CGM is an open standard - no single entity owns the specification. Therefore, no single company can hold your data hostage to their software.

 

CGM is an established standard with a long track record. Most major CAD packages will create a CGM file. Many large companies have decades worth of CGM files.

 

CGM is a scalable vector format, defined from day one as a technical standard. It is a proven standard in several industries.

 

CGM can also contain raster images. This is useful if you seek to get ALL of your data into a single format, thereby eliminating the need for multiple viewers, and dramatically reducing the need for maintenance on multiple formats.

 

CGM is a completely self-contained interchangeable format. No extra source or image files are necessary to transmit an image.

 

With the advent of WebCGM, a new international standard, you can add hyperlinks and make hotspots within the file to link to other CGM files or Internet resources.

 

CGM Standard (ISO 8632-1: 1999) Part 1 Functional Specification

 

CGM Standard (ISO 8632-1: 1999) Part 3 Binary Encoding

 

CGM Standard (ISO 8632-1: 1999) Part 4 Clear Text Encoding

 

The CGM Handbook (Amazon)

 

CGM Open Reading Library

 

Overview Of The CGM Standard by NIST

 

WebCGM Standard V2.0

 

W3C Introduction to WebCGM

 

NIST CGM validation test procedures

 

Registry of CGM Extensions

 

WebCGM Test Suite

CGM FAQ

What is CGM?The Computer Graphics Metafile (CGM) is the international standard for storage and exchange of two-dimensional graphical data. Initially developed as a vector format it has been extended to include raster capabilities and provides a useful format for combined raster and vector images. What does "metafile" mean?A metafile is a list of commands that can be executed to draw geometric components, such as ploylines, polygons or text elements. The metafile may also include commands to control the style of these objects such as line color. The CGM standard specifies which elements are allowed to occur in which positions in a metafile. What is the difference between a Vector and a Raster image?A vector graphic is a graphic drawn using mathematically defined objects such as polygons, lines and text. A Raster graphic is drawn using an array of dots. Is CGM a Raster or a Vector format?CGM is a robust Vector graphics format that can also be used to describe Raster images. A more accurate description would be to say it is a geometric description language. CGM describes pictures and graphical elements in high level geometric terms such as lines, circles, arcs, ellipses, polygons, text strings, and cell arrays. What sort of standard is CGM?CGM provides a file format suitable for the storage and retrieval of image information. The file format consists of an ordered set of elements that may be used to describe images in a neutral way that can be understood by different systems, applications and devices irrespective of architecture. CGM became an international standard in 1987 as ISO/IEC 8632 and was adopted as a national standard in many countries. Following a number of published amendments to give it increased functionality a revised standard was published in 1992 as ISO 8632:1992 and again in 1999 as ISO 8632:1999 Why are there different versions of CGM?Different CGM files can conform to different versions of the Standard as it was being developed. There are three main versions of CGM in common usage.

Version 1 refers to CGM files that conform to the original, 1987, version of the published standard.

Version 3 refers to CGM files that conform to the 1992 version of the standard which includes advanced graphical elements such as splines and polybezier curves. It also enriched the graphical attributes to allow for greater definition of engineering drawings and technical illustrations. Version 3 is mainly used in Technical Illustration systems.

Version 4 refers to CGM files that conform to the 1999 version of the standard that added Application Structuring. This allows the CGM to contain non-graphical information in addition to graphical content. This allows CGM to be used for a wide range of application interactive graphics, hotspots and hyperlinking.
What are CGM Profiles?Profiles are a subset of the standard developed independently by standards groups within specific industries. The purpose of a profile is to improve the interoperability of CGM within a specific technical community. The most popular profiles are those developed by the aerospace, defense, petroleum, automotive, and rail industries. The World Wide Web Consortium (W3C) have also developed a specific profile for the use of CGM on the Web. What is WebCGM?Web CGM is a profile of the CGM standard (ISO 8632:1999) that describes how CGM vector, raster, and hybrid graphics are to be used on the web. It was developed between the W3C and the CGM Open Consortium and represents a consensus of users and vendors of CGM on a way to exchange dynamic hyperlinked CGM files over the Web. WebCGM provides a vendor-neutral standard for 2D graphics that enables creators and consumers to exchange, view, and browse intelligent, vector, raster, or hybrid graphics reliably. Users are able to create graphics in one tool and view / browse them in another without loss or distortion of information. What are the Industry specific CGM Profiles?The main industry defined CGM profiles are as follows:

CALS CGM profile is a Department of Defense standard (MIL_PRF-28003 Rev B) entitled "Digital Representation for Communication of Illustration Data: CGM Application Profile." It is part of the CALS (Continuous Acquisition and Life-Cycle Support) family of standards.

ATA CGM profile is part of the Air Transport Association (ATA) specification 2100 that governs technical documentation for the manufacture and operation of commercial airplanes. The exchange profile GREXCHANGE is based on CGM Version 3 and is suitable for the exchange of technical manuals, publishing applications, and visualization. A second profile IGEXCHANGE provides for the transfer of intelligence associated with graphical data and is based on application structuring as defined in CGM Version 4.

CGM PIP is the Petroleum Industry Profile for CGM. It was developed for graphical interchange between applications in the petroleum exploration and production community. This standard is based on CGM Version 3 and CGM+, a format for graphical representation of geophysical data.

J2008 is the automotive industry standard for the exchange of technical documentation and states that all graphics should be in CGM format. It references the ATA 2100 CGM profiles.

RIF / EPECS is the Electronic Parts Catalog Exchange Standard of the Rail Industry Forum. It also references the ATA 2100 specification for the use of CGM as graphics exchange standard.