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Circuits and Systems for Video Technology, IEEE Transactions on

Issue 2 • Date Feb 2003

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Displaying Results 1 - 10 of 10
  • Maximizing user utility in video streaming applications

    Page(s): 141 - 148
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (482 KB) |  | HTML iconHTML  

    We study some of the design tradeoffs of video streaming systems in networks with QoS guarantees. We approach this problem by using a utility function to quantify the benefit a user derives from the quality of the received video sequence. We also consider the cost to the network user for streaming the video sequence. We have formulated this utility maximization problem as a joint constrained optimization problem where we maximize the difference between the utility and the network cost, subject to the constraint that the decoder buffer does not underflow. In this manner, we can find the optimal tradeoff between video quality and network cost. We present a deterministic dynamic programming approach for both the constant bit rate and renegotiated constant bit rate service classes. Experimental results demonstrate the benefits and the performance of the proposed approach. View full abstract»

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  • Fast algorithms for foveated video processing

    Page(s): 149 - 162
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1589 KB) |  | HTML iconHTML  

    This paper explores the problem of communicating high-quality, foveated video streams in real time. Foveated video exploits the nonuniform resolution of the human visual system by preferentially allocating bits according to the proximity to assumed visual fixation points, thus delivering perceptually high quality at greatly reduced bandwidths. Foveated video streams possess specific data density properties that can be exploited to enhance the efficiency of subsequent video processing. Here, we exploit these properties to construct several efficient foveated video processing algorithms: foveation filtering (local bandwidth reduction), motion estimation, motion compensation, video rate control, and video postprocessing. Our approach leads to enhanced computational efficiency by interpreting nonuniform-density foveated images on the uniform domain and by using a foveation protocol between the encoder and the decoder. View full abstract»

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  • Constant quality constrained rate allocation for FGS-coded video

    Page(s): 121 - 130
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (537 KB) |  | HTML iconHTML  

    This paper proposes an optimal rate-allocation scheme for fine-granular scalability (FGS) coded bitstreams that can achieve constant quality reconstruction of frames under a dynamic rate budget constraint. In doing so, we also aim to minimize the overall distortion at the same time. To achieve this, we propose a novel rate-distortion (R-D) labeling scheme to characterize the R-D relationship of the source coding process. Specifically, sets of R-D points are extracted during the encoding process and linear interpolation is used to estimate the actual R-D curve of the enhancement-layer signal. The extracted R-D information is then used by an enhancement-layer transcoder to determine the bits that should be allocated per frame. A sliding-window-based rate-allocation method is proposed to realize constant quality among frames. This scheme is first considered for a single FGS-coded source, then extended to operate on multiple sources. With the proposed scheme, the rate allocation can be performed in a single pass; hence, the complexity is quite low. Experimental results confirm the effectiveness of the proposed scheme under static and dynamic bandwidth conditions. View full abstract»

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  • Determination of efficient transmission scheme for video-on-demand (VoD) services

    Page(s): 188 - 192
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (348 KB) |  | HTML iconHTML  

    In providing video-on-demand services in multicast environment, a broadcasting technique like skyscraper is very efficient for serving a very popular video in terms of resource requirement. However, a multicasting method like patching will achieve better performance if the video is not popular enough. Since there may not be a clear distinction between very popular and popular videos, an analytical model is developed in this paper to select an appropriate delivery scheme for the videos according to both the popularity of videos and the customer reneging behavior. The result shows that not only is the overall bandwidth of the system minimized, but a preset quality of service is also provided for each customer when using our proposed scheme. View full abstract»

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  • A texture replacement method at the encoder for bit-rate reduction of compressed video

    Page(s): 163 - 175
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2040 KB)  

    We propose a method for texture replacement in video sequences. Our method, which is applied at the encoder side, consists of removal of texture from selected regions of the original frames, synthesis of new texture, and mapping of the new texture back onto the segmented regions. The texture removal stage employs highly effective color-based angular maps. The texture analysis and texture synthesis stages make use of steerable pyramids. The latter stage also employs constraints that are derived using a vocabulary and grammar for color pattern similarity evaluation that have been introduced previously. Because they have different characteristics than those of the original textures, the synthesized textures can be coded more effectively. Consequently and most importantly, significantly reduced bit rates of the compressed video sequences with the texture replaced are obtained as compared to those of the original sequences. Moreover, because the synthesized textures have similar perceptual characteristics to those of the original textures, the video sequences with the texture replaced are also visually similar to the original sequences. Even more, because it is performed at the encoder and it does not have any impact on the decoder, our texture replacement method is cost effective. We illustrate its performance and computational efficiency using movie sequences. View full abstract»

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  • Scalable video coding with managed drift

    Page(s): 131 - 140
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (887 KB) |  | HTML iconHTML  

    Traditional scalable video encoders sacrifice coding efficiency to reduce error propagation because they have avoided using enhancement-layer (EL) information to predict the base layer (BL) to prevent the error propagation termed "drift". Drift can produce very poor video quality if left unchecked. We propose a video coder with significantly better compression efficiency because it intentionally allows the drift produced by predicting the BL from the EL. Our drift management system balances the tradeoff between compression efficiency and error propagation. The proposed scalable coder uses a spatially adaptive procedure that optimally selects key encoder parameters: the quantizer and the prediction strategy. Our numerical results indicate the encoder is very powerful, and the selection procedure is effective. The video quality of our coder at low rates is only marginally worse than the drift-free case, while its overall compression efficiency is not much worse than a one-layer nonscalable encoder. View full abstract»

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  • Embedded color image coding using SPIHT with partially linked spatial orientation trees

    Page(s): 203 - 206
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (349 KB) |  | HTML iconHTML  

    This paper describes a variation of the set partitioning in hierarchical trees (SPIHT) scheme for color image coding. By using partially linked spatial orientation tree structures across different spectral planes, the new color-SPIHT scheme is able to embed both chrominance and luminance data in the coded bit stream. The performance is comparable to that of a SPIHT-based coding scheme but with significantly lower computational complexity. View full abstract»

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  • General-tree-structured vector quantizer for image progressive coding using the smooth side-match method

    Page(s): 193 - 202
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB) |  | HTML iconHTML  

    Several tree-structured vector quantizers have been proposed previously. However, owing to the fact that all trees used are fixed M-ary tree-structured, the training samples contained in each node must be artificially divided into a fixed number of clusters. This paper presents a general-tree-structured vector quantizer (GTSVQ) based on a genetic clustering algorithm that can divide the training samples contained in each node into more natural clusters. Also, the Huffman tree decoder is used to achieve the optimal bit rate after the construction of the general-tree-structured encoder. Progressive coding can be accomplished by giving a series of distortion or rate thresholds. Moreover, a smooth side-match method is presented to enhance the performance of coding quality according to the smoothness of the gray levels between neighboring blocks. The combination of the Huffman tree decoder and the smooth side-match method is proposed herein. Furthermore, the Lena image can be coded by GTSVQ with 0.198 bpp and 34.3 dB in peak signal-to-noise ratio. View full abstract»

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  • Error-resilient image coding (ERIC) with smart-IDCT error concealment technique for wireless multimedia transmission

    Page(s): 176 - 181
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1449 KB) |  | HTML iconHTML  

    The fields of multimedia and wireless communications have grown rapidly, leading to a great demand for an image coding scheme that has both compression and error-resilient capabilities. Because bandwidth is a valuable and limited resource, the compression technique is applied to wireless multimedia communication. However, strong data dependency will be created while the bit-rate reduction is achieved. Transmission errors always results in significant quality degradation. An error-resilient image coding for discrete cosine transform-based image compression is proposed. It can successfully prevent errors from propagating across image block boundaries with little overhead. Additionally, a novel post-processing error concealment scheme is presented to retain low-frequency information and discard suspicious high-frequency information. Low-resolution information, rather than total corruption, can be obtained during the image-decoding process. Because of low complexity and latency properties, it is very suitable for wireless mobile applications. Simulation results show that good image quality (PSNR=31.78dB) and a low fraction of corruptive blocks (less than 5%) can be achieved even when the bit error rate is 0.1%. View full abstract»

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  • Robust H.263+ video transmission using partial backward decodable bit stream (PBDBS)

    Page(s): 182 - 187
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (698 KB)  

    We propose a novel robust H.263+ video transmission scheme using a partial backward decodable bit stream (PBDBS), which reverses the bit stream of some coded macroblocks (MBs) so that these coded MBs can be decoded in a backward direction. Because of using variable-length coding (VLC), the baseline H.263+ coder will lose synchronization until the next resynchronization marker when errors occur in the coded bit stream. It is wasteful to discard all of the remaining coded MBs in a group of blocks (GOB). Our method is to alleviate this effect by reversing the bitstream that belongs to the coded second half row of MBs in a GOB. When a decoder loses resynchronization, it will search the next resynchronization marker and decode the bitstream backward. It can retrieve half row of MBs that are lost otherwise. This method combined with error concealment can greatly improve the transmitted image quality. Up to 2-dB luminance peak signal-to-noise ratio improvement can be found in our method compared with the baseline H.263+ coder. We also compare our PBDBS method with H.263++ Annex V using data partitioning and reversible VLC. Under lower encoder and decoder complexity, the PBDBS method obtains more pleasant results than Annex V, and it can be utilized in noisy channels such as wireless networks. 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