There has been a long-term requirement in the World Wide Web for an additional type of graphics object to display scalable or vector graphics. These are particularly useful for showing technical drawings and maps, where much detail can be lost in a raster image and it is useful to zoom in on details, but can also be useful for the display of other schematic data (ie histograms).
A detailed comparison of CGM against the Scalable Graphics Requirement is given in the next section. The authors believe that CGM fulfills most of the requirements in [4], but there is a danger that unconstrained use of CGM would cause problems with portability and interoperability. This paper is an attempt to address some of the portability issues and to recommend how to use CGM on the World Wide Web. This will include the use of parameters to the OBJECT tag, how add links to CGM and the possible definition of a Web profile.
This paper does not attempt to describe CGM, which is fully described in the ISO Standard [1] and its two amendments [2] and [3]. The standard defines 3 versions of CGM which have different capabilities:
* Version 1 is the original 1992 standard,
* Version 2 added elements to support GKS, the most important was SEGMENTS.
* Version 3 added many new drawing primitives, including curves, and more colour models.
* Version 4 is defined in [3] and adds support for APPLICATION STRUCTURES.