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2nd International conference on Intelligent processing and Manufacturing of Materials, IPMM 1999

作者： Park, Gwang Hoon Park, Jae Hyung Lee, Yoon Jin Department of Computer Science Yonsei University 234 Maji Heungup Wonju Kwangwon Korea Republic of

ISBN: (纸本)0780354893

• MPEG-4 codec can multiplex a set of independently-coded, arbitrarily-shaped video objects and transmit it through cither fixed or variable rate channels such as internet, wireless or sat ellite communications. • Quality control algorithms should support the encoding process of the visual objects to obtai n and maintain best picture quality under the constraints of the quality requirements and ch annel environments. • This paper focuses on the design of the intelligent rate control algorithm via introducing glob al rate distortion (KD) model constructed by quadratic neural network, by evaluating data-d riven pattern analysis rather than rate-distortion mathematical models. • Proposed global RD model is very useful in case the characteristics of the video sequences ar e rapidly varying. • The regression based mathematical model may not support rapidly changing environments, because it requires the time to stabilize to generate appropriate Q steps. • Intelligent rate control based on the global RD model can generate appropriate Q steps imm ediately in feedforward manner. • The performances of the proposed algorithm are superior than those of the MPFG-4 Vm5+ r ate control based on the regression process, in comparison with the average hits per frame to satisfy the channel constraints, encoded peak Signal-to-Noise Ratio (PSNR), and the number of frame skips. © 1999 IEEE.

关键词： image coding

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Alpha-EEG indicated kansei evaluation on visual image granularity

Alpha-EEG indicated kansei evaluation on visual image granul...

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IEEE International conference on Systems, Man and Cybernetics

作者： T. Maekawa R. Nakatsu E. Nishina Y. Fuwamoto T. Oohashi ATR Media Integration and Communications Research Laboratories Soraku-gun Kyoto Japan National Institute of Multimedia Education Chiba Chiba Japan Yokkaichi University Yokkaichi Mie Japan ATR Human Information Processing Research Laboratories Soraku-gun Kyoto Japan

We have investigated human kansei (emotional) reactions to differences in the visual image granularity of still images based on electroencephalographic alpha activity (alpha-EEG). The results suggest that (1) finer visual images decrease the brain's load, and (2) humans may be sensitive to visual image granularity beyond their visual acuity.

关键词： Humans History Psychology Information processing Laboratories Digital multimedia broadcasting Multimedia computing Multimedia communication Communication systems image resolution

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Transporting H.320 video conference traffic to the internet

Transporting H.320 video conference traffic to the internet

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Proceedings of the 1999 visual communications and image processing

作者： Ku, Chin-Fu Ko, Hung-Yu Lin, Jeng-Wei Pan, Yu-Chun Ho, Jan-Ming Chen, Meng-Chang Ko, Ming-Tat Chen, Sao-Jie Academia Sinica Taipei Taiwan

Although H.320 is one of the most popular ITU-T standard for video conference systems, H.323 is receiving wide acceptance in the internet society. In this paper, we study the problem of transporting video conference traffic to and from the internet. Some characteristics of the problem are as follows. For example, H.323 video stream is VBR while H.320 video stream is CBR;H.323 is byte-oriented while H.320 is bit-oriented;audio and video packets are transmitted independently in H.323 while they are multiplexed together in H.320;the probability of packet loss in a H.323 network is much higher than in a H.320 ISDN circuit switching network. In this paper, we present our designs and some preliminary experimental results in dealing with these issues.

关键词： Video conferencing

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Error concealment techniques for H.263 video transmission

IEEE Pacific RIM Conference on Communications, Computers, an...

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IEEE Pacific RIM conference on communications, Computers, and Signal processing - Proceedings 1999年 276-279页

作者： Kwon, David Driessen, Peter Univ of Victoria Canada

Error resilient video transmission over such unreliable channels as wireless and Internet has became an important research issue especially with the increasing interests in the mobile multimedia communication over the next generation wideband networks. Error detection and concealment techniques, which are applicable to such block-based motion estimation video coders as H.263[3] and MPEG, are proposed. An error concealment scheme by postprocessing to hide visual artifacts and residual errors is utilized at the decoder. Those techniques recovering the damaged areas based on characteristics of image and video signals are implemented using both spatial interpolation and temporal motion estimation. Based on the international standard H.263, experimental results including video transmission characteristics over noisy channels are presented for a bit rate of 9.6kbps and QCIF resolution. It is shown that the proposed error concealment technique by post-processing enhances the decoder performance in terms of the reconstructed image quality represented by PSNR and doesn't require sacrifice of system overhead.

关键词： image communication systems

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Flat multi-scalable coding for failure-free video transmission

Flat multi-scalable coding for failure-free video transmissi...

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IEEE International conference on image processing

作者： R. Kawada S. Matsumoto Visual Communications Laboratory KDD Research and Development Laboratories Inc. Kamifukuoka Saitama Japan

The conventional full-redundant duplicate transmission scheme, which is often adopted in video transmission that requires high reliability such as contribution and primary distribution, has a drawback in that the efficiency of utilization of transmission links is low. In order to improve this, it would be effective to realize "flat multi-scalable video transmission", in which the picture can be reconstructed by using any single channel, while combining more than one channel leads to the reconstruction of the picture with even higher quality. In this paper, for this purpose, the authors propose a "complementary sampling method". In this method, the improvement in picture quality is achieved by cancelling out the coding noise which is included in more than one channel. Moreover, it is shown that in this scheme, the objective assessment of picture quality can be performed based only on the received pictures. The authors hope that this study will help to construct a visual communication system with high efficiency and high reliability.

关键词： Streaming media visual communication Laboratories Sampling methods Master-slave Research and development Multimedia communication Broadcasting Redundancy Computer simulation

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Texture featuring and indexing using matching pursuit in Radon space

Texture featuring and indexing using matching pursuit in Rad...

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IEEE International conference on image processing

作者： Yong Man Ro Kiwon Yoo Multimedia Communication Group Information and Communications University Taejon South Korea Multimedia Commun. Group ICU Inf. & Commun. Univ. Taejon South Korea

ISBN: (纸本)0780354672

The matching pursuit algorithm in Radon space to achieve texture feature extracting is presented. The dictionary for matching pursuit is designed according to the human visual system (HVS). Since the matching pursuit is performed in Radon space, featuring the texture is more suitable to HVS behavior. Computer simulation and experimental results are shown to demonstrate the proposed method is outperformed to retrieve the texture.

关键词： Indexing Matching pursuit algorithms Multimedia communication Pursuit algorithms image storage image retrieval Frequency domain analysis Feature extraction Dictionaries Algorithm design and analysis

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A feedback channel based error compensation method for mobile video communications using H.253 standard

A feedback channel based error compensation method for mobil...

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IEEE International conference on image processing

作者： Byung Sun Choi Soo Il Chae Jong Beom Ra Department of Electrical Engineering Korea Advanced Institute of Science and Technology Taejon South Korea

ISBN: (纸本)0780354672

This study aims at finding an efficient compensation method of transmission errors in low bit-rate mobile communications using the H.263 video codec. For this aim, we suggest a novel error compensation method in the encoder (or transmitter), that can remove visual quality degradation due to spatio temporal error propagation by utilizing a feedback channel. In the proposed method, a corrupted-group of blocks (GOB) is concealed to avoid annoying artifacts due to the bit-error, and the GOB and its corresponding frame number are reported to the encoder via the feedback channel. Then, the encoder evaluates the negative acknowledgments and reconstructs the spatial and temporal error propagation by using a novel fast redecoding algorithm. The proposed error compensation method is compared with the two existing ones: the reference picture selection method and the error tracking method. Experimental results show that the proposed method is superior to the existing ones in many aspects.

关键词： Feedback Error compensation Mobile communication Decoding Video compression Degradation Video coding image coding Transmitters image reconstruction

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Integrated shot boundary detection using object-based technique

Integrated shot boundary detection using object-based techni...

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IEEE International conference on image processing

作者： Wei Jyh Heng K.N. Ngan Visual Communications Research Group Department of Electrical and Electronics Engineering University of Western Australia Nedlands WA Australia

Shot boundary detection is a technique used in the first stage of video parsing, whereby shots are extracted before objects are segmented and indexed. Most traditional techniques detect transitions by testing for the feature differences between frames, and tend to fail under long transition with large disturbance. This problem is solved in this paper by considering shot boundary from a different perspective and treating transitions as periods with temporal object discontinuity. A novel concept known as object-based shot boundary detection, which utilises frame lifetime for detection, is introduced. This technique is superior to traditional techniques as it is transition length independent disturbance resistant, transition type independent and does not need a trial-and-error threshold. Object-based detection logically becomes a preferable technique to be used in fully automatic shot extraction systems for the upcoming MPEG-7 platform.

关键词： Gunshot detection systems Object detection Layout Testing Motion detection visual communication Video compression Standards development Decoding Discrete cosine transforms

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Gaussian modeling for channel errors diagnosis in image transmission

Gaussian modeling for channel errors diagnosis in image tran...

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International conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： F. Labeau L. Vandendorpe B. Macq Remote Sensing Laboratory UCL Communications Louvain-la-Neuve Belgium

In this paper we propose an original study of the reconstruction of subband compressed images impaired by channel transmission errors. The method proceeds in two steps:first a detection scheme is applied to determine which coefficients of the subband decomposition have been affected by transmission, and then an estimation step tries to evaluate the erroneous coefficients. In our model, subband coefficients are considered to be drawn from jointly Gaussian random processes. Based on this assumption, conditional statistics can be computed which enable to test the likelihood of a given set of received coefficients with respect to the rest of the image. The detection and estimation processes are derived from these statistics. The method is validated through simulation and visual results are provided. The drawbacks of the method are outlined and explained through the discrepancies between the Gaussian assumption and real world images, namely around image edges.

关键词： image communication image reconstruction Statistics Filters Computational modeling image edge detection image restoration Pixel Redundancy Error analysis

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A figure extraction method based on the color and texture contrasts of regions

A figure extraction method based on the color and texture co...

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International conference on image Analysis and processing

作者： S. Tanaka Y. Iwadate S. Inokuchi ATR Media Integration and Communications Research Laboratories Soraku-gun Kyoto Japan Department of Systems and Human Science Osaka University Toyonaka Osaka Japan

Detecting interesting regions from pictures has become important in order to reduce the computational complexity associated with such time-consuming processes as object recognition. In this paper we assume that figure-ground segmentation of a picture is necessary as the first step towards evaluating the attractiveness of regions. In vision research, it has been found that the V4 cortex in the visual system contributes to figure-ground selectivity. By utilizing this finding, we propose a method for extracting figure regions from a picture based on the color and texture contrasts of regions. This method discriminates regions previously segmented from a picture into figure regions and ground regions by a discrimination function defined with contrast parameters. The contrast parameters include the color difference and the texture difference between a region and its surroundings, as well as the focus of the region. A discrimination function is constructed based on the characteristics of the extracted figures and ground obtained in our experiments. In other experiments on evaluating the accuracy of the proposed method, figure regions selected by human subjects are extracted by the method at the rate of 80% accuracy.

关键词： Humans Object detection Computational complexity Focusing Eyes Quality assessment Filters Cities and towns visual system Object recognition

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