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Multimedia Communications 1

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University of Missouri. Columbia, MO 65211. 2. The Multimedia Experience. 1. Daily Newspaper. TV Program. Video-on-demand. Video Animation. Virtual Meeting Room ... – PowerPoint PPT presentation

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Title: Multimedia Communications 1


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
  • 81 Indistinguishable
  • 10.71 Excellent
  • 21.41 Very Good
  • 321 Good
  • 641 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 ATT

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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