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Multimedia Communications

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

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The Multimedia Experience

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Daily Newspaper TV Program Video-on-demand Video Animation Virtual Meeting Room Distance Learning Virtual Library Living Books

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Multimedia

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including or involving the use of several media of communication, entertainment, or expression

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Multimedia vs. Multiple Media

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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

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Multimedia Communications

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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

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Driving Forces in Multimedia Communications

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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

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Driving Forces in Multimedia Communications

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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

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Where are we Today?

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Where are we Today?

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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

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Tomorrow's Network

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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

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Technology Aspects of MM Systems

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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

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Illustrative Multimedia Systems

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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

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Technology Assumptions

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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

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Image Coding Principles

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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

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Image Coders: FAX

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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

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Image Coders: Continuous Tone

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JPEG block-based DCT psychophysically based scalar quantization entropy coding

JPEG-2000 modern architecture and standard downloadable software handles a broad range of conditions

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JPEG Performance

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8:1 Indistinguishable 10.7:1 Excellent 21.4:1 Very Good 32:1 Good 64:1 Fair

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Video Coders

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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

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Video Coding

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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

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Searching of Multimedia Documents

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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

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Searching of Multimedia Documents

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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

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Browsing of Multimedia Documents

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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

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Multimedia Conferencing

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FusionNet Concept

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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

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The CYBRARY Project at AT&T

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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

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Pictorial Transcripts

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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

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Summary

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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