Digitised technical drawings are typically presented and edited on standard PCs with appropriate software installed. However, blind and visually-challenged persons must access a user interface and presentation tool specially tailored for them.
The TeDUB project has overcome the limitations of existing technologies by creating an innovative, accessible system. The Image Interpreter analyses drawings semi-automatically or automatically using image processing and knowledge processing techniques.
The system is capable of analysing and presenting diagrams from a number of formally defined technical drawing domains, primarily electronic circuits, floor plans and software (UML) engineering drawings.
Diagrams enter the system, are processed and transformed to the internal format of the TeDUB system and accessed by the Diagram Navigator, which allows users to interact via a number of devices, including an ordinary keyboard for input and textual output, either accessed through a Braille device or a screen reader.
The system also offers navigation using a joystick and sound notifications. Users can choose between interfaces. For example, the 3D sound interface provides spatial information relating to the user's current position, which allows them to 'walk' around the diagram.
An evaluation took place in Ireland, Italy, The Netherlands and the UK involving 35 blind or partially-sighted participants, including students aged 16 to 30 following courses on computer science or informatics, and professionals aged 21 to 60, working as programmers, software consultants and university lecturers.
They were positive about how easy the system can be learned. They also liked the simple operation of the interface when using keyboard commands and the combination of different interfaces to operate the system, as well as how to access information.
TeDUB can be integrated into available screen readers, avoiding the need to recreate completely new software environments. It also solves a problem that has traditionally demanded the more laborious solution of manually creating tactile diagrams.
Project partners are extending the number of types of drawings the system can handle and plan to include business bar and pie charts found in standard business communications. Future plans include focusing on the educational domain, specifically e-learning content.
For more information on TeDUB, visit the project web site by clicking this link: http://www-agki.tzi.de/bv/projects/tedub.