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Conference on digital video compression on Personal Computers: algorithms and technologies

作者： ROSER, M VILLEGAS, P TELEFON I&D E-28043 MADRIDSPAIN

ISBN: (纸本)0819414824

In this paper we present a work based on a coding algorithm for visual information that follows the International Standard ISO-IEC IS 11172, `Coding of Moving Pictures and Associated Audio for digital Storage Media up to about 1.5 Mbit/s', widely known as MPEG1. The main intention in the definition of the MPEG 1 standard was to provide a large degree of flexibility to be used in many different applications. The interest of this paper is to adapt the MPEG 1 scheme for low bitrate operation and optimize it for special situations, as for example, a talking head with low movement, which is a usual situation in videotelephony application. An adapted and compatible MPEG 1 scheme, previously developed, able to operate at px8 Kbit/s will be used in this work. Looking for a low complexity scheme and taking into account that the most expensive (from the point of view of consumed computer time) step in the scheme is the motion estimation process (almost 80% of the total computer time is spent on the ME), an improvement of the motion estimation module based on the use of a new search pattern is presented in this paper.

关键词： Diamond Motion estimation Computing systems Diamond patterning Visualization Information visualization Signal to noise ratio video coding Head Motion models

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ASIC IMPLEMENTATION OF RECURSIVE SCALED DISCRETE COSINE TRANSFORM ALGORITHM

ASIC IMPLEMENTATION OF RECURSIVE SCALED DISCRETE COSINE TRAN...

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Conference on digital video compression on Personal Computers: algorithms and technologies

作者： ON, BN NARASIMHAN, S HUANG, VKL NATL UNIV SINGAPORE INST MICROELECTRSINGAPORE 0511SINGAPORE

ISBN: (纸本)0819414824

A program to implement the Recursive Scaled Discrete Cosine Transform (DCT) algorithm as proposed by H. S. Hou has been undertaken at the Institute of Microelectronics. Implementation of the design was done using top-down design methodology with VHDL (VHSIC Hardware Description Language) for chip modeling. When the VHDL simulation has been satisfactorily completed, the design is synthesized into gates using a synthesis tool. The architecture of the design consists of two processing units together with a memory module for data storage and transpose. Each processing unit is composed of four pipelined stages which allow the internal clock to run at one-eighth (1/8) the speed of the pixel clock. Each stage operates on eight pixels in parallel. As the data flows through each stage, there are various adders and multipliers to transform them into the desired coefficients. The Scaled IDCT was implemented in a similar fashion with the adders and multipliers rearranged to perform the inverse DCT algorithm. The chip has been verified using Field Programmable Gate Array devices. The design is operational. The combination of fewer multiplications required and pipelined architecture give Hou's Recursive Scaled DCT good potential of achieving high performance at a low cost in using Very Large Scale Integration implementation.

关键词： Clocks Field programmable gate arrays Data storage video compression Microelectronics Very large scale integration video Computer architecture Data processing Image compression

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USING 4X4 DCTS AND MOVING 4X4 BLOCKS FOR SOFTWARE ONLY video DEcompression

USING 4X4 DCTS AND MOVING 4X4 BLOCKS FOR SOFTWARE ONLY VIDEO...

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Conference on digital video compression on Personal Computers: algorithms and technologies

作者： WILSON, R ACORN COMP LTD CAMBRIDGE CB4 4AEENGLAND

ISBN: (纸本)0819414824

4 X 4 inverse DCTs are computationally twice as efficient as 8 X 8 inverse DCTs. In addition they have less register pressure, making the implementation more efficient for most processors. This extra computational efficiency places more pressure on improving the other components of the video decompression system. This paper describes a coding scheme for the quantized components which has an efficient decompression algorithm. The implementation of the inverse DCT is examined in detail, including removing all multiplication operations and replacing them with single CPU cycle shift-and-add operations. The data flow through a complete 4 X 4 DCT is described such that the results of intermediate 1 X 4 DCTs are written to and read from memory as efficiently as possible. A set of quantizers for the 4 X 4 DCT are presented which allow the decompression process to use shift-and-add instead of multiply. Efficient DCTs by themselves are not enough: the paper discusses the effects of changing the search area (in particular to being non-square) and shows a coding scheme suitable for fast decompression. It also discusses how to organize the block matching and that good results can be obtained if some pixels are allowed to match worse than the nominal value.

关键词： Quantization video Computer programming Data conversion Data storage Image stacking Computing systems Compact discs video compression Eye

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METHOD FOR EXTRACTING CAMERA OPERATIONS TO DESCRIBE SUB-SCENES IN video SEQUENCES

METHOD FOR EXTRACTING CAMERA OPERATIONS TO DESCRIBE SUB-SCEN...

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Conference on digital video compression on Personal Computers: algorithms and technologies

作者： MAEDA, J IBM JAPAN LTD TOKYO RES LABKANAGAWA 242JAPAN

ISBN: (纸本)0819414824

Numerous attempts have been made to detect scene changes in video sequences and to treat scenes as units, to allow handling of very large amounts of video data. But less attention has been given to the structure of scenes themselves. In this study, we define a "sub-scene" as a structural component of a scene in terms of camera operations. In other words, sub-scenes are subsets of scenes, and consist of successive frames in which the movements of the contents are almost identical. The advantage of sub-dividing scenes into sub-scenes is that it gives added power to description of objects and motion information. Up to now, the mainstream of research on estimating camera operations has been frame-by-frame analysis: that is, most studies have evaluated the difference between the contents of two frames at a time, and estimated camera motions by analyzing such differences over a period. Though these techniques can estimate camera operations accurately, they are generally time-consuming and may be greatly affected by noise, such as unintentional movements of the cameraman's hands, in a few frames of a sequence. In order to describe sub-scenes, the estimation of camera operations need not be very accurate, but it must be resistant to noise. The technique proposed in this paper for extracting camera operations, which processes more than two frames at a time by using a two-dimensional spatio-temporal image, meets the above requirement. It is also faster than conventional frame-by-frame analysis. The results of experiments indicate that the technique is both feasible and useful. © 1994 SPIE. All rights reserved.

关键词： Cameras

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Audio data compression

Audio data compression

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Electronics Division Colloquium on Cascading Audio and video Data compression Systems

作者： Todd, Martin

The development of digital audio provided many opportunities for extensive applications of innovative audio processing technologies. Audio data compression was one novel technique that furnished solutions to audio storage and audio transmission. This new technique was based on mathematical algorithms that can be incorporated to digital signals. It minimizes the amount of data needed in signal representation while reducing fidelity loss due to the algorithm.

关键词： Data compression

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video conferencing and desktop video communications: An update

Video conferencing and desktop video communications: An upda...

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Photonics for Industrial Applications 1994

作者： Caspar, Joseph R. United Technologies Research Center East Hartford CT06108 United States

Although the visual aspect is important for communication between humans, the most common form of communications for separated humans, telephony, has no visual component. In recent years, advances in video compression have made video telephony possible from specialized rooms but, until recently, expensive and inconvenient. Decreasing costs and technical advances are now bringing video telephony into the office in both digital and analog form. video telephony, coupled with collaborative computing, now provides a more complete technical capability for office-To-office communications. The near future should make video telephony common and productive. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： video conferencing

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Multimedia authoring, development environments, and digital video editing

Multimedia authoring, development environments, and digital ...

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Photonics for Industrial Applications 1994

作者： Makedon, Fillia Matthews, James W. Owen, Charles B. Rebelsky, Samuel A. Dartmouth College Department of Computer Science Dartmouth Experimental Visualization Laboratory HanoverNH03755 United States

Multimedia systems integrate text, audio, video, graphics, and other media and allow them to be utilized in a combined and interactive manner. Using this exciting and rapidly developing technology, multimedia applications can provide extensive benefits in a variety of arenas, including research, education, medicine, and commerce. While there are many commercial multimedia development packages, the easy and fast creation of a useful, full-featured multimedia document is not yet a straightforward task. This paper addresses issues in the development of multimedia documents, ranging from user-interface tools that manipulate multimedia documents to multimedia communication technologies such as compression, digital video editing and information retrieval. It outlines the basic steps in the multimedia authoring process and some of the requirements that need to be met by multimedia development environments. It also presents the role of video, an essential component of multimedia systems and the role of programming in digital video editing. A model is described for remote access of distributed video. The paper concludes with a discussion of future research directions and new uses of multimedia documents. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： Multimedia systems

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digital video and speech transmission in existing land mobile radio networks

European transactions on telecommunications and related tech...

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European transactions on telecommunications and related technologies 1994年第6期5卷 705-718页

作者： Mann Pelz, R. Benthin, M. Kammeyer, K.-D. Robert Bosch Research Inst Communications Hildesheim Germany

The development of very low bit rate image compression algorithms renders the transmission of moving and still video with associated speech in a variety of existing and future narrowband telecommunication networks. Existing analog, narrowband (mobile) networks represent a potential field for the introduction of digital bearer services under utilization of the underlying system resources in a compatible manner. A broader variety of services in coexistence with existing analog services may be provided without new network planning. This paper presents corresponding techniques for video and speech transmission in the existing Nonpublic Land Mobile Network under application of commercially available radio telephones and an additional, external digital signal processing unit. Special attention is given to the choice of a digital modulation method under consideration of network constraints such as adjacent channel interference and linear distortions due to nonideal analog IF filters. In this context a modified maximum likelihood detector based on an equivalent linear model of the baseband transmission link is presented. For robust low bit rate video transmission a combined source-channel coding scheme with unequal error protection matched to the source and channel characteristics in case of the target mobile narrowband network is proposed.

关键词： Mobile radio systems

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video COMMUNICATIONS AND SERVICES IN THE COPPER LOOP

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IEEE COMMUNICATIONS MAGAZINE 1993年第1期31卷 62-68页

作者： HSING, TR CHEN, CT BELLISIO, JA BELLCORE VIDEO SYST & SIGNAL PROC RES DEPTMORRISTOWNNJ BELLCORE VIDEO SYST & SIGNAL PROC RES DEPTRED BANKNJ

There are several technologies available for providing access using the embedded copper loop plant. However, none of these technologies can provide a high-bit-rate digital transport capability (1.544 Mb/s) over the existing loop plant. The authors describe continuing advances in both VLSI implementation and signal processing algorithms that are making it possible to provide the high-bit-rate digital subscriber line (HDSL) for a repeaterless T1 capability within carrier serving areas (CSAs); asymmetric digital subscriber lines (ADSL) for a 1.5-Mb/s transport capability over the nonloaded copper loop plant; and the next-generation ADSL-II for a 3 to 4 Mb/s transmission rate over CSA ranges. It is argued that, coupled with advances in video compression techniques and recent standards activities in CCITT, these bit rates will allow local exchange carriers (LECs) to provide video communication and services using highly compressed digital video by allowing the LECs to use their existing embedded loop plant to enter the video market and establish a base of customers.< >

关键词： Copper Repeaters Telephony DSL Optical fiber subscriber loops video compression Signal processing Wiring Subscriber loops Marine vehicles

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HIGH-SPEED A/D AND D/A INTERFACE FOR PCS WITH APPLICATIONS IN IMAGE-PROCESSING

HIGH-SPEED A/D AND D/A INTERFACE FOR PCS WITH APPLICATIONS I...

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Conference on video Communications and PACS for Medical Applications

作者： VLAICU, A MECIU, E IACOB, S TECH UNIV CLUJ NAPOCA DEPT COMMUNR-3400 CLUJ NAPOCAROMANIA

ISBN: (纸本)0819412236

The paper is concerned with theoretical and practical problems related to real time acquisition and storage of standard PAL/SECAM images and also with developing fast software algorithms for digital image processing. A first section of the paper comprises the description of the block diagram of the PC plug-in conversion unit and a second one refers to practical image data compression and basic image processing algorithms.

关键词： Data conversion Image processing video Data compression Algorithm development Image compression Data storage digital image processing Image storage Software development

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