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Intro to Information Systems I

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Easy to create stuff this way, but harder to edit, and harder to keep smooth ... Raw audio files are very large, hence compression is important ... – PowerPoint PPT presentation

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Title: Intro to Information Systems I


1
Intro to Information Systems I
  • Multimedia and Communications
  • ISYS 101
  • Glenn Booker

2
Multimedia World
  • Multimedia presentations go beyond the vu-graph
    mode of presentation applications to blend
    graphics, animation, video, and sound
  • Metaphor becomes theater instead of a podium
    presentation
  • Many multimedia tools are designed for the Web

3
Interactivity
  • A major feature of multimedia presentations can
    be the use of interactive elements where the
    viewer chooses their path through the
    presentation instead of seeing a fixed series of
    events
  • Normal web pages achieve interactivity through
    hyperlinks

4
Multimedia Hardware
  • Basic input and output hardware for multimedia
    include a CD-ROM or DVD-ROM drive, sound card,
    and speakers (all now standard on personal
    computers)
  • Optional equipment includes a microphone,
    graphics tablet, digital camera, and a TV video
    adapter

5
Multimedia Hardware
  • Faster video cards and 3-5 speakers instead of
    just one or two (e.g. adding a subwoofer or going
    for surround sound or theater-grade THX sound)
    help too

6
Multimedia Uses
  • Multimedia is used increasingly for
  • Computer based training (CBT) or education (CBE)
  • Livening up reference materials (encyclopedias)
  • Creating stand-alone sales or information kiosks,
    playing a loop of information
  • Even art is starting to use multimedia

7
Big Files Need Compression
  • Multimedia takes a lot more disk space than text,
    so compression techniques are important
  • Algorithms are used to calculate how data can be
    compressed these algorithms are called codecs
    (for compression/ decompression)

8
Compression Types
  • Compression techniques can be lossless or lossy
  • Lossless techniques retain every bit of original
    data (literally!)
  • Lossy techniques sacrifice some low level data
    detail to produce higher levels of compression

9
Graphics Compression Formats
  • GIF (like gift without the t) allows a
    maximum of 256 colors (8-bit), uses lossless
    compression, and is often used for simpler Web
    graphics
  • JPEG allows up to 16.7 million colors (24-bit),
    is lossy, and often used for photos or other
    complex images on the Web

10
Graphics Compression Formats
  • PNG is a new format like GIF, but isnt
    proprietary (you have to pay royalties to be able
    to create GIF images)
  • Bitmap (BMP) is the Windows standard for
    primitive graphics is often without
    compression, so bitmaps are huge
  • A bitmap describes every pixels color

11
Graphics Software
  • Graphics software programs tend to fall into
    three types for working with a single image
  • Paint programs, which use bit-mapped or raster
    graphics
  • Drawing programs, which use vector graphics
  • Image editors, for modifying existing photos

12
Paint Programs
  • Paint programs are designed to create images at
    the pixel level
  • Easy to create stuff this way, but harder to
    edit, and harder to keep smooth
  • Examples Fractal Design Painter, Paint Shop Pro,
    Corel Painter

13
Drawing Programs
  • Drawing programs use vector graphics each line
    is described by a math formula
  • Draw and shape lines, then fill in colors and
    textures among them
  • Creates smoother images, which can be scaled to
    any size

14
Drawing Programs
  • Saves documents in EPS format, which some
    printers understand
  • But EPS isnt Web friendly
  • Examples Adobe Illustrator, Macromedia
    Freehand, CorelDRAW

15
Image Editors
  • Image editors are for manipulating existing
    pictures (e.g. photos)
  • Allow you to resize, crop, merge and add special
    effects to the images
  • Examples Adobe Photoshop and PhotoDeluxe

16
Moving Picture Software
  • Programs for working with moving pictures
    include
  • 3-D rendering programs, for adding 3-D effects to
    graphics (lighting, shadows, etc.)
  • Animation programs, for creating the illusion of
    moving pictures through graphics
  • Video editors, for creating and editing digital
    videos

17
3-D Rendering Programs
  • Rendering programs account for specific light
    sources, and determine shadows, transparency, and
    other effects
  • Used to require a supercomputer to do this
  • Ray tracing is one technique they use
  • Examples Renderman, AutoCAD, 3D Studio MAX

18
Animation Programs
  • Animation is based on presenting still images
    rapidly in succession
  • A movie uses 24 frames per second
  • Computer animation uses the same idea with GIF
    images
  • Some programs recognize background images versus
    those elements which move

19
Animation Programs
  • Examples Adobe LiveMotion, Macromedia Flash, and
    Softimage XSI
  • Some high end () programs combine animation
    with 3D rendering, such as Discreet combustion,
    Maya Complete, and Newtek Lightwave

20
Video Editors
  • Video editors take input from a digital video
    camera, and allow it to be rearranged, add sound,
    etc.
  • Examples Adobe Premiere

21
Video Formats
  • Videos are usually in one of three formats
  • MPEG is the standard for full motion video, such
    as DVDs
  • QuickTime is an Apple standard for high quality
    video and audio
  • AVI (formally Video for Windows) tend to be
    fairly low quality

22
Streaming Video
  • One way to get video across the Internet quickly
    is to use streaming video
  • A small bit of video is sent continuously to the
    viewer
  • Hence the viewer doesnt need to download the
    entire video before watching it
  • But the viewer also never has a copy of the video
    either

23
Audio Software
  • Audio software has improved to where most
    professional recording studios dont bother with
    magnetic tape for recording they use computers
    instead
  • Sound uses can range from simple background music
    to original compositions

24
Audio Formats
  • Audio is digitized at 44.1 kHz for CDs
  • Raw audio files are very large, hence compression
    is important
  • MP3 is the most common format, can be compressed
    up to 1/12th of original size
  • AU format is used on Sun workstations
  • WAV files are used in Windows, arent compressed

25
Audio Software
  • Musical instruments use MIDI language to speak to
    computers
  • Audio applications include
  • Notation programs to write music
  • Recording and editing programs
  • Mixers and synchronizers to coordinate many
    musical parts into one piece

26
Putting it all together
  • Authoring software is used for assembling
    multimedia presentations from all of its parts
    (sound, graphics, video, animation)
  • Uses a scripting language to coordinate
    activities
  • Example Macromedia Director

27
Virtual Environments
  • Massive improvements in multimedia have led to
    the concept of creating virtual environments
  • Hardware like head-mounted displays make it
    possible to present a realistic fake environment

28
Virtual Formats
  • VRML (Virtual Reality Modeling Language) is a
    front-runner in providing a virtual environment
    via the Internet
  • Used for games, training, and data visualization
  • One common game environment is the Multi-User
    Dungeon (MUD)

29
Telecommunications
  • Some aspects of computer networking depend on the
    existing telecommunications infrastructure
  • Most home users use analog telephone lines for
    their modem connection to the Internet
  • Telecom is moving from analog signals on copper
    wires to digital signals

30
Telecommunications
  • Analog wires can go up to T1 speed (1.5 Mb/s) or
    24 voice signals
  • Digital signals may be sent across fiber optic
    cables, or beamed using microwaves
  • Fiber optics can go up to T3 speed (43 Mb/s) or
    672 voice signals using pulses of light

31
Telecom Standards
  • Telecom standards are defined by the ITU, a
    branch of the United Nations
  • Telecom is a vital service for safety, so it is
    heavily regulated to ensure service to
    unprofitable regions
  • Private or leased lines can be used for
    communication too

32
Modems
  • Modems modulate and demodulate signals
  • That converts a digital signal to analog, and
    back again at the other end
  • Modem speeds evolved from 300 bits/sec (circa
    1970s) to the theoretical limit of 56,000 bps

33
Modem Standards
  • The current limit is defined by the V.90 standard
    (56 kbps)
  • Earlier standards were V.34 (28.8 kbps) and V.32
    (14.4 kbps)
  • Modems negotiate the fastest connection both
    sides can handle
  • Faxes can also be sent, generally at 9.6 kbps

34
Need for Speed
  • Bandwidth, or the speed at which data can be sent
    and received, is critical for emerging
    applications
  • Video conferencing needs 10 Mbps
  • High definition TV (HDTV) needs 11 Mbps
  • Broadband refers to digital telecom at speeds of
    1.5 Mbps and up (T1 or better)

35
Broadband Options
  • ISDN is the most common broadband service
  • Basic ISDN goes up to 128 kbps
  • Primary ISDN goes up to 1.5 Mbps (T1)
  • Broadband ISDN doesnt exist yet claims up to
    622 Mbps

36
Broadband Options
  • Digital Subscriber Lines (DSL) is still rare
  • Some versions are asymmetric (you can have much
    slower upload speed than download)
  • Range from 128 kbps to 9.1 Mbps speeds
  • Speed varies depending on how far you are from
    the provider
  • SONET is a future possibility range from 52 Mbps
    to 1 Gbps

37
Cable Modems
  • Cable modems use coaxial cable from your TV cable
    provider to feed Internet access
  • Cable bandwidth is shared among the users in the
    local area more users online means slower
    speeds for each user
  • Speed can range from 100 kbps to over 2000 kbps

38
Power Lines?
  • Internet connections can be passed over power
    lines too
  • Still experimental
  • Not likely to work in the US

39
Phone, TV, and Internet Merge
  • Some appliances can let a normal TV show the
    Internet (WebTV)
  • Phone service and Internet service can share the
    same lines, and some computer applications handle
    phone and fax functions over normal phone lines
  • The lines of distinction are blurring

40
Computer Networking
  • Networking allows computers to communicate with
    each other, and share resources (e.g. printers)
  • Networks range in size from global to consumer
  • Networks are much faster than just using telecom
    equipment

41
Types of Networks
  • A single building or group of buildings might use
    a Local Area Network (LAN)
  • Several related sets of facilities might use a
    Metropolitan Area Network (MAN)
  • Global corporations use a Wide Area Network (WAN)
  • Networks can be public or private

42
Switching
  • Networks control the flow of data using switching
  • Two major types of switching
  • Circuit switching changes the circuit to produce
    a physically direct connection is very fast
  • Packet switching sends packets of data which get
    reassembled at the other end to produce the
    message is much cheaper than circuit

43
Protocols
  • Network protocols are the language spoken across
    the network
  • TCP/IP is the language of the Internet
  • NetBEUI is a Windows networking protocol
  • AppleTalk is an Apple networking protocol
  • IPX is a Novell protocol

44
Network Layers
  • Networks function by taking data and adding
    various pieces of information to it in order to
    help it get to its destination
  • The layers of the network describe what that
    information is and how it is used
  • The OSI reference model is the most common system
    for networking

45
Network Hardware
  • Networks rely on each computer having a network
    interface card (NIC) to allow them to be
    connected to the network
  • Like a modem allows connection to the Internet
  • Most NICs are for Ethernet networks
  • Ethernet speeds include 10, 100, and 1000 Mbps
    (the last one is Gigabit Ethernet)

46
Network Hardware
  • Most networks still use cables
  • Thick, thin, or 10base-T Ethernet cables
  • Token Ring cables
  • Coaxial cable
  • Fiber-optic cable
  • Infrared and radio signals are used for wireless
    networks

47
Network Hardware
  • Other network hardware might include
  • Switches, to control where data may go
  • Router, to convert one language into another
  • Hubs, to connect computers which speak the same
    language (protocol)
  • Bridges, to connect major parts of the network
    together

48
Network Terminology
  • Every device on a network (computer, printer,
    etc.) is a node
  • Peer to peer networks work well for small offices
    and home allow sharing of files, printers, and
    Internet connection
  • Client/server networks use servers to manage the
    network, and control access to different nodes

49
Network Operating System
  • Normal operating systems routinely include
    software to allow peer to peer networking
  • Client/Server networks require a networking
    operating system (NOS)
  • Windows Servers (NT, 2000, etc.)
  • Novell NetWare
  • Unix

50
Network Topology
  • Network topology is the layout of a network, like
    a street map to show where roads go
  • The bus topology connects everything along a
    line (like a bus route) good for peer to peer
    networks

51
Network Topology
  • A star topology puts a hub in the middle, and
    everything connects to it
  • A ring topology passes information in a circle,
    and every computer either passes it along or uses
    it (e.g. IBMs Token Ring)
  • More complex topologies are variants on these
    basic structures

52
WAN Structure
  • WANs are essentially a group of networks which
    are connected by a backbone (generally a very
    fast dedicated connection)
  • Most use circuit switching, not packet
  • Each local network connects to the WAN via a POP
    (point of presence), similar to how you connect
    to the Internet

53
WAN Protocols
  • Special protocols are used for WANs
  • X.25 is for phone line connections, goes up to 64
    kbps (like MAC machines)
  • ATM (Asynchronous Transfer Mode) goes up to 155
    Mbps

54
Why WAN?
  • Most WANs are used for sharing files and email
    across a large organization
  • Some also handle transactions (e.g. credit card
    authorization)
  • Specific business-to-business transactions can be
    done securely using Electronic Data Interchange
    (EDI) standards
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