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Lecturer: Prof. Xinhua Zhuang CECS & EE Departments University of Missouri Columbia, MO 65211

Multimedia Communications 1. Lecturer: Prof. Xinhua Zhuang CECS & EE Departments University of Missouri Columbia, MO 65211.

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Lecturer: Prof. Xinhua Zhuang CECS & EE Departments University of Missouri Columbia, MO 65211

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  1. Multimedia Communications 1 • Lecturer: Prof. Xinhua Zhuang • CECS & EE Departments • University of Missouri • Columbia, MO 65211

  2. The Multimedia Experience 1 • Daily Newspaper • TV Program • Video-on-demand • Video Animation • Virtual Meeting Room • Distance Learning • Virtual Library • Living Books

  3. Multimedia 1 • including or involving the use of several media of communication, entertainment, or expression

  4. Multimedia vs. Multiple Media 1 • Multiple Media: unique delivery mechanism, unique repository or mailbox • electronic mail • voice mail • data files • Multimedia: single repository • messages with integrated text, sound, images, video, data files, handwriting • single access mechanism handling all media

  5. Multimedia Communications 1 • basic currency of communications switches from narrowband voice telephony to seamlessly integrated, high quality, broad-band transmission of multimedia signals • basic access method switches from wireline connections to combinations of wired and wireless (copper cable, ber, cell sites, satellite, and electrical power lines) • basic mode of communications expands from people-to-people communications to include people-to-machine communications

  6. Driving Forces in Multimedia Communications 1 • evolution of communications and data networks into modern POTS (plain old telephone service) and PACKET (a data unit belonging to level 3 of the ISO (International Standards Organization) reference model) networks, and further into an integrated structure • increasing availability of almost unlimited bandwidth on demand in both the office and the home, and eventually on road, due to proliferation of high speed data modems, cable modems, hybrid fiber-coax systems, and fixed wireless access systems • availability of ubiquitous (anywhere, anytime) access to network via LANs, and wireline and wireless networks

  7. Driving Forces in Multimedia Communications 1 • ever increasing amount of memory and computing power brought to bear on virtually any communications and computing systems • proliferation of smart terminals such as sophisticated screen phones, digital telephones, multimedia PCs natively handling a wide range of text, image, audio, and video signals • digitization of virtually all devices such as cameras, video capture devices, handwriting terminals, sound capture devices • standards for interconnections and communications between all devices attached to the network

  8. Where are we Today? 1

  9. Where are we Today? 1 • POTS: good for narrowband voice trac • PACKET: good for data trac • Services are separate for POTS and PACKET Networks • Control is separate for POTS and PACKET Networks

  10. Tomorrow's Network 1 • intelligence inside network • intelligence at the desktop • intelligence at the terminal • ubiquitous services • works with all types of access devices such as telephones, PC's

  11. Technology Aspects of MM Systems 1 • compression and coding of multimedia signals; standards • organizing, storing, and retrieving multimedia signals; streaming (real time transmission of multimedia signals), layering, QoS (Quality of Service) issues • accessing multimedia signals by matching the user to the machine; GUI (graphical user interface), SLI (spoken language interface), media conversion, agents • searching multimedia archives and databases based on machine intelligence; text, image, speech • browsing multimedia archives and documents based on human intelligence; text, image, audio, video

  12. Illustrative Multimedia Systems 1 • teleconferencing systems which integrate voice, video, application sharing, data sharing • FusionNet service which integrates the POTS and PACKET networks by exploiting Internet search and VCR-like features for viewing video, with POTS access to video content • CYBRARY digital virtual library which aims to provide a digital library experience which is better than being there live • Pictorial Transcripts system which provides a content-based sampled representation of video over the Internet

  13. Technology Assumptions 1 • multimedia processing is a lot more than compression and coding • multimedia applications need to be standard-based • handling (delivery, display) of multimedia signals is crucial • user interface is critical to usability of most applications • multimedia experience is shared between people and machines

  14. Image Coding Principles 1 • spatial redundancy • repeated patterns • image correlations in space • spectral correlations • temporal redundancy • repeated objects in video sequence • predictable moves of objects • take advantage of human visual system • perceptual masking of intensity, color, texture, time sequence

  15. Image Coders: FAX 1 • Group 3 FAX: simple 1-D search • Group 4 FAX: simple 2-D search • JBIG-1: prediction based on local neighborhood • JBIG-2: soft pattern matching on segmented regions

  16. Image Coders: Continuous Tone 1 • JPEG • block-based DCT • psychophysically based scalar quantization • entropy coding • JPEG-2000 • modern architecture and standard • downloadable software • handles a broad range of conditions

  17. JPEG Performance 1 • 8:1 Indistinguishable • 10.7:1 Excellent • 21.4:1 Very Good • 32:1 Good • 64:1 Fair

  18. Video Coders 1 • H.261, H.262, H.263: motion compensated coder for interframe coding • MPEG-1: multimedia standard with specifications for coding, compression and transmission of audio, video, and data streams in a series of packets • MPEG-2: multimedia standard with capability of compressing, coding and transmitting high quality, multi-channel multimedia signals over broadband networks • MPEG-4: object-based approach to multimedia with independent coding of objects, interactive compression of objects, ability to integrate synthetic and natural objects • MPEG-7: searching, indexing, authentication of large databases

  19. Video Coding 1 • video conferencing: H.261 for ISDN, H.263 for POTS • movie storage on CDROM: MPEG-1, 1.2 Mb/s for video, 256 kb/s for audio • broadcast video on DVD (digital video disk): MPEG-2, 2-15 Mb/s for video/audio • low bit rate telephony over POTS network: MPEG-4, 10 kb/s for video, 5.3 kb/s for voice • HDTV with 15-400 Mb/s for video

  20. Searching of Multimedia Documents 1 • text-based indexing • structured (field-based) in databases  SQL (Structured Query Language) queries • unstructured or natural language text  full text search • uses inverted index for each word; records document and location • can do partial matches • can find word variants • information extraction from documents • speech indexing • full recognition of text (error prone) • event detection (word spotting) • speaker identification used to align speech and text

  21. Searching of Multimedia Documents 1 • audio indexing • start and end of speech • musical signatures for instruments • singing voice • image indexing • classification by color and brightness histograms, texture, extracted shapes • hand-drawn description of image content • figure captions, textual description of image content • video indexing

  22. Browsing of Multimedia Documents 1 • text-based browsing • table of contents, index, skimming • image-based browsing • find image of interest, examine associated text • scene-based browsing • find place in video for full search or editing • video skimming browsing • high speed playback • audio skimming browsing • high speed playback

  23. Multimedia Conferencing 1

  24. FusionNet Concept 1 • High quality audio/video over the network • Internet provides vast development and information resources for browsing, searching • POTS provides guaranteed QoS transmission with security and billing • Client needs to gain access to both the Internet and POTS • Server needs to gain access to both the Internet and POTS

  25. The CYBRARY Project at AT&T 1 • virtual presence in a library • see documents in their original form on any screen connected to the Internet • create a new standard for document image compression (DJVU) geared towards screen display rather than printing • efficient document compression allows fast page flipping and browsing • OCR allows full text search and indexing

  26. Pictorial Transcripts 1 • Fully automatic generation of multimedia document from full motion video source material • Enables broadcasters to go on-line with no additional manual effort • Generate content for network-based hosting service

  27. Summary 1 • multimedia is more than multiple media • multimedia merges computing, communications, and information sciences • multimedia depends on networking, computation, and memory • multimedia depends on compression, standards, user interfaces, • searching, and browsing • multimedia involves integration, systems, testing, and conformance testing

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