The W3C today unveiled a working draft of Scalable Vector Graphics and solicited public comment on it. SVG follows four previous vector graphics submissions that the W3C has been considering, and is the first to be written in pure XML, or Extensible Markup Language.
Vector graphics are more flexible than the common bitmaps that form most of the graphics on the Web. In contrast to bitmaps, which are shipped fully rendered and are defined pixel by pixel, vector graphics are composed of mathematical descriptions of curves and forms. This composition results in a more compact file, the ability to render the image to fit different screens with varying resolutions, and greater ease in animating the image.
Out of the chaos of the four competing submissions, the W3C hopes to create order with SVG.
"We've been discussing how to create a new specification that has all the right features, significantly improves the state of graphics on the Web, and can be finished and implemented sooner rather than later," said Chris Lilley, W3C graphics activity lead and chair of the SVG working group. "The other specifications are interesting and useful starting points, but they are not under further development at W3C."
The four submissions that SVG supplants and gleans features from are as follows:
Web Schematics, designed for making flow charts and other diagrams.
Precision Graphics Markup Language, or PGML, which is best suited to graphics such as bar charts, logos, and screen graphics like push buttons. Submitted by Adobe, PGML is based on the firm's PostScript and portable document format (PDF) standards.
Vector Markup Language, or VML, is a text format for vector graphics. A documentation of the internal graphics format in the yet-to-be-released Office 2000 suite from Microsoft, it integrates well with style sheets and facilitates the editing of images, according to backers.
DrawML resembles Web Schematics, except that it relies heavily on Java classes to lay out diagrams.
These four submissions and SVG were designed to fix a host of problems with Web graphics, Lilley said. The new format will make graphics searchable, compatible with style sheets, faster to download, better navigable by visually impaired users, and more faithfully printable.
SVG will be vendor-neutral and cross-platform, Lilley said. Written in XML, the format will be readable by any XML-enabled browser and compatible with the document object model (DOM).
SVG's proposed recommendation--the penultimate step in the W3C recommendation process--is slated for late summer.