Dimitrios Dakopoulos, Nikolaos
G.Bourbakis
IEEE Transaction on Systems, Man, and
Cybernetics – Part C: Applications and Reviews, Vol. 40, No.1, 2010
Summary
The
paper is describing different technologies for visually impaired people, trying
to make a comparison analysis on which system appears to be the most complete.
The systems are generally
categorized according on their objective: vision enhancement, vision
replacement and vision substitution, the paper focuses on this last aspect.
Vision substitution technologies are to be considered in three subcategories:
electronic travel aids, electronic orientation aids and position devices, the
authors focus mainly on the first ones without usage of GPS.
Echolocation appear to be
one of the first methods, it uses two ultrasonic sensors and converts the
information to stereo audible sound sent through earphones.
Navbelt is another system
using also ultrasonic sensors, creating a map of the angles and the distance of
any object within this angle, it has two modes, a guidance and an image mode.
Another method is vOICE,
for which images captured by a camera are converted into sound-mapping and
communicated through headphones, it has the advantage of being small, light and
relatively cheap.
The University of
Stuttgart Project is working using a sensor module with a detachable cane
cameras and a keyboard, all connected to a portable computer, a digital
compass, a 3D inclinator and a loudspeaker. The computer contains software for
color, distance and size detection and is able to work wirelessly, the main
issue is related to the fact that the technology still appears to have
limitations.
The FIU project is a sonar
and compass unit with six ultrasonic range sensors pointing in the six radial
directions and uses a 3D sound rendering machine for communicating to the user,
in this case the navigation speed appears to be slow.
The Virtual Acoustic Space
is a stuy performing a sound map environment consisting of two color
microcameras attached to the frme of some conventional eyeglasses, a processor
and headphone, it appears to be convenient for the size.
The Navigation Assistance
for Visually Impaired (NAVI) consists of a video camera, a single board
processing system, batteries and a vest; the idea behind is that humans focus
on objects that are in front of the center of vision and so it is important to
distinguish between background and obstacles, so the video uses a fuzzy learning
vector quantization neural network for classifying the pixels background, the
pixels are then enhanced and the background suppressed, finally information is
processed into left and right parts and transformed to stereo sound. The
university of Guelph proposed a project to convert vision information into a
tactile glove, where tactile vibration communicates to each finger, according
on where the obstacle is coming from.
Guidecan is also a project
in which a common cane for blind is enhanced with sensors (there are also
different commercial products going in this direction).
The Electon-Neural Vision
System has the characteristic of being able to communicate to the human through
neural stimulation, but its equipment has to hold in order to achieve results.
Other tactile systems have
been developed, such as Tactile Handle and Tactile Vision System, the first
requiring excessing training and no free-hand conditions.
Further own, Tyflos is a
system born in the mid-90s for integrating different technologies.
Key Concepts
Vision System for Vision
impaired people.
Key Results
No method appeared yet to
be satisfying free-hand, free ears, wearability and simplicity requirements.
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