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Glossary of Multimedia Terms |
- A B C D E F G H I J K L M N O P Q R S T U V W X Y Z -
- A -
Analog - waveforms, with valleys and ridges, referring to the natural form of sound/audio. To store/playback on a computer, analog data is converted to digital data.
- Anti-aliasing - Process used to remove jagged edges in computerized graphics.
- .AVI (Audio Video Interleaved) - Windows format for saving video with sound.
- B -
Bandwidth - the width of the band over which frequencies are transmitted. A band is a portion of the electromagnetic spectrum, defined by the lowest and highest frequencies in it. The bandwidth is the difference between the highest and lowest frequencies. The greater the bandwidth, the greater the carrying capacity. The Federal Communications Commission allocates portions of the band. For example, the band for VHF television broadcast is defined from 54 to 88 million cycles per second. And, of course, the band contains many "channels".
.BMP- bitmap file; the official file format for Microsoft Windows images. BMP is an RGB-only format; it supports Indexed 256 colors, Grayscale and 24-bit RGB documents; does not support CMYK documents.
- C -
.CDR - a vector graphics file format from an illustration package CorelDraw. Generally, graphics created in the .CDR format needs to be exported as a .TIF or .JPEG file in order to be used in any authoring software.
CODEC - program/device that COmpresses/DECompresses digital video.
Compression - Process that reduces the number of bytes required to store/transmit digital video. Typical schemes involve comparing frames and coding-out, or eliminating, inter-frame and intra-frame redundancies. The compression may be done by software, hardware or a combination of the two. On playback, the data is decompressed. (see also: CODEC).
Why compress video data? To reduce storage space and to playback faster. A full-screen (640 x 480 pixels) image with 16.4 million colors takes up 1 Mb of memory. For full-motion, the computer needs to display 30 pictures/frames per second, thus requiring it to "shuffle" 30 Mb of data every second. Storing 10 seconds of video would require 300 Mb.
Compression, Lossless - digitized video containing ALL the original video information.
Compression, Lossy - digitized video which, to save space, does NOT contain all the original video information.
Cross-platform - Files usable/executable with different operating systems. For example, Virtus WalkThrough, a 3-D animator program, can produce "cross-compatible" animation files for Macintosh and DOS/Windows machines. "Power" Mac's let you change to the PC work-mode; "power" PC's can handle Macintosh software/files.
- Sources -
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This page last updated: 22 March 2000
