructed from the cells of the main buffer. The late cells received from the auxiliary buffer are processed and properly added to the current decoded picture. Postprocessing of these cells for the standard video codecs such as H.261 and MPEG is presented. It is shown that although the picture quality due to cell loss is temporarily degraded, it is immediately brought back to its original quality upon the reception of the late cells, as if no loss has occurred View full abstract»

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  • A parallel video converter for displaying 4:3 images on 16:9 HDTV receivers

    Page(s): 695 - 699
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB)  

    The 16/9 widescreen TV is becoming popular in the marketplace; however, its aspect ratio is not compatible with the conventional 4/3 SDTV program. We propose a nonuniform conversion to efficiently display 4/3 SDTV programs on a 16/9 high-definition television (HDTV) monitor, for real time HDTV receivers, a parallel video converter is also proposed using nonuniform interpolation. To trade off complexity and performance, we only use one field-memory and one line-buffer for motion adaptation to interpolate the pixels, which can be finished by the parallel computation kernel in one clock cycle. In order to combine parallel computation, the memory-slice method is employed, which is efficiently controlled by a state machine for nonuniform interpolation. With parallel conversion, a high-speed video converter can be achieved for advanced HDTV receivers 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