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Circuits and Systems for Video Technology, IEEE Transactions on

Issue 4 • Date Aug 1994

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Displaying Results 1 - 8 of 8
  • The effect of a loop filter on circulating noise in interframe video coders

    Page(s): 442 - 446
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB)  

    An examination of the distribution of signals within the prediction loop of an interframe video codec reveals that small random fluctuations caused by the quantizer build up over a period of time. This quantization noise circulates within the prediction loop causing a gradual decrease in the signal to noise ratio of the reconstructed sequence and an increase in the required data rate. In general, both of these effects can be nullified by the inclusion of a low pass loop filter View full abstract»

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  • Video bridging based on H.261 standard

    Page(s): 425 - 437
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1124 KB)  

    Multi-point ISDN videoconferencing with video bridging in network-based servers represents a viable new network service. The paper presents a detailed technical analysis of a continuous presence video bridge using the H.261 video coding standard. The authors first compare the pros and cons of coded domain versus pel domain video bridges. The architecture and the required operations of a coded domain bridge using H.261 are then investigated. They derive the bounds of the bridge delay and the required buffer size for the implementation of the bridge. The delay and the buffer occupancy of the video bridge depend on the order, complexity, and the bit-distribution of the input video sources. To investigate a typical case, the authors simulate the delay and the buffer occupancy of a video bridge. They also provide a heuristic method to estimate the delay in a typical case. Several techniques are discussed to minimize the bridge delay and the buffer size. Finally, they simulate intra slice coding and show that the delay and the buffer size can be reduced significantly using this technique View full abstract»

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  • Applications of 3-D LCR networks in the design of 3-D recursive filters for processing image sequences

    Page(s): 369 - 382
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (916 KB)  

    Applications of three-dimensional (3D) LCR prototype networks in the design of 3D recursive filters are reviewed and several types of new and useful 3D LCR prototype filters are proposed and classified. These 3D LCR prototype filters can be used to design 3D recursive filters for the processing of image sequences involving 3D spatio-temporal-domain linear-trajectory (LT) and planar-wave (PW) component signals. Among the new proposed filters, a 3D planar-rejection (PR) filter can be used to reject an undesired spatially-varying or spatially-static background LT component signal; a 3D planar-pass/planar-rejection (PP-PR) filter can be tuned to enhance a desired 3D LT component signal and, at the same time, reject an undesired 3D LT component signal. A technique for implementing the 3D filter transfer functions is proposed that employs 3D differential or 3D integral operators, leading to highly-parallel and modular 3D recursive filter structures that are efficient in computation. A simple design procedure is described and examples of image sequence processing are given View full abstract»

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  • A new three-step search algorithm for block motion estimation

    Page(s): 438 - 442
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    The three-step search (TSS) algorithm has been widely used as the motion estimation technique in some low bit-rate video compression applications, owing to its simplicity and effectiveness. However, TSS uses a uniformly allocated checking point pattern in its first step, which becomes inefficient for the estimation of small motions. A new three-step search (NTSS) algorithm is proposed in the paper. The features of NTSS are that it employs a center-biased checking point pattern in the first step, which is derived by making the search adaptive to the motion vector distribution, and a halfway-stop technique to reduce the computation cost. Simulation results show that, as compared to TSS, NTSS is much more robust, produces smaller motion compensation errors, and has a very compatible computational complexity View full abstract»

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  • Multiplexing of variable rate encoded streams

    Page(s): 417 - 424
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    Discusses the problem of multiplexing several variable rate encoded streams into a single stream. Moreover, in order to facilitate editing of the resulting stream it is required that data generated during the same time interval is multiplexed together. Particular emphasis is placed on controlling encoder rates and combining data in such a way as to avoid overflow and underflow of buffers at encoder and decoder. Applications include satellite or cable transmission of a fixed number of different video channels, multimedia presentations with multiple video streams, and video on demand View full abstract»

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  • Parallel architectures for 3-step hierarchical search block-matching algorithm

    Page(s): 407 - 416
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    The paper describes fully pipelined parallel architectures for the 3-step hierarchical search block-matching algorithm, a fast motion estimation algorithm for video coding. The advantage of this algorithm was completely utilized by use of intelligent data arrangement and memory configuration. Techniques for reducing interconnections and external memory accesses were also developed. Because of their low costs, high speeds, and low memory bandwidth requirements, the proposed 3-PE, 9-PE, and 27-PE architectures provide efficient solutions for real-time motion estimations required by video applications of various data rates, from low bit-rate video to HDTV systems View full abstract»

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  • Minimal error drift in frequency scalability for motion-compensated DCT coding

    Page(s): 392 - 406, 447-8, 499
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    The authors mathematically analyze the drift of low-resolution images obtained from a smaller IDCT of a subset of the DCT coefficients of the full-resolution images in motion-compensated hybrid predictive/DCT coding such as MPEG-2, which allows for frequency scalability. Using this mathematical structure, they derive a low-resolution decoder that has the theoretically minimum possible drift, and propose techniques for implementation that produce substantial improvement in real sequences. The minimum drift can also be used as a milestone, to be compared with other techniques of drift reduction (of worse performance but lower complexity). For the case where leakage is used to reduce the drift, the authors determine a minimum-energy non-uniform DCT-domain leakage matrix which is no more complex than uniform leakage, but gives a substantial improvement. Finally, they note that DCT-based pyramidal coding is essentially the same as the drift case, and thus they use the same mathematical structure to derive the theoretically-best upward predictor in pyramidal coding View full abstract»

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  • A study of vector transform coding of subband-decomposed images

    Page(s): 383 - 391
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    Studies vector transform coding (VTC), a new image coding scheme, on subband-decomposed images. It is shown that vector transformation (VT) reduces the inter-vector correlation, although not as much as the discrete cosine transform (DCT). However, it is also shown that VT preserves the intra-vector correlation much better than the DCT so that vector quantization (VQ) in the VT domain can be made more efficient. VTC of subband-decomposed images introduces another dimension of adaptivity, in which coding parameters, bit allocation, and VQ codebooks can be adapted to each level of the subband pyramid as well as to each vector in the VT domain. The new subband/VTC scheme is compared with VQ of original images, VQ of subband-decomposed images, DCT-based transform coding, and subband/DCT/VQ schemes. Simulation results indicate that the new scheme achieves 1 to 3dB improvement over the other schemes in terms of peak signal-to-noise ratio. This improvement is also supported by subjective evaluations 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