W3C to mull vector graphics spec

The World Wide Web Consortium today agreed to evaluate a 2D vector graphics specification, the third such specification on its docket.

Vector markup language, or VML, is a text format for vector graphics. It joins precision graphics markup language, or PGML, which Adobe submitted to the W3C last month.

A third spec, submitted by the U.K.'s Council for the Central Laboratory of the Research Councils, is known as Schematic Graphics on the World Wide Web.

Web graphics come in different types and formats. They are either text or binary, and either bitmaps or vector-based.

A text format, such as HTML, is human-readable and therefore more easily integrated with other text-based elements in a Web page. A binary format, like Macromedia's Flash animation product, is not human-readable, but its smaller size makes it more easily transmitted over the Web.

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 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 television or monitor screens with varying resolutions, and greater ease in animating the image.

Companies backing the VML proposal said it was superior to PGML in the editing process, adding that the W3C could glean valuable aspects of PGML's delivery system in its final recommendation.

The VML spec was submitted by Autodesk, Hewlett-Packard, Macromedia, Microsoft, and Visio.

"The real advantage of PGML is as a delivery format," said Steve Sklepowich, product manager for platforms marketing at Microsoft. "But PGML was not designed to edit graphics. They're complementary formats, and they each bring value."

Tom Malloy, vice president of engineering at Adobe, was similarly upbeat about the prospects for a standard.

"There's a whole lot of commonality between the two proposals, and we expect to get a standard out of the process that's greater than the sum of the parts," he said.

Malloy agreed that PGML's strength was in delivery, or "precision graphics and presentation," while VML's strength was in editing flexibility.

Both VML and PGML are based on XML, or extensible markup language. XML is a metalanguage for defining other markup languages through a set of tags. In the case of a graphics language, those tags would be things like "<shape>," "<group>," or "<shape type>."

Sklepowich said the VML spec, based on the graphics engine in the Microsoft Office suite, would provide Web authors with a more flexible means of working with images.

"People have been looking for a format for vector graphics for a long time," he added. "This is one of the more significant specs proposed so far based on XML."

The W3C is a respected international consortium that issues recommendations on Web development standards. Their standards are widely adopted throughout the Net.