Online Computer Terms Dictionary - G

Graphic ALGOL

Generation of shaded perspective picures in real time.

["An Extended ALGOL 60 for Shaded Computer Graphics", B. Jones, Proc ACM Symp on Graphic Languages, Apr 1976].

Graphical Kernel System

<graphics, standard> (GKS) The widely recognised standard ANSI X3.124 for graphical input/output. GKS is worked on by the ISO/IEC group JTC1/SC24. It provides applications programmers with standard methods of creating, manipulating, and displaying or printing computer graphics on different types of computer graphics output devices. It provides an abstraction to save programmers from dealing with the detailed capabilities and interfaces of specific hardware.

GKS defines a basic two-dimensional graphics system with: uniform input and output primitives; a uniform interface to and from a GKS metafile for storing and transferring graphics information. It supports a wide range of graphics output devices including such as printers, plotters, vector graphics devices, storage tubes, refresh displays, raster displays, and microfilm recorders.

(1999-04-01)

Graphical User Interface

<operating system> (GUI) The use of pictures rather than just words to represent the input and output of a program. A program with a GUI runs under some windowing system (e.g. The X Window System, MacOS, Microsoft Windows, Acorn RISC OS, NEXTSTEP). The program displays certain icons, buttons, dialogue boxes, etc. in its windows on the screen and the user controls it mainly by moving a pointer on the screen (typically controlled by a mouse) and selecting certain objects by pressing buttons on the mouse while the pointer is pointing at them. This contrasts with a command line interface where communication is by exchange of strings of text.

Windowing systems started with the first real-time graphic display systems for computers, namely the SAGE Project [Dates?] and Ivan Sutherland's Sketchpad (1963). Douglas Engelbart's Augmentation of Human Intellect project at SRI in the 1960s developed the On-Line System, which incorporated a mouse-driven cursor and multiple windows. Several people from Engelbart's project went to Xerox PARC in the early 1970s, most importantly his senior engineer, Bill English. The Xerox PARC team established the WIMP concept, which appeared commercially in the Xerox 8010 (Star) system in 1981.

Beginning in 1980(?), led by Jef Raskin, the Macintosh team at Apple Computer (which included former members of the Xerox PARC group) continued to develop such ideas in the first commercially successful product to use a GUI, the Apple Macintosh, released in January 1984. In 2001 Apple introduced Mac OS X.

Microsoft modeled the first version of Windows, released in 1985, on Mac OS. Windows was a GUI for MS-DOS that had been shipped with IBM PC and compatible computers since 1981. Apple sued Microsoft over infringement of the look-and-feel of the MacOS. The court case ran for many years.

[Wikipedia].

(2002-03-25)

Graphic Display Interface

<hardware> (GDI) graphics adaptor.

(1995-03-16)

Graphic Language

For specifying graphic operations.

["A Problem Oriented Graphic Language", P.J. Schwinn, proc ACM 22nd Natl Conf, 1967].

[Sammet 1969, p. 677].

graphics accelerator

<graphics, hardware> Hardware (often an extra circuit board) to perform tasks such as plotting lines and surfaces in two or three dimensions, filling, shading and hidden line removal.

(1997-07-14)

graphics adapter

graphics adaptor

graphics adaptor

<hardware, graphics> (Or "graphics adapter", "graphics card", "video adaptor", etc.) A circuit board fitted to a computer, especially an IBM PC, containing the necessary video memory and other electronics to provide a bitmap display.

Adaptors vary in the resolution (number of pixels) and number of colours they can display, and in the refresh rate they support. These parameters are also limited by the monitor to which the adaptor is connected. A number of such display standards, e.g. SVGA, have become common and different software requires or supports different sets.

(1996-09-16)

graphics card

graphics adaptor

Graphics Interchange Format

<graphics, file format> /gif/, occasionally /jif/ (GIF, GIF 89A) A standard for digitised images compressed with the LZW algorithm, defined in 1987 by CompuServe (CIS).

Graphics Interchange Format and GIF are service marks of CompuServe Incorporated. This only affects use of GIF within Compuserve, and pass-through licensing for software to access them, it doesn't affect anyone else's use of GIF. It followed from a 1994 legal action by Unisys against CIS for violating Unisys's LZW software patent. The CompuServe Vice President has stated that "CompuServe is committed to keeping the GIF 89A specification as an open, fully-supported, non-proprietary specification for the entire on-line community including the World-Wide Web".

Filename extension: .gif.

File format.

GIF89a specification.

See also progressive coding, animated GIF.

(2000-09-12)

Graphics Interface Format

<spelling> You mean "Graphics Interchange Format".

(1999-10-11)

Graphics Language Object System

<graphics, language> (GLOS) A language with statements for describing graphics objects (line, circle, polygon, etc.), written by Michael J McLean and Brian Hicks at the University of Queensland, St. Lucia in 1978. New objects are defined using procedures. 2-D transformations are context dependent and may be nested.

[M.J. McLean, "The Semantics of Computer Drafting Languages", PhD thesis, University of Queensland, 1978].

[Hicks, B.W., and McLean, M.J. "A Graphic Language for Describing Line Objects", Proceedings of the DECUS-Australia August 1973 Symposium, Melbourne, 1973].

(2002-06-01)

graphic workstation

<graphics, computer> A workstation specifically configured for graphics works such as image manipulation, bitmap graphics ("paint"), and vector graphics ("draw") type applications. Such work requires a powerful CPU and a high resolution display.

A graphic workstation is very similar to a CAD workstation and, given the typical specifications of personal computers currently available in 1999, the distinctions are very blurred and are more likely to depend on availability of specific software than any detailed hardware requirements.

(1999-05-04)