Computer Graphics Metafile (CGM) is a
free and
open international standard
An international standard is a technical standard developed by one or more international standards organizations. International standards are available for consideration and use worldwide. The most prominent such organization is the International O ...
file format for 2D
vector graphics
Vector graphics are a form of computer graphics in which visual images are created directly from geometric shapes defined on a Cartesian plane, such as points, lines, curves and polygons. The associated mechanisms may include vector displ ...
,
raster graphics
upright=1, The Smiley, smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for ...
, and
text
Text may refer to:
Written word
* Text (literary theory)
In literary theory, a text is any object that can be "read", whether this object is a work of literature, a street sign, an arrangement of buildings on a city block, or styles of clothi ...
, and is defined by
ISO
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
Me ...
/
IEC 8632.
ISO/IEC 8632
/ref>
Overview
All graphical elements can be specified in a textual source file that can be compiled into a binary file
A binary file is a computer file that is not a text file. The term "binary file" is often used as a term meaning "non-text file". Many binary file formats contain parts that can be interpreted as text; for example, some computer document files ...
or one of two text representations. CGM provides a means of graphics data interchange for computer representation of 2D graphical information independent from any particular application, system, platform, or device.
As a metafile, i.e., a file containing information that describes or specifies another file, the CGM format has numerous elements to provide functions and to represent entities, so that a wide range of graphical information and geometric primitives can be accommodated. Rather than establish an explicit graphics file format
An image file format is a file format for a digital image. There are many formats that can be used, such as JPEG, PNG, and GIF. Most formats up until 2022 were for storing 2D images, not 3D ones. The data stored in an image file format may be c ...
, CGM contains the instructions and data for reconstructing graphical components to render an image using an object-oriented approach.
Although CGM is not widely supported for web pages and has been supplanted by other formats in the graphic arts, it is still prevalent in engineering, aviation, and other technical applications.
The initial CGM implementation was effectively a streamed representation of a sequence of Graphical Kernel System (GKS) primitive operations. It has been adopted to some extent in the areas of technical illustration
Technical illustration is illustration meant to visually communicate information of a technical nature. Technical illustrations can be components of technical drawings or diagrams. Technical illustrations in general aim "to generate expressive ...
and professional design
A design is the concept or proposal for an object, process, or system. The word ''design'' refers to something that is or has been intentionally created by a thinking agent, and is sometimes used to refer to the inherent nature of something ...
, but has largely been superseded by formats such as SVG and DXF.
The World Wide Web Consortium
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working together in ...
has developed WebCGM, a profile of CGM intended for the use of CGM on the Web.
History
*1986 – ANSI X3 122-1986 (ANSI
The American National Standards Institute (ANSI ) is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organiz ...
X3 committee)
*1987 – ISO 8632-1987 (ISO
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
Me ...
)
*1991 – ANSI/ISO 8632-1987 (ANSI and ISO)
*1992 – ISO 8632:1992, a.k.a. CGM:1992 (ISO)
*1999 – ISO/IEC 8632:1999, 2nd Edition (ISO/IEC JTC1/SC24)
*December 17, 2001 – WebCGM (W3C
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working together in ...
)
*January 30, 2007 �
WebCGM 2.0
(W3C)
*March 1, 2010 �
WebCGM 2.1
(W3C Recommendation)
Further reading
*Arnold, D.B. and P.R. Bono, ''CGM and CGI: Metafile and Interface Standards for Computer Graphics'', Springer-Verlag, New York, NY, 1988.
*Henderson, L.R., and Gebhardt, ''CGM: SGML for Graphics'', The Gilbane Report, Fall 1994.
*Henderson, L.R., and A.M. Mumford, ''The CGM Handbook'', Academic Press, San Diego, CA, 1993.
*Bono, P.R., J.L. Encarnacao, L.M. Encarnacao, and W.R. Herzner, ''PC Graphics With GKS'', Prentice-Hall, Englewood Cliffs, NJ, 1990.
*Vaughan Tay (2001) ''Making It Work'', 5th ed
See also
* Comparison of graphics file formats
References
External links
General
Overview of CGM Standards
Standards
WebCGM 1.0
W3C Recommendation, 17 December 2001
WebCGM 2.0
W3C Recommendation, 30 January 2007
WebCGM 2.1
W3C Recommendation, 1 March 2010
ISO/IEC 8632-1:1999
Part 1: Functional specification
ISO/IEC 8632-1:1999
Part 1: Technical Corrigendum 1
ISO/IEC 8632-1:1999
Part 1: Technical Corrigendum 2
ISO/IEC 8632-3:1999
Part 3: Binary encoding
ISO/IEC 8632-4:1999
Part 4: Clear text encoding
Other
{{Graphics file formats
Graphics file formats
Vector graphics markup languages
Open formats
Graphics standards
American National Standards Institute standards
World Wide Web Consortium standards
ISO standards
IEC standards