A visually impaired person requires proper navigation as well as detailed
the surroundings while traveling. Scientists through out the world wanted
some device to solve this problem. One such invention, describes a camera
detection system for visually impaired persons where the user can identify
objects and independently navigate but he/she does not get a semantic or
qualitative description of the surroundings. Scientists have also developed
to serve the same purpose where the visually impaired person can identify
objects but cannot get the perception of the surroundings while traversing.
Prof. S Chaudhuri and his students of Department of Electrical Engineering
to develop a camera based device system for visually impaired persons which
a semantic description of the surroundings. It is economical and light
(head mounted) device for a visually impaired person and gives him/her
a semantic representation
of the surroundings traversed by him/her, i.e a verbal narration of the
surroundings.This helps the user to form an image of the neighboring vicinity.
Furthermore, this device can be expanded to a robot navigation system where
operator gets a
perception of the surroundings traversed by the robot.
The device is comprised of a cap adapted to be fitted on the head
of the user (if head mounted, else to be appropriately
worn), an image capturing means mounted on the cap, a computing platform
connected to the image capturing means, a
feature data store attached to the computing platform and an output
module connected to the computer module (Fig. 1).
The computing platform is comprised of a laptop PC. The images of the
surroundings are captured either by a non-calibrated
digital camera or an omni directional camera.
The feature data is
stored on a USB
drive or hard disk. The digital camera
takes the photographs of the images of
the surroundings of the user reflected on the outer surface of the
cap which is coated with reflective material like mercuric
oxide. The omni directional camera takes the images itself and
those are divided into several sectors. The laptop
PC extracts the color component of the images taken by the camera,
compares it with the reference feature and identifies
the corresponding neighboring object. A narrative description
associated with the identified feature is fed either to
the speakers or to a Braille board display. As a result the user
is enabled to perceive the surroundings traversed by him. When
this device was tested on a visually impaired person, the estimated description
of the surroundings matched with
the reality thereby establishing that the newly invented device
is precise and dependable.
Indian patent application no. 133/MUM/2006 Patent grant no. 225370
Inventors: S Chaudhuri, Rajashekhar, and A Prabhudesai