Visually impaired people must use largely text-based Assistive Technologies to access the Web. The Web developers must understand how these technologies operate in order to create compatible contents, which must comply with the Web Content Accessibility Guidelines (WCAG) of the W3C/WAI (World Wide Web Consortium/Web Accessibility Initiative).

Some of the Assistive Technologies used are screen readers, magnification software and Braille display. These technologies offer partial alternatives to the graphical representation of information, such as graphs, 3D objects, and images. However, these representations contain a lot of information which cannot be easily interpreted by screen readers. They are commonly used by sighted people to present information or exchange ideas more effectively.

Traditionally, to present graphs and images to blind and visually impaired people, tactile diagrams are used. They can explore the diagrams through the touch sensation of their fingers. Touch or haptic sense is much more effective than speech or audio when exploring a graph. It is an active process in which blind people can have control rather than just being told by the description through speech. However, through extensive testing with blind computer users over several years and in different countries, it is known that presenting graphical images in tactile form to them is still problematic in the absence of informative annotations, though still preferable over speech and audio.

As haptic devices become commercially available, research has been conducted to apply them to the computer-generated graphs. In the previous Framework programme, research projects such as GRAB has investigated the use of haptic interfaces to allow blind people to have access to the 3D computer graphics. Other EU projects such as TIM have tried to present graphs by using Braille display and tactile boards. Other research projects have also investigated the use of multimodal interfaces to present 3D virtual environments to blind people.

Benefits of multimodal representation have been seen from the research findings of those projects. Therefore, the research effort in this project will be put on to the use of multimodal representation to make graphs, 3D objects and images accessible.

The specific objectives in this area include:

• Developing techniques that will convert existing non-accessible Web contents into accessible forms according to the user's need.
  
  
• Investigate multimodal representation for different contents, different applications and different user disabilities.
  
  
• Producing guidelines for creating multimodal representation and toolkits for developers to create accessible Web contents in general and images in particular.