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Circuits and Systems for Video Technology, IEEE Transactions on

Issue 3 • Date Jun 1993

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Displaying Results 1 - 9 of 9
  • ATM networking and video-coding techniques for QOS control in B-ISDN

    Publication Year: 1993 , Page(s): 175 - 181
    Cited by:  Papers (3)  |  Patents (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (688 KB)  

    Integration of video services are addressed. The view that various types of end-to-end quality of service (QOS) for video communications, ranging from videophone to high-definition television (HDTV), should be supported to utilize broadband integrated services digital network (B-ISDN) services and video data is expressed. End-to-end QOS is recognized as a function of terminal capability and network performance. The key feature of B-ISDN is that both terminal capability and network performance are selectable and controllable. In order to capture the basic characteristics of end-to-end QOS, it is necessary to conduct experiments using a prototype system. A prototype system comprising an asynchronous transfer mode (ATM) switch and video codecs is presented. The ATM switch is based on distributed-memory-switch architecture and it will provide for nonblocking cell-switching capability with a very low cell-transfer delay. Developed codecs conform to H.261 with an additional function of controlling average coding bit rate. The coding bit rate is chosen as a parameter of terminal capability and the cell-loss ratio is chosen as a parameter of network performance. From experiments using a prototype system, a relationship between coding bit rate and cell-loss ratio is obtained View full abstract»

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  • Statistical characterization and block-based modeling of motion-adaptive coded video

    Publication Year: 1993 , Page(s): 199 - 207
    Cited by:  Papers (17)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB)  

    The statistical characteristics of full-motion video sources using motion-adaptive variable-bit-rate coding techniques is studied. Analytical models are developed to describe the behavior of the coded video signals based on the encoder structure. The video-compression algorithm used is in compliance with the general MPEG syntax and bit-stream definition. Statistical characteristics associated with each block type and their aggregate are presented. A composite model to represent the number of bits per field for the encoded video traffic that comprises multiple autoregressive models for the number of blocks per field and the number of bits in each coded block is derived. The statistics measured from a sample video sequence are compared to those obtained by the model and it is observed that the model captures the coded video behavior for each block type and their combination reasonably well. This model can be used to further study the cell-generation process of full-motion video codecs and the aggregation of such video sources at the statistical multiplexers View full abstract»

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  • Variable-bit-rate HDTV codec with ATM-cell-loss compensation

    Publication Year: 1993 , Page(s): 230 - 237
    Cited by:  Papers (9)  |  Patents (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (728 KB)  

    A variable-bit-rate coding algorithm based on motion-adaptive discrete cosine transform (DCT) is investigated for asynchronous transfer mode (ATM) environments in broadband integrated-services digital networks (B-ISDN). The algorithm effectively reduces the bit rate, in particular, for HDTV-picture sources with little motion. Adaptive two-layered coding, an ATM cell matrix for error correction, and a block interleave for error concealment are proposed to keep picture quality high by compensating for ATM cell loss. A feedforward control scheme for variable-length coding (VLC), a multimode quantization that restricts peak bit rate and average bit rate, is also proposed for traffic control. Experimental hardware is shown to reduce the coding bit rate for pictures of HDTV conference applications to peak bit rate of 65-Mb/s and an average bit rate of 10-20-Mb/s in ATM environments View full abstract»

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  • Adaptive quadtree coding of motion-compensated image sequences for use on the broadband ISDN

    Publication Year: 1993 , Page(s): 222 - 229
    Cited by:  Papers (6)  |  Patents (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (796 KB)  

    An image-coding technique is described in which an adaptive quadtree scheme is used to encode motion-compensated difference images. A mechanism is determined within the encoding process that allows a predetermined level of image quality to be selected by the user at call setup time and then maintained by the encoder. The coder operates in a variable-bit-rate mode providing a video service of near-constant image quality. A multilayered version of the coding scheme is also described in which the degradation caused by cell loss during transmission can be limited in its effect and removed completely within a short period of time. The recovery from cell loss is achieved by sending blocks from the original image sequence whenever cells are known to have been deleted by the local-network access node View full abstract»

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  • Advanced packet-video coding based on layered VQ and SBC techniques

    Publication Year: 1993 , Page(s): 208 - 221
    Cited by:  Papers (28)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1632 KB)  

    The performances of two subband-coding-vector-quantization (SBC-VQ) schemes (a quadrature-mirror-filter-based SBC with trained-codebook VQ and a parallel-filterbank SBC with lattice VQ) are compared to that of a DCT-SQ (discrete-cosine-transform-scalar-quantization) scheme as it is used in present image-coding standards. Two-layer versions of these spatial coders are evaluated in a hybrid combination with motion-compensation prediction for interframe data compression. As the SBC scheme with lattice VQ is found to perform the best, this coding scheme is further investigated in combination with more sophisticated interframe-data-compression schemes. The motion-compensated 3-D SBC coder with lattice VQ was found to outperform the techniques used in current standard coders by several dBs in the compression of interlaced CCIR 601 sequences. The performance of this coder is extremely robust in the presence of asynchronous transfer mode (ATM) cell losses due to the nonrecursive decoder structure View full abstract»

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  • Bandwidth-allocation schemes for variable-bit-rate MPEG sources in ATM networks

    Publication Year: 1993 , Page(s): 190 - 198
    Cited by:  Papers (42)  |  Patents (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (820 KB)  

    The complex traffic characteristics of variable-bit-rate (VBR) video sources makes them difficult to accommodate in asynchronous-transfer-mode (ATM) networks. To efficiently transport these services will require both an understanding of the source traffic and novel network control schemes. The performance of variable-bandwidth-allocation schemes that estimate the required bandwidth for a VBR Motion Picture Experts Group (MPEG) video source is studied using a simple prediction algorithm. The advantages of using a layered MPEG coder over the standard MPEG coder are discussed. A method for controlling a layered MPEG coder to reduce the effect of cell losses when compared to a standard MPEG coder is demonstrated View full abstract»

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  • Coding and cell-loss recovery in DCT-based packet video

    Publication Year: 1993 , Page(s): 248 - 258
    Cited by:  Papers (90)  |  Patents (95)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1220 KB)  

    The applications of discrete cosine transform (DCT)-based image and video-coding methods in the asynchronous transfer mode (ATM) environment are considered. Coding and reconstruction mechanisms are jointly designed to achieve a good compromise among compression gain, system complexity, processing delay, error-concealment capability, and reconstruction quality. The Joint Photographic Experts Group (JPEG) and Motion Picture Experts Group (MPEG) algorithms for image and video compression are modified to incorporate block interleaving in the spatial domain and DCT coefficient segmentation in the frequency domain to conceal the errors due to packet loss. A new algorithm is developed that recovers the damaged regions by adaptive interpolation in the spatial, temporal, and frequency domains. The weights used for spatial and temporal interpolations are varied according to the motion content and loss patterns of the damaged regions. When combined with proper layered transmission, the proposed coding and reconstruction methods can handle very high packet-loss rates at only a slight cost in compression gain, system complexity, and processing delay View full abstract»

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  • A traffic-control algorithm for ATM networks

    Publication Year: 1993 , Page(s): 182 - 189
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (752 KB)  

    A statistical analysis of a typical videophone scene is presented. The approach to the traffic-control problem of ATM (asynchronous transfer mode) networks is described. The performance of this algorithm is discussed in view of video-coder picture quality, exploitation of the statistical-multiplexing gain, traffic-control response time, hardware complexity, and application for policing nonvideo-services traffic. The main features of the proposal are summarized View full abstract»

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  • Cell-loss concealment in ATM video codecs

    Publication Year: 1993 , Page(s): 238 - 247
    Cited by:  Papers (86)  |  Patents (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1284 KB)  

    Methods for the interpolation of lost cells in asynchronous-transfer-mode (ATM) networks are studied. It is shown that use of motion-compensated previous frames gives the best results. The quality of the interpolated pictures improves if the motion vectors truly represent the actual motion in the scene. This is only possible with a two-layer coding scheme, where the motion vectors can be delivered to the decoder through the base-layer guaranteed channel. In derivation of the motion vectors at the encoder, use of uncoded input picture frames outperforms the conventional method of motion extraction from the previous coded pictures, despite the lower bit rate of the latter to the former. Depending on the quality of the base layer and the scene activity, the signal-to-noise ratio (SNR) in the cell-loss-interpolated areas can be improved by up to 10 dB 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