Tactile models based on video footage could make navigating a new city easier
Published: Jun 28, 2007
Researchers in Greece have developed a new system that converts video into virtual, touchable maps for the blind. The three-dimensional maps use force fields to represent walls and roads so the visually impaired can better understand the layout of buildings and cities.
“Imagine I’m blind and I want to come to New York,” says Konstantinos Moustakas, lead researcher on the virtual mapping project and a graduate student at Aristotle University of Thessaloníki in Greece. “I should have a map.”
Architects sometimes create three-dimensional models for the blind, but these replicas can only be used by one person at a time. Paper maps with ridges signifying roads are not ideal either, because they cannot convey enough information. With Moustakas’ system, a digital version of a diorama can be accessed simultaneously by people around the world. Extra information is presented in audio clips.
To build the virtual dioramas, the researchers first shoot video of an architectural model. The video is then processed frame by frame using software developed by Moustakas’ team. As the camera angle changes, the software tracks each structure and determines its shape and location. That data is used to create a three-dimensional grid of force fields for each structure. “Each point on the grid has an associated force value,” Moustakas says.
Two common-touch interfaces simulate the force fields by applying pressure to the user’s hand: the CyberGrasp glove, which pulls on individual fingers, and the Phantom Desktop, which applies a single force to the hand via a wand. Moustakas said the process is somewhat like trying to identify an object by running a finger or wand along its surface.
Virtual, touchable maps, also known as haptic maps, have been created before, but they were made using stereoscopic movies, which require special cameras. Moustakas’ system works with a standard video camera.
Moustakas also developed a system that converts pictures of traditional paper maps into a three-dimensional street map. Users run a finger or wand down the grooved roads of the virtual map, while street names are automatically read aloud.
Moustakas tested both systems on 19 visually impaired people. During the tests, subjects were asked to identify buildings in the virtual scene and travel from one location to another.
