2-D Vector Graphics Come to the Internet

As more organizations deliver information via the World Wide Web, the lack of a standard vector format to represent technical illustrations is becoming acute. As the Web's raster formats, GIF and JPEG are excellent for displaying color images but inadequate for representing CAD drawings because zooming and resizing make the pictures jagged, blurry, and out of focus.

Chances are good that the Computer Graphics Metafile (CGM) format will fill this gap. CGM is a 2-D graphics format, standardized by the ISO, that is widely used in Standard Generalized Markup Language (SGML) documentation. Because it is a vector format, it scales without losing detail. Even more intriguing is CGM's capability to combine hot-spot links wit h single graph ical objects of a drawing. CGM hot-spot links enable a user to click on a certain part of a drawing to invoke, for example, a more detailed description of the part.

The National Institute of Standards and Technology, a U.S. member of the Web committee, implemented CGM in the National Center for Supercomputing Applications (NCSA) Mosaic source code early this year. This means that companies can include CGM drawings in Hypertext Markup Language (HTML) documentation, and the drawings will appear in-line when Mosaic displays them. Ematek Informatik (Cologne, Gemany) and HSI (Boulder, CO) jointly developed Mosaic's CGM filter. Other browsers will support CGM soon, according to Ematek.

Many industries will benefit from a standard 2-D vector format on the Web. Remote access to CAD drawings in technical documentation, for example, promises to make distant maintenance much easier.