1. Computer Concepts – Illustrated 8th edition
Unit H: Digital Media

2. Objectives Introduce digital audio
Explore digital audio and synthesized sound
Introduce bitmap graphics
Modify bitmap graphics
Understand color and compression
Computer Concepts – Illustrated 8th Edition
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3. Objectives (continued)
Introduce vector graphics
Explore 3D graphics
Introduce digital video
Explore digital video equipment and software
Store and edit desktop video
Computer Concepts – Illustrated 8th Edition
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4. Introducing Digital Audio
Sounds represented in binary format
For use in digital devices
Created by sampling the analog sound wave at periodic intervals
Player software needed to play an audio file on a computer or portable player
Digital music is available from a variety of sources
Computer Concepts – Illustrated 8th Edition

5. Figure H-1: Sampling a sound wave
Computer Concepts – Illustrated 8th Edition

6. Exploring Digital Audio and Synthesized Sound
Synthesized sound: artificially created sound
To play digital audio, a computer uses:
Sound card or sound card circuitry
Software
MIDI (Musical Instrument Digital Interface)
Specifies a standard way to store music data for synthesizers, electronic MIDI instruments, and computers
Computer Concepts – Illustrated 8th Edition

7. Exploring Digital Audio and Synthesized Sound (continued)
Speech synthesizer
Used by a computer to output spoken words
Uses speech synthesis
Process computers use to produce sound that resembles spoken words
Strings together phonemes (basic sound units)
Speech recognition (or voice recognition)
Ability of a computer to understand the spoken word
Computer Concepts – Illustrated 8th Edition

8. Introducing Bitmap Graphics
Digital graphics: images that have been created as or converted to a digital format
Bitmap graphic: composed of a grid of dots
Grid divides picture into cells, called pixels
Ways to get a bitmap graphic:
Create a bitmap graphic from scratch
Use a scanner
Use a digital camera
Computer Concepts – Illustrated 8th Edition

9. Figure H-9: A bitmap graphic
Computer Concepts – Illustrated 8th Edition

10. Introducing Bitmap Graphics (continued)
Ways to transfer images from a digital camera to a computer:
Direct cable transfer
Infrared port
Media transfer
Docking station
Card reader
Computer Concepts – Illustrated 8th Edition

11. Modifying Bitmap Graphics
Graphics software can be used to enhance or change bitmap graphics
Resolution: dimensions of the grid that forms a bitmap graphic
A megapixel is one million pixels
Cropping: removing part of an image
Pixel interpolation
Process used by graphics software to increase the resolution of a bitmap graphic
Computer Concepts – Illustrated 8th Edition

12. Figure H-15: Resolution and image size
Computer Concepts – Illustrated 8th Edition

13. Understanding Color and Compression
Color depth: number of colors available for use in an image
Display of colors
Each screen pixel displays a color based on the intensity of red, green, and blue signals
Each red, green, and blue signal is assigned a value ranging from zero to 255
Data compression: recoding data so that it requires fewer bytes of storage space
File compression software allows you to manually compress files
Computer Concepts – Illustrated 8th Edition

14. Understanding Color and Compression (continued)
Color palette
Holds the selection of colors
Allows you to select a group of colors to use for a bitmap graphic
Grayscale palette: displays an image using shades of gray
System palette: selection of colors used by operating system for desktop icons and controls
Web palette: contains a standard set of colors
Computer Concepts – Illustrated 8th Edition

15. Introducing Vector Graphics
A vector graphic consists of a set of instructions for creating an image
Used for line art, logos, simple illustrations, diagrams, etc.
Compared with bitmap graphics:
Usually requires less storage space
Resizes better
Easier to edit an object in a vector graphic
Computer Concepts – Illustrated 8th Edition

16. Figure H-21: Resizing graphic images
Computer Concepts – Illustrated 8th Edition

17. Introducing Vector Graphics (continued)
Drawing software: vector graphics software
Used to create vector graphics from scratch
To apply color to vector graphics:
Simply fill a shape with a solid color
Create a gradient
Rasterization: process used to create a bitmap graphic from a vector graphic
Tracing software: used to convert a bitmap graphic into a vector graphic
Computer Concepts – Illustrated 8th Edition

18. Exploring 3D Graphics
Wireframe: provides a framework for the 3D graphic
Rendering: process of covering a wireframe with surface color and texture
Ray tracing: technique for adding light and shadows to a 3D image
3D graphics can be animated
3D software
Maya, Autodesk 3ds Max, Smith Micro Poser, and DAZ Bryce
Computer Concepts – Illustrated 8th Edition

19. Figure H-24: Creating a 3D graphic
Computer Concepts – Illustrated 8th Edition

20. Introducing Digital Video
Video: a series of frames projected at a rate fast enough to fool the human eye into perceiving continuous motion
Digital video: uses bits to store data for each video frame
Footage for digital video can be supplied by:
Video camera, videotape, television, DVD, or digital video recording (DVR) device
Computer Concepts – Illustrated 8th Edition

21. Introducing Digital Video (continued)
Types of digital videos based on platform:
Desktop video
Web-based video
Streaming video technology
DVD-Video
PDA video
Digital video is stored in a variety of file formats:
Flash video, AVI, QuickTime Movie, MPEG, RealMedia, ASF, VOB, etc.
Computer Concepts – Illustrated 8th Edition

22. Exploring Digital Video Equipment and Software
Option for creating digital video:
Digital video (dv) camera
Generally produces higher quality video than an analog or a videoconferencing camera
Use analog video camera to shoot footage
Later convert footage to a digital video format
Video capture: process of converting analog video signals into digital format
Videoconferencing camera (often called a Web cam or Web camera)
Video editing software
Computer Concepts – Illustrated 8th Edition

23. Storing and Editing Desktop Video
To reduce file size of original video:
Decrease video display size
Reduce the frame rate
Compress data
Codec (compressor/decompressor)
Software that compresses a video stream when a video is stored and decompresses the file when the video is played
Computer Concepts – Illustrated 8th Edition

24. Storing and Editing Desktop Video (continued)
Video editing
Linear editing moves footage from one videotape to another
Nonlinear editing uses a random-access device to hold both the original footage and finished video
Video editing software
Adobe Premiere, Apple Final Cut Pro, Windows Movie Maker, Ulead VideoStudio
DVD authoring software provides tools to package completed video footage into a professional-style DVD
Computer Concepts – Illustrated 8th Edition

25. Figure H-36: Video editing
Computer Concepts – Illustrated 8th Edition

26. Reference Tables for Media Files
Table H-1: Popular file formats for audio
Computer Concepts – Illustrated 8th Edition

27. Reference Tables for Media Files (continued)
Table H-2: Popular file formats for graphics
Computer Concepts – Illustrated 8th Edition

28. Reference Tables for Media Files (continued)
Table H-3: Popular file formats for desktop video
Computer Concepts – Illustrated 8th Edition

29. Talking Points: Who Owns the Rights?
Fair use and digital rights management
Copyright: gives certain exclusive rights to author of a program or owner of copyright
Digital rights management (DRM): techniques used by copyright holders to limit access and use of digital content
Fair use: right to use portions of copyrighted material without the permission of the copyright holder for certain purposes
Time shifting
Place shifting
Format shifting
Computer Concepts – Illustrated 8th Edition

30. Summary This chapter introduced: Digital audio
Speech synthesis and its applications
Bitmap graphics
Vector graphics
3D graphics and 3D animations
Creating and editing video on your desktop
Digital rights management
Place shifting and time shifting technologies
Computer Concepts – Illustrated 8th Edition
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