Jochen Schneider and Thomas Strothotte
Otto-von-Guericke University of Magdeburg
Tactile maps constitute the media most commonly used by blind and partially sighted people for the exploration of spatial information. However, compared to maps for sighted people, they are inconvenient to produce and contain less information. We have developed methods and implemented them prototypically, by which visually impaired people can explore a geographical area flexibly with the help of a computer through virtual tactile maps. The design of a system is presented which captures hand positions through a video camera and produces acoustic output. It uses digital map data which is adapted to the requirements of the users. One of the most compelling problem is how to deal with the scale of a map, in particular the non-linearity of maps. In this paper, the development of the prototype and initial experience with it are presented.
A man, recognizable by the long white cane hanging from his arm as being blind, is standing on a sidewalk. He is holding his hands in front of him and moving them with concentration. He is in the middle of planning the rest of his walk through the down town area with the help of a virtual tactile map. He had explored the area and chosen a route through it at home. Now he is checking if he still remembers the rest of the route correctly. The man is wearing a baseball hat. There is a small camera in the screen of the hat, looking downwards at his hands and picking up their positions. The camera is connected to a small computer, which emits information through small earphones.
The scenario described is a vision. We report on the development of a system for the exploration of virtual tactile maps as a wearable computer (cf. Mann 1997). In this paper, the concept of virtual tactile maps and a prototypical implementation will be presented.