Computer Concepts 8

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Chapter 4 File Management, Virus Protection, and
Backup
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Chapter 1 Computer, Internet, Web, and E-Mail
Basics
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Chapter 7 Preview

• After this chapter, you should be able to
• Describe the advantages, disadvantages, and uses
  for digital media, such as bitmap graphics,
  vector graphics, 3-D graphics, 3-D animations,
  desktop video, waveform audio, MIDI music, speech
  synthesis, and speech recognition
• List the equipment and software that can be used
  to work with various types of digital media
• Identify digital media files by their file
  extensions
• Understand the advantages and disadvantages of
  using each type of digital media on the Web

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Chapter 7 Preview

• Explain how resolution, image size, color depth,
  and color palettes can be manipulated to adjust
  the file size of a bitmap graphic
• Describe procedures required to convert bitmap
  graphics into vectors and vector graphics into
  bitmaps
• Explain how wireframes, rendering, and ray
  tracing apply to 3-D graphics
• Define the differences between digital video and
  3-D animation

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Chapter 7 Preview

• Describe how to shoot, capture, edit, and process
  digital video
• Explain how window size, frame rate, and
  compression affect file size for a desktop video
• Describe the formats used for digital music
• Explain how to download music files and transfer
  them to portable audio players

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Chapter 7 Outline

• Section A
• Bitmap Graphics ??
• Section B
• Vector and 3-D Graphics??????
• Section C
• Digital Video ????
• Section D
• Digital Sound ????

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Chapter 7Digital Media????

• Section A Bitmap Graphics
• ??

Computer Concepts 8th Edition
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Bitmap Basics What is a bitmap graphic?

• Bitmap graphic raster graphic, consists of a
  grid of dots
• The color of each dot is stored as a binary
  number
• Example

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How do I create bitmap images?

• Paint software graphics software for creating
  bitmap graphics
• Adobe Photoshop
• Jasc Paint Shop Pro
• Microsoft Paint
• Bit-by-bit editing

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How do I convert a printed image into a bitmap?
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When should I use a digital camera rather than a
scanner?

• Digital camera digitizes real objects
• Takes photo in digital format, which you can then
  transfer directly to your computer

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How does a digital camera store images?

• Some digital cameras store images on floppy
  disks, CDs, mini-CDs, or miniature hard disk
  drives
• Solid state storage popular technology for
  digital camera memory modules
• Holds data without consuming power
• Memory card

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How can I get the images out of the camera?

• Media transfer, e.g disk
• Direct cable transfer
• Infrared port
• Card readers
• Floppy disk adapters
• E-mail

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Modifying Bitmap Graphics What characteristics
of a bitmap can I modify?

• You can use graphics software to modify or edit
  bitmap graphics by changing any individual pixels
• Retouch
• Repair
• Remove red eye or erase rabbit ears
• Bitmap graphics can require large amounts of
  storage, and take a long time to load

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Image Resolution How does resolution pertain to
bitmap graphics?

• Resolution dimensions of the grid that forms a
  bitmap graphic
• Number of horizontal and vertical pixels that it
  contains
• 150 x 100 150 pixels across and 100 pixels
  high, 1600 x 1200
• 1.9 Megapixels (1600x1200)
• 3.5 Megapixels (2160x1440)

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Size of Graphics Image

• Each pixel is 1 or more bits
• Enlarging an image pixelates it

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How do I specify the size of a printed image?

• Most graphics software lets you specify the size
  at which an image is printed without changing the
  resolution of the bitmap graphic
• Get better printout if an image meets or exceeds
  the printers dpi (dots per inch)

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How does a bitmaps resolution relate to what I
see on the screen?

• Typically, one pixel on the graphic corresponds
  to one pixel on the screen
• If image is larger than screen, you will have to
  scroll

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Can I change a graphics file size?

• Cropping process of selecting part of an image
• Resolution dependent quality of the image
  depends on its resolution
• Can reduce image quality
• Pixel interpolation creates new pixels by
  averaging the colors of nearby pixels
• Pixelated undesirable jagged appearance

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Can I change a graphics file size?
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Color Depth and Palettes What is color depth?

• The number of colors that are available for use
  in an image
• Larger number, better quality and larger file
  size. Why?
• 8-bit
• 24-bit or True Color

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How does a color palette work?
8-bits each
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How do I select a color palette?

• Use color palette or color picker tool
• Grayscale palette displays an image using
  shades of gray (usually 256 shades of gray)
• System palette selection of colors used by the
  operating system
• Windows has 20 permanent colors and 236 that can
  be changed
• Web palette standard set of colors used by the
  Internet Web browsers

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What if a palette doesnt contain the colors
needed for an image?

• Dithering uses patterns composed of two or more
  colors to produce the illusion of additional
  colors and shading, relying on the human eye to
  blend colors and shapes

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Bitmap Graphics Formats Are there different
kinds of bitmap graphics?

• BMP native bitmap graphic file format of
  Microsoft Windows OS
• PCX one of original personal computer bitmap
  graphics file formats (8-bit 256 color)
• TIFF (Tag Image File Format) highly flexible
  and platform-independent graphics file format
• Supports True Color
• Used by scanners and digital cameras

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Are there different kinds of bitmap graphics?

• JPEG graphics format with built-in compression
• You control level of compression
• Uses True Color
• GIF limited to 256 colors
• PNG 48-bit True Color, compresses without
  losing data
• Public domain format

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How do I know which graphics format to use?

• BMP Buttons and other controls
• PCX Not used with much frequency
• TIFF High-resolution images and photos
• JPEG Photographic or scanned images
• GIF Popular for Web graphics
• PNG Alternative to GIF

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Chapter 7Digital Media

• Section B Vector and 3-D Graphics
• ??????

Computer Concepts 8th Edition
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Vector Graphics Basics What is a vector graphic?

• Consists of set of instructions for re-creating a
  picture
• Contains the instructions that the computer needs
  to create the shape, size, position, and color
  for each object in an image

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What is a vector graphic?
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How do vector graphics compare with bitmap
graphics?

• Vectors resize better than bitmaps
• Vector images usually require less storage space
  than bitmaps
• It is easier to edit an object in a vector
  graphic than an object in bitmap graphic
• Vector graphics are not usually as realistic as
  bitmap images, simpler and more like a cartoon or
  linedrawing

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What tools do I need to create vector graphics?

• Digitizing tablet device that provides a flat
  surface for a paper-based drawing
• AutoCAD for architects

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What tools do I need to create vector graphics?
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Vector-to-Bitmap Conversion Is it possible to
convert a vector graphic into a bitmap?

• Rasterization works by superimposing a grid over
  a vector image, and determining the color for
  each pixel
• Once converted, the resulting graphic no longer
  has the qualities of a vector graphic
• Metafiles - bitmaps vectors

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How about converting a bitmap graphic into a
vector graphic?

• This process is more difficult
• Tracing software locates the edges of objects in
  a bitmap image and converts the resulting shapes
  into vector graphics objects

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Vector Graphics on the Web Do vector graphics
work on the Web?

• Browsers support a limited number of graphics
  formats GIF and JPEG
• Support for vector graphics has been slow, but
  plug-ins and players are currently available

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Which vector graphics formats can be used on the
Web?

• SVG (Scalable Vector Graphics) designed for the
  Web
• Automatically resized when displayed on different
  screens
• Uses ltEMBEDgt tag
• Flash graphics can be static or animated and
  require less space than SVG graphics, but require
  a browser plug-in to be viewed
• Animated GIFs much larger

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Advantages of Using Vector Graphics on the Web

• Consistent Quality
• Looks the same on all screens
• Resizes
• Searchable
• Text in vector, e.g. labels
• Smaller than bitmaps

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3-D Graphics How do vector graphics relate to
3-D graphics?

• 3-D graphics stored as a set of instructions
• Wireframe framework for a 3-D graphic
• Rendering process of covering a wireframe with
  surface color and texture
• Ray tracing technique for adding light and
  shadows to a 3-D image

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How do vector graphics relate to 3-D graphics?
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How do vector graphics relate to 3-D graphics?

• Rotating the graphic

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What do I need to create 3-D graphics?
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Is it possible to animate 3-D graphics?

• 3-D graphics can be animated
• Pixar Animation Studios
• DreamWorks
• Toy Story, LOR, etc.
• Special effects can be created and incorporated
  into final footage
• 3-D computer game animation happens in
  real-time, rendered as you play
• Graphics cards

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VRML

• Virtual Reality Markup Language
• Similar to vector graphics
• Interpreted by plug-ins
• Allows you to move thru graphics
• http//prt.fernuni-hagen.de/lehre/KURSE/PRT001/cou
  rse_main/node19.html

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Chapter 7Digital Media

• Section C Digital Video
• ????

Computer Concepts 8th Edition
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Desktop Video Basics What is digital video?

• Uses bits to store color and brightness data for
  each video frame
• Stored on hard disks, CDs, DVDs, videotapes,
  memory cards, or the Web
• Footage can be supplied by
• Video camera
• Videotape
• Television
• DVD
• Digital recording device

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What is digital video?

• Video is composed of a series of frames
• Each frame is essentially a still picture (can be
  stored as bitmap graphic)
• Frame rate number of frames per second

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Are there different kinds of digital videos?

• Desktop video
• Web-based video
• DVD video
• PDA video

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How do I create digital video?
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Is it necessary to use a digital video camera for
filming digital video?

• You can use analog or digital video camera to
  shoot footage
• Digital video camera stores footage as a series
  of bits
• Analog video camera stores as continuous track
  of magnetic patterns
• Must be digitized
• Videoconferencing cameras attach directly to a
  computer

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What are the advantages of a digital video camera?

• Captures video data in digital format which can
  then be directly transferred to a computer for
  editing
• Produce higher quality video than analog or
  videoconferencing cameras
• Images tend to be sharper and more colorful
• Higher quality of original video, the better the
  final video will look

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How do I transfer video footage to my computer?

• Send the data over a cable that connects your
  camera to your computer
• Video capture device converts analog camera
  signal into digital data

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How do I transfer video footage to my computer?
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How do I control the transfer process?

• Video capture software allows you to start and
  stop the transfer, and select the display size,
  frame rate, filename, and file format for your
  video footage

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Video Editing Do I need special equipment for
video editing?

• Linear editing recording segments from one
  videotape onto another tape
• Non-linear editing requires a computer hard
  disk and video editing software
• Can use random access devices to easily edit and
  arrange footage

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How do I edit a video?
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How does video footage become a digital video?

• You can save your digital video in a variety of
  formats
• AVI
• QuickTime Movie
• MPEG
• RealMedia
• WMV
• VOB

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Which compression techniques should I use?
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How do Web-based videos work?

• Streaming video sends small segment of the
  video to your computer and begins to play it
• Web server sends next part of the file to your
  computer, and so on, until the video ends

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How do I add a video to a Web page?

• 2 styles
• External video displays a link to a video file
• ltA HREF ducks.avigt 1.5 MB AVI Video lt/Agt
• Internal video (inline video) uses EMBED tag,
  in-place video
• ltEMBED SRCducks.avi width145 height60gt

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How does Internet connection speed affect Web
videos?

• Dial-up connections are slow
• High-speed Internet connections provide much more
  bandwidth for streaming video
• Most Web sites provide one video file thats
  optimized for dial-up and one optimized for
  high-speed (DSL, cable, and ISDN connections)

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Can standalone DVD players work with desktop and
Web video formats?

• Many DVD players are not able to read desktop
  video or Web file formats
• Cannot read DVDs formatted for computer data
  storage
• Commercial DVD movies are stored using the
  industry-standard DVD-video disk format

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Chapter 7Digital Media

• Section D Digital Sound
• ????

Computer Concepts 8th Edition
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Waveform Audio What is waveform audio?

• Waveform audio is a digital representation of
  sound.
• Music, voice, and sound effects can all be
  recorded as waveforms

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Does sampling rate affect sound quality?
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How does a computer produce waveform audio?

• Sound card contains a variety of input and
  output jacks, plus audio-processing circuitry
• Plugs into a PCI expansion slot inside the system
  unit

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How does a computer produce waveform audio?

• Digital signal processor performs three
  important tasks
• Transforms digital bits into analog waves
• Transforms analog waves into digital bits
• Handles compression and decompression, if
  necessary

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What type of software is required to record and
play waveform audio files?

• To play, you must use an audio player
• Microsoft Media Player
• To record, you may need another software
  component
• Microsoft Sound Recorder
• Software may be part of your operating system or
  purchased separately

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Can I add waveform audio files to my Web pages?

• Yes, files can be embedded using HTML
• ltEMBED SRC daisy.wavgt or ltBGSOUND
  imagine.wavgt
• Use a streaming format to avoid lengthy delays

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How can I listen to my digital music collection
when Im away from my computer?

• A portable audio player stores digital music
• You can transfer digital music from your computer
  to your portable audio player
• MP3 is the most popular audio format for digital
  audio

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MIDI Music What is MIDI music?

• Synthesized sound artificially created sound
• MIDI (Musical Instrument Digital Interface)
  specifies standard way to store music data
• MIDI sequence encoded music stored as .mid,
  .cmf, or .rol
• Most sound cards are equipped to capture data
  from a MIDI instrument
• Wavetable set of pre-recorded musical
  instrument sounds

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When would I use MIDI music?
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Speech Recognition and Synthesis Whats the
difference between speech synthesis and speech
recognition?

• Speech synthesis process by which machines
  produce sound that resembles spoken words
• Speech recognition (or voice recognition)
  ability of machine to understand spoken words

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How does speech synthesis work?

• Phonemes basic sound units strung together by
  speech synthesizers
• Text-to-speech software generates sounds that
  are played through your computers standard sound
  card
• Speech synthesis is a key technology in wireless
  communication

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How does speech recognition work?

• Speech recognition software analyzes the sounds
  of your voice and converts them to phonemes
• Next, the software analyzes the content of your
  speech it compares the phonemes to the words in
  a digital dictionary
• Can be integrated with word processing software
• Windows XP includes speech recognition software

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Conclusion

• You should now be able to
• Describe the advantages, disadvantages, and uses
  for digital media, such as bitmap graphics,
  vector graphics, 3-D graphics, 3-D animations,
  desktop video, waveform audio, MIDI music, speech
  synthesis, and speech recognition
• List the equipment and software that can be used
  to work with various types of digital media
• Identify digital media files by their file
  extensions
• Understand the advantages and disadvantages of
  using each type of digital media on the Web

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Conclusion

• Explain how resolution, image size, color depth,
  and color palettes can be manipulated to adjust
  the file size of a bitmap graphic
• Describe procedures required to convert bitmap
  graphics into vectors and vector graphics into
  bitmaps
• Explain how wireframes, rendering, and ray
  tracing apply to 3-D graphics
• Define the differences between digital video and
  3-D animation

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Conclusion

• Describe how to shoot, capture, edit, and process
  digital video
• Explain how window size, frame rate, and
  compression affect file size for a desktop video
• Describe the formats used for digital music
• Explain how to download music files and transfer
  them to portable audio players