Topic 2 : Multimedia

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Topic 10 Multimedia

• Define the term multimedia and its elements.
• Understand bitmap and vector images and their
  characteristics.
• Identify audio and video formats and their
  characteristics.
• Understand the areas of multimedia applications.

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Multimedia

• A combination of various types of multimedia
  elements , including sound, animation, video
  ,text and graphics.

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Interactive Multimedia

• Multimedia application that accepts input from
  the users (mouse/keyboard) and performs some
  action in response
• Allows you to choose the material you want to
  view, define the order in which it is presented,
  and obtain feedback on your actions

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Multimedia Elements Text
San-serif Text
Serif Text

• Text with flags (decorations)
• Example Times New Roman, Monotype Corsiva ,
  Courier New

• Text without flags (decorations)
• Example Arial, Helvetica, and Impact

Without flag
flags
Text characters that used to create words,
sentences and paragraphs
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Multimedia Elements Graphics

• Digital presentation of non-text information such
  as drawing, chart or photograph that contains no
  movement or animation.
• 2 types of graphics

Bitmap
Vector
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Bitmap Images

• Bitmap is a collection of pixels that describes
  an image
• The image consists of a matrix of individual dots
  (or pixels) that all have their own color.

• Disadvantages
• When enlarged the picture appears blocky / blur
• File size is quite big

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Bitmap Images
Only smooth at the original size
When enlarge the picture, the software has to
guess where to put the new pixels.
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Bitmap Images
This is a section of the same image when it is
increased to 4x its original size.
In this illustration the original image is
enlarged 6x. The pixels are now clearly visible.
This is the original image.
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Bitmap Images

• Popular bitmap editing programs
• Microsoft Paint
• Adobe Photoshop
• Corel Paint Shop Pro
• Corel Photo Paint
• Ulead PhotoImpact

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• Bitmap graphic formats store the images in
  compressed format
• PCX - the first standard for bitmapped
• GIF ( Graphic Interchange Format)
• JPEG (Joint Photographic Experts Group)
• PNG (Portable Network Graphics)
• TIFF ( Tagged Image File Format) provides the
  highest quality but large file sizes
• BMP uncompressed format

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Vector Graphics

• A graphic image drawn in shapes and lines, called
  paths
• Edit by moving the key points / paths
• The graphical elements of a vector graphics file
  are called objects
• Each object forms one independent unit that is
  characterized by e.g. color and shape

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Advantages vector

• Small file size store instruction for drawing
  an image only
• Reusability easily resized, recolor and
  reshaped
• Not restricted to a rectangular shape can be
  placed over other object

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• Vector are used in
• Macromedia Freehand, Adobe Illustrator, 3D
  application, True Type fonts, charts and graphs
  in spreadsheet programs

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Bitmap vs. Vector

• Small file size
• Maintain quality as the size of the graphics is
  increased
• Easy to edit the drawings as each object is
  independent of the other.
• Created by Adobe Illustrator, Macromedia
  Freehand
• Example of file format ai,wmf.

• Large file size
• Graphics become "blocky" when the size is
  increased
• Not easy to make modification to drawings
• Created by Adobe Photoshop, Paint Shop Pro and
  Paint program
• Example of file format jpeg, gif, bmp, png.

Vector graphic
Bitmap images
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Multimedia Elements Color

• Bit Color and Image Quality
• Each pixel will have a specific number of bits
  assigned to it depending on the monitor and
  computer system
• Each pixel of a digital image can be one and only
  one color.
• Color depth ? the number of colors displayed to
  the monitor
• If n is the number of bits, then the number of
  colors per pixel is 2n

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Color depth
2
16
256
16.7 million
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800
600

• A black and white monitor has one bit per pixel.
• The bit has two possible states on and off
• When it is on, the pixel looks white.
• When it is off, the pixel looks black

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Example of Monochrome display
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Lossy Compression (JPG)
Lossless Compression (GIF PNG)

• Remove small image details that are too small
  for human eye to notice.
• Eliminate redundant orunnecessary information
• Suitable for photograph with smooth continuous
  tones
• JPEG used this technique

• Reduce the image file size without losing any
  image data
• Gifs read horizontally, left to right , row by
  row.
• GIF has just compressed the first row of data
  from 16 to 3 items.

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1
2
3
4
7
8
5
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Before Compression Blue, Blue, White, Blue,
White, Blue, Blue, Blue
After Compression 2 Blue, 1 White,1 Blue, 1
White, 3 Blue
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Anti-aliased

• Anti-aliased
• Technique for smoothing jagged edges in graphic
  by fooling your eyes
• Anti-aliasing increase the file size of GIFs
• Aliased
• Image has jagged or staircase effect

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Anti-aliased OR Aliased ?
Image 1
Image 2
Image 1 The jaggy - aliased scene.
Image 2 The smooth anti-aliased scene.
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Octopus A
Teapot A
Teapot b
Octopus B
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Multimedia Elements Animation

• Animation is a simulation of movement created by
  displaying a series of images (illustration) in
  form of frames.

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Example Animation
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Example of images in series of frames
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Multimedia Elements Audio

• Individual sound files that you download to your
  computer
• Audio sampling ? It is the process of recording
  /digitizing sounds to pc

Step 1 Dictate
Step 2 Convert analog to digital
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Bitrate

• Measurement of the quality of sound
• Describes the amount of digital information being
  stored per second of audio
• Higher the bitrate, the better sound quality but
  the larger file size

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Streaming

• You can play the file as it is downloaded
• Streaming audio format RealAudio, Windows Media
  and Quick Time
• Radio stations use streaming audio to broadcast
  over the Web

Try here ? http//cybermedia.mmu.edu.my/cyb/mmuliv
e.asx
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Audio

• Nonstreaming
• Cannot playback the audio until the entire file
  is completely download
• Nonstreaming audio format WAV, AIFF,AU, midi,
  mp3
• WAV (Win), AIFF (Macs) and AU (UNIX)
• very similar because they were created for use on
  different OS
• Capture the whole sound wave, with very little /
  no compression, so the file sizes can be very
  large

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Audio MIDI

• Allows electronic instruments and computers to
  communicate with each other.
• It's like sheet music for computers, telling
  which instrument (or computerized imitation of an
  instrument) to play which notes when. (doesn't
  contain digitized versions of the sound waves)
• Much smaller than digital audio files.

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Multimedia Elements Video

• Comprises of photographic images that display at
  speeds of 15 to 30 frames per second
• Video files are so large need to be compressed
  to reduce the size
• Compression includes
• Avi
• Quiktime
• mpeg

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Multimedia Application

• Edutainment
• Combination of education and entertainment
• Example Sesame Street Mario Teachers Typing

• Jr. Scientist
• ? Let kids experience being a scientist

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Multimedia Application

• Computer-based training
• Also known as computer-aided instruction (CAI)
• Teach specific skills
• Allow flexible, on-the-spot training
• Interactive training s/ware called courseware
  can be distributed on CD-ROM or shared using
  network

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Example CBT
Kawasakis Computer Based Robot Training solves
these training problems. With interactive
CD-ROMs, students can receive training on their
own PCs, at any time, and at their own pace.
CD-ROM programs also increase information
retention by directly involving employees in the
learning process. They can see, hear, and touch
the training material.
courseware
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Advantages of CBT over traditional training..

• Reduced training time
• One-to-one interaction
• Reduced training costs
• Unique instructional experience
• Makes learning process more interesting
• Allows flexible
• On-the-spot-training

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Multimedia Application

• Web-based Training
• Education / training delivered over the Internet
  using the web browser
• Frequently includes interactive methods, such as
  bulletin boards, chat rooms, instant messaging,
  video conferencing, and discussion threads
• Self-directed, self-paced instruction
• Up-to-date content

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Multimedia Application

• Distance learning/education
• Delivery of education at one location while the
  learning takes place at other location

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Multimedia application

• Virtual Reality
• Computer creates an artificial environment
• Interactively exploring and manipulating the
  environment.
• Used in simulations, which are the computer-based
  models of real-life situations

Sometimes requires you to wear specialized
headgear, body suits and gloves
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Immersive VR
Non -Immersive VR

• The user becomes fully immersed in an
  artificial, 3D world.
• The virtual world is presented in full scale and
  relates properly to the human size
• User feels as if they are a part of the system.
• Requires you to wear specialized gadget
  (headgear, body suits and gloves)

• User is not fully immersed with the system
• The virtual world is not presented in full scale
  and not relates properly to the human size.
• User feels as if they are not part of the
  system.
• Don't require special gadget

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Multimedia Equipment

• Sound card
• CD-ROM and DVD-Drive
• Speaker
• Video display
• Video capture card
• Digital cameras

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Developing Multimedia Applications

• Analysis
• - determine obj. requirements for the
  application
• Design
• - flowchart / map
• Production
• - actual process
• Multimedia Authoring Software
• -allows user to combine all multimedia elements