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作者： Hsieh, Jeff Yeu-Farn Stanford University

学位级别：Ph.D.

Low power signal processing is critical in portable imaging applications where power translates directly to more images, longer videos, or lighter batteries. Complimentary-metal-oxide-semiconductor (CMOS) imagers are capable of lower power due to its ability to integrate analog to-digital conversion and logic circuitry on-chip. This dissertation presents an effective architectural solution to integrated digital video (DV) video compression that achieves a processing power efficiency of 42 giga-operations-per-Watt and allows for 23 hours of continual operation of a wireless imager generating compressed color video at 25 frames/second, 720 x 576 pixels per frame, and using a 5 Watt-hour Li-ion battery. First, an array of 40 identical processing elements (PEs) is chosen to support the 3.2 giga-operations-per-second computational requirement by partitioning the sensor array into distinct regions each clocked at 80 mega-Hertz. The low clocking requirement allows individual PEs to operate at a supply voltage of l.2 Volts in a 0.18 micron CMOS process, which results in a power reduction by a factor of two. Second, a hierarchical memory architecture is implemented to reduce power and to sustain the data throughput required for real-time processing. The memory systems power is reduced by more than a factor of four through an efficient mapping of the storage and access requirements to different levels of the memory hierarchy. Two memory technologies, the embedded DRAM and the SRAM, are studied for this mapping to take advantage of their area and access characteristics. Finally, parallel PEs are well suited for image and video processing where high instruction-level parallelism (ILP) exists. A non-negligible portion of DV compression algorithms are characterized by low ILP, which complicates instruction issuing. This is solved by introducing a dual-streaming mechanism for controlling the processor array in which a second control stream is used to feed coefficients as well as t

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Efficient key-frame extraction and video analysis

Efficient key-frame extraction and video analysis

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International Conference on Information Technology: Coding and Computing (ITCC)

作者： J. Calic E. Izuierdo Multimedia and Vision Research Lab University of London UK Multimedia & Vision Res. Lab Queen Mary Univ. of London UK

Content-based video indexing and retrieval has its foundations in the analyses of the prime video temporal structures. Consequently, technologies for video segmentation and key-frame extraction have become crucial for the development of advanced digital video systems. Conventional algorithms for video partitioning and key-frame extraction are mainly implemented autonomously. By focusing the analysis on compressed video features, this paper introduces a real-time algorithm for scene change detection and key-frame extraction that generates frame difference metrics by analysing the statistics of the macro-block features extracted from an MPEG compressed stream. The key-frame extraction method is implemented using difference metrics in curve simplification by means of a discrete contour evolution algorithm. This approach resulted in a fast and robust algorithm. Results of computer simulations are reported.

关键词： video compression Change detection algorithms Partitioning algorithms Algorithm design and analysis Indexing Content based retrieval Layout Statistical analysis Feature extraction Transform coding

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视频转码技术回顾

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通信学报 2002年第8期23卷 72-80页

作者：肖友能薛向阳曾玮复旦大学计算机科学与工程系上海200433

随着各种视频压缩标准的制定及计算机硬件、网络技术的发展,视频信息的应用呈现出爆炸式的增长。为了适应用户终端的多样性及网络自身的传输特性,20世纪90年代后期,视频转码成为视频编码领域一个新的研究热点。本文从视频转码的应用、... 详细信息

随着各种视频压缩标准的制定及计算机硬件、网络技术的发展,视频信息的应用呈现出爆炸式的增长。为了适应用户终端的多样性及网络自身的传输特性,20世纪90年代后期,视频转码成为视频编码领域一个新的研究热点。本文从视频转码的应用、体系结构和关键技术三个方面,回顾近几年来在视频转码方面的研究进展。

关键词：视频转码技术回顾数字视频视频编码视频压缩

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基于PSTN的远程多媒体监控系统

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中国图象图形学报（A辑） 2001年第6期6卷 594-598页

作者：戴礼荣李枫王仁华中国科学技术大学电子工程与信息科学系合肥230027

基于 PSTN网的远程多媒体监控技术 ,其关键是针对监控应用要求 ,在保证一定的图象和语音质量的同时 ,对图象与语音以尽量高的压缩率进行压缩 ,以及对图象与语音压缩进行实时处理 ;在所介绍的基于 PSTN的远程多媒体监控系统中 ,图象和语... 详细信息

基于 PSTN网的远程多媒体监控技术 ,其关键是针对监控应用要求 ,在保证一定的图象和语音质量的同时 ,对图象与语音以尽量高的压缩率进行压缩 ,以及对图象与语音压缩进行实时处理 ;在所介绍的基于 PSTN的远程多媒体监控系统中 ,图象和语音压缩处理是采用 H.2 6 3和 G.732 .1协议 .首先介绍了该系统组成结构 ;然后在简要介绍基于 H.2 6 3和 G.732 .1协议的图象与语音压缩算法的基础上 ,进一步讨论了针对远程多媒体监控的应用要求 ,基于图象与语音压缩的若干考虑 ,着重讨论和介绍了该系统的关键组成部分 ,即多媒体远程监控终端机的设计与实现 ,提出了基于高速 DSP技术的图象与语音压缩实时处理的关键技术及所采取的措施。

关键词：图象压缩语音压缩数字信号处理器 PSTN 公众电话网远程多媒体监控系统结构

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A system for placing videotaped and digital lectures on-line

A system for placing videotaped and digital lectures on-line

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International Symposium on Intelligent Multimedia, video and Speech Processing

作者： M.N. Wallick N. da Vitoria Lobo M. Shah School of Electrical Engineering and Computer Science University of Central Florida Orlando FL USA

ISBN: (纸本)9628576623

The idea of distance education, or learning at home has become very popular in recent years. Most major Universities offer classes on-line, and several smaller institutes exclusively offer distance classes. The distance courses can be offered either by mail (videotapes and books) or over the Internet (Web pages). Web-based courses are limited by bandwidth restrictions. This makes complex, interactive presentation of information virtually impossible. videotapes are able to present complex information, however the production and distribution cost of videotapes makes the idea very prohibitive. This paper presents a system for compressing video lectures for Internet transmission, without losing classroom information. In addition, we present algorithms that improve the interactivity of the presentation by use of optical character recognition and speech recognition technologies.

关键词： Internet Distance learning Educational institutions Postal services Books Web pages Bandwidth Costs video compression Optical character recognition software

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Adaptive encoders: The new generation of MPEG-2 encoders

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SMPTE JOURNAL 2000年第4期109卷 287-294页

作者： Guillotel, P Thoreau, D Ruellou, P Bordes, P Chupeau, B Chevance, C Thompson Multimedia R&D F-35511 Cesson Sevigne France

Whereas current debate concerns more object-oriented technologies, such as the MPEG-4 standardization process, this paper adresses the state of the art of MPEG-2 technology. The MPEG-2 standard was adopted four years ago and is currently used for broadcasting digital television worldwide. Some comments and requirements from the first field trials require a new generation of MPEG-2 compression systems, and it was the objective of this paper to try to give some inputs for them. Whereas the first generations were mainly an optimization of the TM5 model with new motion estimators, new bit-rate control strategies and sometimes new mode selection algorithms, this new generation will be adaptive to the picture content and complexity. This adaptation concerns not only the input data (such as picture resolution, noise reduction) or the encoder itself(GOP structure, local adaptation, multipass encoding), but also the bandwidth (statistical multiplexing). From the results presented here, a 20 to 30% bit savings can be expected on average, and locally more than 50% (for special cases where the encoders fails, i.e,. noise, scene cuts, fading). After being in the cost and system software, the competition is now clearly on compression efficiency to add as many programs as possible into one single channel. The new techniques developed and introduced in this phase of optimization will certainly be exploited in future standards such as MPEG-4 or MPEG-7 where segmentation and scene characterization, respectively, will be key technologies.

关键词： video videotapes Key technology new technique Systems software ENCODER Self tuning state of the art field experimentation MPEG 4 Standard

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High efficiency image/video coding techniques

High efficiency image/video coding techniques

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作者： Shen, Guobin Hong Kong University of Science and Technology

学位级别：博士

During the past decade the living style of many people has changed quite a lot due to the rapid progresses in multimedia presentation and communications and the blooming of the Internet. As indispensable components of multimedia, image and video are capable of carrying huge amount of information. This makes it absolutely necessary to compress the image and video signals. In this thesis, we will present contributions in three different sub-areas of video and image compression namely, Vector Quantization (VQ), arbitrarily shaped Discrete Cosine Transform (DCT) and transcoder with arbitrarily sampling rate alternate. Vector quantization is theoretically attractive due to the results from rate-distortion theory. It does yield superior performance over scalar quantization schemes. Despite this, however, a big gap exists between the performance predicted by the theory and that which can actually be achieved. This is due to the failure to observe the two basic assumptions of rate-distortion theory, namely, that the block length can be infinitely large, and the source is stationary. In this thesis, two methods that can amend this big gap are presented. The two methods are dedicated to combating the invalidity of the two assumptions, respectively. A window-based fast search algorithm is proposed to speed up the VQ process. The MPEG-4 standard provides some key technologies that enable interactivity between the user and video objects. One of the prerequisite conditions is the ability to encode arbitrarily shaped video objects. Computationally complex shape-adaptive DCT algorithms have been proposed in the literature. An invention that can achieve shape-adaptivity via padding and regular base-N DCT (N is a power of 2) is presented in this thesis work. The biggest benefit is that many available DCT chipsets and fast algorithms can be used directly to handle arbitrary shapes. A rate-optimization technique is proposed in order to further improve the coding performance. More and m

关键词： Electrical and Electronic Engineering Shen, Guobin Image processing digital techniques digital video video compression Coding theory MPEG (video coding standard)

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Low bitrate audio coding - state-of-the-art, challenges and future directions

Low bitrate audio coding - state-of-the-art, challenges and ...

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International Conference on Communication Technology (ICCT)

作者： K. Brandenburg Tech. Hochschule Ilmenau Germany

Perceptual encoding of high-quality audio has found its way to many applications including digital radio, electronic music distribution (EMD) systems and portable audio devices. An overview on the basics of high-quality low-bitrate audio coding is followed by a look into currently widely used and newer, state-of-the-art coding systems like MP3 and MPEG-2 advanced audio coding (AAC). The rapid deployment of older (1992) technologies (like MP3) followed by the news of new and improved algorithms (like AAC) raises questions about future improvements. The paper analyses some candidates for such improvements and provides a view of some current research activities.

关键词： Bit rate Audio coding Encoding Decoding Filter bank digital audio broadcasting digital video broadcasting digital audio players Audio compression Standardization

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Low bitrate audio coding-state-of-the-art, challenges and future directions

Low bitrate audio coding-state-of-the-art, challenges and fu...

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International Conference on Signal Processing Proceedings (ICSP)

作者： K. Brandenburg Fraunhofer IIS Arbeitsgruppe Elektronische Medientechnologie Ilmenau Technical University Ilmenau Germany

Perceptual encoding of high quality audio has found its way to many applications including digital radio, electronic music distribution (EMD) systems and portable audio devices. An overview on the basics of high quality low bitrate audio coding is followed by a look into currently widely used and newer, state-of-the-art coding systems like MP3 and MPEG-2 Advanced Audio Coding (AAC). The rapid deployment of older (1992) technologies (like MP3) followed by the news of new and improved algorithms (like AAC) raises the question about future improvements. The paper analyses some candidates for such improvements and provide a view of some current research activities.

关键词： Bit rate Audio coding Encoding Decoding Filter bank digital audio broadcasting digital video broadcasting digital audio players Audio compression Standardization

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video on the Internet: An introduction to the digital encoding, compression, and transmission of moving image data

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JOURNAL OF STRUCTURAL BIOLOGY 1999年第2-3期125卷 133-155页

作者： Boudier, T Shotton, DM Univ Oxford Dept Zool Oxford OX1 3PS England

In this paper, we seek to provide an introduction to the fast-moving field of digital video on the Internet, from the viewpoint of the biological microscopist who might wish to store or access videos, for instance in image databases such as the BioImage Database (http://***),We describe and evaluate the principal methods used for encoding and compressing moving image data for digital storage and transmission over the Internet, which involve compromises between compression efficiency and retention of image fidelity, and describe the existing alternate software technologies for downloading or streaming compressed digitized videos using a Web browser. We report the results of experiments on video microscopy recordings and three-dimensional confocal animations of biological specimens to evaluate the compression efficiencies of the principal video compression-decompression algorithms (codecs) and to document the artefacts associated with each of them. Because MPEG-1 gives very high compression while yet retaining reasonable image quality, these studies lead us to recommend that video databases should store both a high-resolution original version of each video, ideally either uncompressed or losslessly compressed, and a separate edited and highly compressed MPEG-1 preview version that can be rapidly downloaded for interactive viewing by the database user. (C) 1999 Academic Press.

关键词： BioImage compression codec database decompression digital image Internet JPEG

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