WebCGM Profile

What is it

CGM (Computer Graphics Metafile) has been an ISO standard for vector and composite vector/raster picture definition since 1987. CGM has a significant following in technical illustration, interactive electronic documentation, geophysical data visualization, amongst other application areas and is widely used in the fields of automotive engineering, aeronatics, and the defence industry.

WebCGM is a profile for the effective application of CGM in Web electronic documents. WebCGM has been a joint effort of the CGM Open Consortium, in collaboration with W3C staff and supported by the European Commission Esprit project. It represents an important interoperability agreement amongst major users and implementors of CGM, and thereby unifies current diverse approaches to CGM utilization in Web document applications. WebCGM's clear and unambiguous conformance requirements will enhance interoperability of implementations, and it should be possible to leverage existing CGM validation tools, test suites, and the product certification testing services for application to WebCGM.

While WebCGM is a binary file format and is not "stylable", nevertheless WebCGM follows published W3C requirements for a scalable graphics format where such are applicable. The design criteria for the graphical content of WebCGM aimed at a balance between graphical expressive power on the one hand, and simplicity and implementability on the other. A small but powerful set of metadata elements is standardized in WebCGM, to support the functionalities of: hyperlinking and document navigation; picture structuring and layering; and, search and query on WebCGM picture content.

What is New

May 2011: The WebCGM Working Group is now closed.
01 March 2010: Publication of WebCGM 2.1 (Recommendation)
14 January 2010: Publication of WebCGM 2.1 (Proposed Recommendation)
15 Sept 2009: Publication of WebCGM 2.1 Candidate Recommendation.
04 June 2009: Publication of WebCGM 2.1 second Last Call Working Draft.
30 Jan 2009: Publication of WebCGM 2.1 as second public Working Draft.
17 Sept 2008: Publication of WebCGM 2.1 as First public and Last Call Working Draft.
Aug 2008: WebCGM Working Group is renewed to specify a new WebCGM 2.1 specification.
30 Jan 2007: WebCGM 2.0 is now a W3C Recommendation and an OASIS Standard (press release)
17-Oct-2006: WebCGM 2.0 Testsuite and Implementation report are available

Status

The first WebCGM Profile specification was first issued as a W3C Recommendation on 21 January 1999 (press release); a second edition incorporating errata was issued on 17 December 2001.

A second W3C Recommendation was issued on 30 January 2007, WebCGM 2.0 Recommendation and OASIS Standard (press release).

This means it is a mature document that is considered to contribute towards realising the full potential of the Web. Viewers and editors for CGM are available on many platforms and are being adapted to support the WebCGM Profile specification.

In Aug 2008 a Working Group was chartered to develop the new WebCGM 2.1 Specification.

WebCGM 1.0 and 2.0 documents

Latest WebCGM 2.1 drafts and documents are available on the Working Group page. Former WebCGM 1.0 and WebCGM 2.0 documents are also available.

Products supporting WebCGM

With the adoption of WebCGM, following is a non exhaustive list of products that support WebCGM, for information only.

Viewers and Printers
Browser plug-ins and standalone viewers, WebCGM capable printers
Editors
Illustration, Redlining, Presentation Graphics
Toolkits
Generator and interpreter toolkits
Filters and Converters
Data conversion tools
Services and Miscellaneous

Implementation Conformance Statements

For each product, you will find a pro forma page -- the Implementation Conformance Statement (ICS) -- where the vendor describes the product's level of support for WebCGM. This information is expected to be correct and precise, if you find out that this is not the case please let us know.

WebCGM Samples

Typical aviation technical graphics

MIME type

CGM has been a registered MIME type since 1995. The MIME type for CGM is unusual in that it requires two parameters - the CGM version, and the CGM Profile in use. This is because, without Profiles, it is very difficult to achieve interoperability with CGM (which is why W3C issued a WebCGM Profile). It also means that the MIME type does not need to be re-registered whenever there is a new profile.
Thus the correct MIME type for WebCGM is:

image/cgm;Version=4;ProfileId=WebCGM

WebCGM Bibliography

Papers and presentations on the CGM Open Website.
Reference materials (WebCGM 1.0 Test Suite, WebCGM Demo, XML encoding of CGM, Cascading CGM Profiles, etc)
FAQ on WebCGM