Images became standard in nowadays information publishing. The information presented in images must be accessible to all people. Nearly all web pages of today use bitmap graphics, where the information is stored in pixel matrices. The next gerneration of graphics on the web will use vector graphics. In this kind of graphics the information is stored in XML-tags. The World Wide Web Consortium and the Web3D Consortium have recommended XML-based markup languages for different kind of areas of application:

• Mathematical expressions: Mathematical Markup Language (MathML)
• 2D-Graphics: Scalable Vector Graphics (SVG)
• 3D-Graphics: Extensible 3D (X3D)

XML-based graphics are scaleable, reusable and can be generated easily by a script. For users with visual disabilities it is possible to access this information with non-visual devices. To make this feasible the graphics have to be transformed in another representation.

MathML expressions can be transformed in a compact mathematical notation for the blind. There is a mathematical notation which has been developed in our group at the University of Stuttgart since 1980 called Stuttgart Mathematical Notation For the Blind (SMFB).

Mathematical expressions for sighted seers, visual representation and braille representation of SMFB

More details can be found in the following publication:

M. Rotard, K. Bosse, W. Schweikhardt, and T. Ertl.
Access to Mathematical Expressions in MathML for the Blind.
In Stephanidis, C., editor, Universal Access in HCI , volume 4, pages 1325-1329.
Lawrence Erlbaum Associates, 2003

Scalable Vector Graphics provide a great opportunity to explore graphical information on tactile devices. Text, shapes, attributes, and meta information of SVG can be extracted easily and an interactive exploration of the graphics is possible.

Business bar chart in SVG

Taktile representation of the SVG business bar chart

More details can be found in the following publication:

M. Rotard and T. Ertl.
Tactile Access to Scalable Vector Graphics for People with Visual Impairment.
In Proceedings of the SVG Open 2004 , 2004

Contact:
Martin Rotard
rotard(-AT-)vis.uni-stuttgart.de