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Chapter 4: File Management, Virus Protection, and Backup. Chapter 1: Computer, Internet, Web, and E-Mail Basics. 1. 1. 1. 1. Chapter 7 Preview. After this chapter, you should be able to:
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Chapter 7: Digital Media Chapter 4: File Management, Virus Protection, and Backup Chapter 1: Computer, Internet, Web, and E-Mail Basics 1 1 1 1
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 Chapter 7: Digital Media
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 Chapter 7: Digital Media
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 Chapter 7: Digital Media
Chapter 7 Outline • Section A • Bitmap Graphics • Section B • Vector and 3-D Graphics • Section C • Digital Video • Section D • Digital Sound Chapter 7: Digital Media
Chapter 7Digital Media Section A: Bitmap Graphics Computer Concepts 8th EditionParsons/Oja
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 Page 344 Chapter 7: Digital Media
How do I create bitmap images? • Paint software – graphics software for creating bitmap graphics • Adobe Photoshop • Jasc Paint Shop Pro • Microsoft Paint Page 344 Chapter 7: Digital Media
How do I convert a printed image into a bitmap? Page 345 Chapter 7: Digital Media
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 Page 345 Chapter 7: Digital Media
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 Page 346 Chapter 7: Digital Media
How can I get the images out of the camera? • Media transfer • Direct cable transfer • Infrared port • Card readers • Floppy disk adapters • E-mail Page 346 Chapter 7: Digital Media
Modifying Bitmap Graphics: What characteristics of a bitmap can I modify? • You can use graphics software to modify or edit bitmap graphics by changing individual pixels • Retouch • Repair • Remove red eye or erase “rabbit ears” • Bitmap graphics require large amounts of storage, and take a long time to load Page 347 Chapter 7: Digital Media
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 Page 347 Chapter 7: Digital Media
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) Page 348 Chapter 7: Digital Media
How does a bitmap’s 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 Page 348 Chapter 7: Digital Media
Can I change a graphic’s 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 Page 349 Chapter 7: Digital Media
Can I change a graphic’s file size? Page 349 Chapter 7: Digital Media
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 Page 350 Chapter 7: Digital Media
How does a color palette work? Page 351 Chapter 7: Digital Media
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 Page 352 Chapter 7: Digital Media
What if a palette doesn’t 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 Page 352-353 Chapter 7: Digital Media
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 Page 353 Chapter 7: Digital Media
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 Page 353 Chapter 7: Digital Media
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 Page 354 Chapter 7: Digital Media
Chapter 7Digital Media Section B: Vector and 3-D Graphics Computer Concepts 8th EditionParsons/Oja
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 Page 356 Chapter 7: Digital Media
What is a vector graphic? Page 356 Chapter 7: Digital Media
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 Page 357 Chapter 7: Digital Media
What tools do I need to create vector graphics? • Digitizing tablet – device that provides a flat surface for a paper-based drawing Page 358 Chapter 7: Digital Media
What tools do I need to create vector graphics? Page 359 Chapter 7: Digital Media
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 Page 360 Chapter 7: Digital Media
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 Page 360 Chapter 7: Digital Media
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 Page 361 Chapter 7: Digital Media
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 <EMBED> tag • Flash graphics – can be static or animated and require less space than SVG graphics, but require a browser plug-in to be viewed Page 361 Chapter 7: Digital Media
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 Page 362 Chapter 7: Digital Media
How do vector graphics relate to 3-D graphics? Page 362 Chapter 7: Digital Media
How do vector graphics relate to 3-D graphics? Page 362 Chapter 7: Digital Media
What do I need to create 3-D graphics? Page 363 Chapter 7: Digital Media
Is it possible to animate 3-D graphics? • 3-D graphics can be animated • Pixar Animation Studios • DreamWorks • Special effects can be created and incorporated into final footage • 3-D computer game animation happens in “real-time” Page 363 Chapter 7: Digital Media
Chapter 7Digital Media Section C: Digital Video Computer Concepts 8th EditionParsons/Oja
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 Page 365 Chapter 7: Digital Media
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 Page 365 Chapter 7: Digital Media
Are there different kinds of digital videos? • Desktop video • Web-based video • DVD video • PDA video Page 365 Chapter 7: Digital Media
How do I create digital video? Page 366 Chapter 7: Digital Media
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 Page 366 Chapter 7: Digital Media
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 Page 367 Chapter 7: Digital Media
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 Page 367 Chapter 7: Digital Media
How do I transfer video footage to my computer? Page 367 Chapter 7: Digital Media
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 Page 368 Chapter 7: Digital Media