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

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 Computer Concepts – Illustrated 8th Edition 2

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 Computer Concepts – Illustrated 8th Edition 3

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 Computer Concepts – Illustrated 8th Edition 30