3-D virtual maps for the blind
According to Scientific American in "Virtual Maps for the Blind," Greek researchers have developed a system to convert videos into touchable maps for the blind. These 3-D haptic maps "use force fields to represent walls and roads so the visually impaired can better understand the layout of buildings and cities." The researchers also built a system which converts 2-D paper maps into 3-D street maps. The systems have already been tested on a small number of users. Now, the two systems need to be integrated into a portable device before being widely distributed.
These systems have been developed at the Informatics and Telematics Institute (ITI), located at the Aristotle University of Thessaloniki, by a team of researchers led by Konstantinos Moustakas.
Below is a diagram of a hardware prototype showing the integration of a Phantom Desktop, from SensAble Technologies, Inc. and a CyberGrasp from Immersion Corporation. This figure "presents the interconnection between the devices. The Phantom device is connected to the application PC via a parallel port. CyberGlove and CyberGrasp are connected to the CyberGrasp main unit via the Device Control Unit (DCU) and the Force Control Unit (FCU), respectively. Finally, the CyberGrasp main unit and the application PC are connected together using a 100Mbps Ethernet line." (Credit: ITI, Greece)
Here is how Scientific American compares Moustakas's maps with previous models built by other researchers.
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.
So how these maps are produced?
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.
This latest research work has been published by IEEE Multimedia under the name "Haptic Rendering of Visual Data for the Visually Impaired" (Volume 14, Number 1, Pages 62-72, January-March 2007). Here is a link to the abstract. For more information, you should read a previous paper published in the Proceedings of the 9-th International Conference 'Speech and Computer' (SPECOM'2004) St. Petersburg, September 2004, "CyberGrasp and PHANTOM Integration: Enhanced Haptic Access for Visually Impaired Users" (PDF format, 7 pages, 2.05 MB). The above illustration comes from this document.
And I hope this virtual mapping system will be available soon, even if I'm somewhat skeptical today. As notes Scientific American, even with these virtual maps, "blind users would still need a guide dog or cane to navigate potholes in the real world."
Sources: Rachel Ross, Scientific American, April 4, 2007; and various websites
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