( )Engineering Information Abstracts Part I404

pressed-domain techniques remove the unnecessary decom-pression and recompression procedures, thus, they have theadvantages of reduced computational complexity and storagerequirements. Simulation results demonstrate that the pro-posed DCT-domain techniques can achieve a comparableperformance at a much lower computational complexity com-

Žpared to the spatial-domain techniques. In English Author.abstract 17 Refs. EI Order Number: 98024091005

Keywords: Image coding; Image compression; Image commu-nication systems; Computational complexity; Mathematicaltransformations; Standards; Computer simulation

Title: ERROR CONTROL FOR LOW BIT RATE CODINGTRANSMISSION

( )Author s : Huang, Hsiang-Cheh; Hang, Hsueh-MingSource: Proceedings of the IEEE International Symposium onConsumer Electronics, ISCE Proceedings of the 1997 IEEEInternational Symposium on Consumer Electronics, ISCE’97Dec 2-4 1997 Singapore. Sponsored by: IEEE Piscataway NJUSA. p 165-168 CODEN: 002828Corporate Source: Natl Chiao Tung Univ, Hsinchu, TaiwanPublication Year: 1997Abstract: Video compression is an indispensable element inmultimedia communications systems. We simulate the H.263video coder and pass the compressed data through a simulatedmobile communication channel. Preliminary results indicatethat the error control codes, such as BCH codes, are veryuseful for protecting the compressed data. In addition, theerror correcting capability of the lapped orthogonal transformŽ . Ž .LOT are also investigated. In English Author abstract 9Refs. EI Order Number: 98044152190Keywords: Image communication systems; Image coding;Image compression; Computer simulation; Communication

Ž .channels information theory ; Data compression; Error cor-Ž .rection; Codes symbols ; Mobile telecommunication systems;

Mathematical transformations; Standards; Interactive com-puter systems; Error compensation

Title: LOW-COMPLEXITY AND LOW-DELAY VIDEOTRANSCODING FOR COMPRESSED MPEG-2 BIT-STREAM

( )Author s : Kan, Kou-Sou; Fan, Kuo-Chin; Huang, Yin-HwaSource: Proceedings of the IEEE International Symposium onConsumer Electronics, ISCE Proceedings of the 1997 IEEEInternational Symposium on Consumer Electronics, ISCE’97Dec 2-4 1997 Singapore. Sponsored by: IEEE Piscataway NJUSA. p 99-102 CODEN: 002828Corporate Source: Natl Central Univ, Chung-Li, TaiwanPublication Year: 1997Abstract: In this paper, an extremely efficient MPEG-2 videotranscoding method is proposed, which has a low buffer re-quirement and results in low delay. Most importantly, theproposed method does not need the computational intensivemotion estimation. Simulation results demonstrate that theproposed approach results in very consistent video quality and

Žmaintains the buffer level effectively. In English Author.abstract 4 Refs. EI Order Number: 98044152173

Keywords: Image coding; Image compression; Image quality;Computer simulation; Standards

Title: NOVEL VIDEO CODING SCHEME WITH FRE-QUENCY DOMAIN-BASED CONDITIONAL FRAME RE-PLENISHMENT ALGORITHM

( )Author s : Zheng, Weiguo; Xiao, ZimeiSource: Trends in Information Systems Engineering and Wire-less Multimedia Communications, Proceedings of the 1997 1stInternational Conference on Information, Communications

Ž .and Signal Processing, ICICS. Part 1 of 3 Sep 9-12 1997 v 1Singapore. Sponsored by: IEEE Piscataway NJ USA. p 274-278CODEN: 002795Corporate Source: Zhongshan Univ, Guangzhou, ChinaPublication Year: 1997Abstract: The massive amounts of data caused by digital videorequire efficient compressing scheme, but current popularvideo coding schemes, such as H.26x, Motion JPEG andMPEG, have either high complexity or low efficiency. Thispaper proposed a real-time video coding scheme with a condi-tional frame replenishment algorithm based on frequencydomain, which utilizes the characteristics of Discrete Cosine

Ž .Transform DCT and perception of human vision. The DCTbased interframe replenishment algorithm can encode anddecode digital video fast and efficiently. Because of its lowcomputing complexity, the video codec based on this algo-rithm can be implemented with lower cost, and it can bereal-time realized by PC software too. It’s suitable for low costPC-based video phone, video conference system and other

Žvisual multimedia communication system. In English Author.abstract 4 Refs. EI Order Number: 98024091719

Keywords: Image coding; Image compression; Real time sys-tems; Computational complexity; Mathematical transforma-tions; Frequency domain analysis; Algorithms; Vision; Decod-ing; Computer software; Personal computers; Standards

Title: H.263 BASED VIDEO CODEC FOR REAL-TIME VI-SUAL COMMUNICATIONS OVER WIRELESS RADIONETWORKS

( )Author s : Bahl, Paramvir; Chlamtac, ImrichSource: Annual International Conference on Universal Perso-nal Communications - Record Proceedings of the 1997 IEEE6th International Conference on Universal Personal Commu-

Ž .nications, ICUPC’97. Part 2 of 2 Oct 12-16 1997 v 2 SanDiego, CA, USA. Sponsored by: IEEE Piscataway NJ USA. p773-779 CODEN: 85PGAMCorporate Source: Microsoft Corp, Redmond, WA, USAPublication Year: 1997Abstract: With the emergence of the International Telecom-

Ž .munication Union’s ITU H.263 video coding standard, real-time visual communications over low-bandwidth, low-error-rate wired telephone networks is now possible. Unfortunately,because of the nature of the algorithms employed within thiscompression standard and due to the inherent limitations ofthe radio environment, H.263 coded video performs poorly

( )Engineering Information Abstracts Part I 405

when employed over bandwidth-limited, error-prone wirelesschannels. In this paper we propose an intuitive, low-complex-ity, pre-compression scheme that improves the performance ofH.263 coded video over radio channels. In our scheme videoframes are spatially segmented into regions of different per-ceptual importance before being compressed independentlywith the H.263 encoder. This allows us to apply unequal errorprotection and prioritized transmission to achieve at least aminimum temporal resolution at the receiver. Additionally,with this technique, both spatial and temporal error propaga-tion is limited and through intra-frame statistical multiplexingthe reserved transmission bandwidth is utilized optimally.Simulation results demonstrate that in the presence of severeerror conditions and severe bandwidth constraints, our modi-fied H.263 video codec exhibits better error concealment,better temporal resolution, and better bandwidth utilizationproperties than the original H.263 video codec. In EnglishŽ .Author abstract 11 Refs.Keywords: Image coding; Image compression; Image commu-nication systems; Radio communication; Communication

Ž .channels information theory ; Image segmentation; Erroranalysis; Multiplexing; Bandwidth; Computer simulation; Con-straint theory; Standards; Real time systems

Title: COMPRESSING IMAGES FOR THE INTERNET( )Author s : Beretta, Giordano

Source: HP Laboratories Technical Report n 97-163 Dec1997. Hwelett Packard Lab Technical Publ Dept Palo Alto CAUSA. 11p CODEN: HLTREYPublication Year: 1997Abstract: The World Wide Web has rapidly become the hotnew mass communication medium. Content creators are usingsimilar design and layout styles as in printed magazines, i.e.,with many color images and graphics. The information istransmitted over plain telephone lines, where the speedrpricetrade-off is much more severe than in the case of printedmedia. The standard design approach is to use palletized colorand to limit as much as possible the number of colors used, sothat the images can be encoded with a small number of bits

Ž .per pixel using the Graphics Interchange Format GIF fileformat. The World Wide Web standards contemplate a sec-

Ž .ond data encoding method JPEG that allows color fidelitybut usually performs poorly on text, which is a critical elementof information communicated on this medium. We analyze thespatial compression of color images and describe a method-ology for using the JPEG method in a way that allows acompact representation while preserving full color fidelity. In

Ž .English Author abstract 11 Refs. EI Order Number:98024043333Keywords: Image compression; Wide area networks; Imagecommunication systems; Image coding; Color image process-ing; Color computer graphics; Telephone lines; Standards;Data structures

Title: VISUAL INFORMATION RETRIEVAL FROM LARGEDISTRIBUTED ONLINE REPOSITORIES

( )Author s : Chang, Shih-Fu; Smith, John R.; Beigi, Mandis;Benitez, Ana

Source: Communications of the ACM v 40 n 12 Dec 1997.ACM New York NY USA. p 63-71 ISSN: 0001-0782 CODEN:CACMA2Corporate Source: Columbia Univ, New York, NY, USAPublication Year: 1997Abstract: The potentials of search and retrieval from large,distributed, online visual information repositories is discussedand an Internet based system called WebSEEk and MetaSEEkis described. Visual information retrieval from these systemsrequire the following critical components: a meta-data repre-sentation standard; open content-based query protocols; ef-fective methods for summarizing visual information; furtherexploitation of query previewing techniques; exploration ofboth push and pull methods of progressive storage and re-trieval of visual information; improved functionalities of theimage and video representations; and methods of operatingdirectly on compressed visual information. In English 12 Refs.EI Order Number: 98014033677Keywords: Image communication systems; Information re-trieval systems; Wide area networks; Query languages; Onlinesystems; Digital image storage; Feature extraction; Interactivecomputer systems; Image compression; Standards; Onlinesearching; Abstracting; Distributed computer systems

Title: VRML GETS REAL THE MPEG-4 WAY( )Author s : Mulroy, Patrick

Ž .Source: IEE Colloquium Digest Proceedings of the 1997IEE Colloquium on Teleconferencing Futures Jun 17 1997 n121 London, UK. IEE Stevenage England. p 4r1-4r4 ISSN:0963-3308 CODEN: DCILDNCorporate Source: BT Lab, Ipswich, UKPublication Year: 1997Abstract: As a standards effort with wide industry application,

Ž .Moving Picture Expert Group-4 MPEG will make a signifi-cant impact on the multimedia world. MPEG-4 hopes to movemultimedia communication from its current buzzword stage tobeing a real service on everyone’s desktop. The integration

Ž .with the Virtual Reality Markup Language VRML world willadd another dimension to this work and will make provision ofenhanced telepresence and virtual meeting room technologyfar more likely in the near term. The hooks into the VRML2.0 specification are already being discussed jointly by theVRML and MPEG-4 systems groups, and the core technologyneeded to develop the audiovisual coding and composition isalready at an advanced stage. In English 7 Refs. EI OrderNumber: 98024080528Keywords: Teleconferencing; Interactive computer systems;Standards; Virtual reality; Speech synthesis

Title: EXTENSIONS TO NONLINEAR EDITING ENCOM-PASSING MPEG-2 4:2:2 PROFILE

( )Author s : Cornog, K.; Sporer, M.Source: Proceedings of the 1997 International BroadcastingConvention Sep 12-16 1997 n 447 Amsterdam, The Nether-lands. IEE Stevenage Engl. p 302-307 ISSN: 0537-9989CODEN: IECPB4