Computer Graphics Metafile
{{short description|Image file format family}}
{{Infobox file format
| name = Computer Graphics Metafile
| icon =
| logo =
| screenshot =
| caption =
| extension = {{mono|.cgm}}
| mime = {{mono|image/cgm}}[https://www.iana.org/assignments/media-types/image/ IANA Image Media Types]
| type code =
| uniform type =
| magic =
| released = {{Start date and age|1986}}
(ANSI X3 122-1986)
| latest release version =
| latest release date =
| genre = Vector image format
| container for =
| contained by =
| extended from = Graphical Kernel System
| extended to =
| url = {{URL|standards.iso.org/ittf/PubliclyAvailableStandards/index.html|ISO/IEC 8632}}
}}
Computer Graphics Metafile (CGM) is a free and open international standard file format for 2D vector graphics, raster graphics, and text, and is defined by ISO/IEC 8632.[http://standards.iso.org/ittf/PubliclyAvailableStandards/index.html ISO/IEC 8632]
Overview
All graphical elements can be specified in a textual source file that can be compiled into a binary file 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, 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It has been adopted to some extent in the areas of technical illustration and professional design, but has largely been superseded by formats such as SVG and DXF.
The World Wide Web Consortium has developed WebCGM, a profile of CGM intended for the use of CGM on the Web.
History
- 1986 – ANSI X3 122-1986 (ANSI X3 committee)
- 1987 – ISO 8632-1987 (ISO)
- 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)
- January 30, 2007 – [http://www.w3.org/TR/2007/REC-webcgm20-20070130/ WebCGM 2.0] (W3C)
- March 1, 2010 – [http://www.w3.org/TR/2010/REC-webcgm21-20100301/ 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
References
{{reflist|30em}}
External links
=General=
- [http://www.itl.nist.gov/div897/ctg/graphics/cgm_std.htm Overview of CGM Standards]
- [https://www.fileformat.info/format/cgm/egff.htm CGM File Format Summary]
- [http://www.cgmopen.org/webcgm/index.html WebCGM Resource Page]
- [http://xml.coverpages.org/webCGM.html Technology Reports: WebCGM]
- [http://www.w3.org/TR/NOTE-cgm-970618.html Use of CGM as a Scalable Graphics Format]
- [http://www.cgmopen.org/technical/index.html CGM Open - Reference documents & related materials for CGM and WebCGM]
=Standards=
- [http://www.w3.org/TR/REC-WebCGM/ WebCGM 1.0], W3C Recommendation, 17 December 2001
- [http://www.w3.org/TR/webcgm20/ WebCGM 2.0], W3C Recommendation, 30 January 2007
- [http://www.w3.org/TR/webcgm21/ WebCGM 2.1], W3C Recommendation, 1 March 2010
- [http://standards.iso.org/ittf/PubliclyAvailableStandards/c032378_ISO_IEC_8632-1_1999(E).zip ISO/IEC 8632-1:1999] Part 1: Functional specification
- [http://standards.iso.org/ittf/PubliclyAvailableStandards/c044114_ISO_IEC_8632-1_1999_Cor_1_2006(E).zip ISO/IEC 8632-1:1999] Part 1: Technical Corrigendum 1
- [http://standards.iso.org/ittf/PubliclyAvailableStandards/c050315_ISO_IEC_8632-1_1999_Cor_2_2007.zip ISO/IEC 8632-1:1999] Part 1: Technical Corrigendum 2
- [http://standards.iso.org/ittf/PubliclyAvailableStandards/c032380_ISO_IEC_8632-3_1999(E).zip ISO/IEC 8632-3:1999] Part 3: Binary encoding
- [http://standards.iso.org/ittf/PubliclyAvailableStandards/c032381_ISO_IEC_8632-4_1999(E).zip ISO/IEC 8632-4:1999] Part 4: Clear text encoding
= Other =
- [http://www.cgmopen.org/technical/webcgm_svg.htm WebCGM and SVG: A Comparison]
- [http://www.agocg.ac.uk/train/cgm/examples/cgmindex.htm CGM Examples]
{{List of International Electrotechnical Commission standards}}
{{Vector graphics markup languages|state=uncollapsed}}
{{ISO standards}}
{{Graphics file formats}}
Category:Graphics file formats
Category:Vector graphics markup languages
Category:American National Standards Institute standards