the transfer of pictorial data into and out of a computer. Using analog-to-digital conversion techniques, a variety of devices—such as curve tracers, digitizers, and light pens—connected to graphic computer terminals, computer-aided design programs, or optical scanners can be used to store pictorial data in a digital computer. By reversing the process through digital-to-analog conversion techniques, the stored data can be displayed in graphical form on a mechanical plotting board, or plotter, or on a televisionlike graphic display terminal. Raster graphics stores and displays images as a bit map, a series of closely spaced dots (or pixels) arranged in rows and columns. Vector, or object-oriented, graphics stores the images as mathematical formulas; images are displayed by calculating the coordinates of the end points and then drawing lines between them. Computer graphics capabilities range from the simple display of digital tabulations as line graphs and pie charts to complex animation and elaborate special effects for television and motion pictures. Computer graphics are used in architecture, art, computer-aided design, electronic games, flight simulators for pilot training, and molecular modeling.

See J. D. Foley, Computer Graphics: Principles and Practices (1990); K. S. Chauveau, J. S. Chin and T. N. Reed, The Computer Graphics Interface (1991); Sun Microsystems, An Introduction to Computer Graphics Concepts: From Pixels to Pictures (1991); R. T. Stevens, Quick Reference to Computer Graphics Terms (1993); I. V. Kerlow and J. Rosebush, Computer Graphics for Designers and Artists (2d ed. 1994); J. Peddie, High-Resolution Graphics Display Systems (1994).

The Columbia Encyclopedia, Sixth Edition Copyright© 2004, Columbia University Press. Licensed from Lernout & Hauspie Speech Products N.V. All rights reserved.

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