Monday, July 30, 2007

Roadside Camera Counts People in your Car

Researchers over in the UK have developed a camera vision system that that automatically counts the number of people inside a vehicle. Such a system could be used to charge road tolls based upon the number of occupants, and monitor high-occupancy vehicle lanes.

Its inventor, John Tyrer of Loughborough University, UK, claims the system is 95% accurate. "The step-change technology is the ability to look inside a car and count people," Tyrer says.

Unlike previous systems that use cameras and computer algorithms to spot the number of faces through the windscreen of a car, the dtect system uses infrared light to detect human skin, and a computerized facial recognition system to double-check.

The system works by shining infrared light with a wavelength of about 1550 nanometres through the windscreen of the car. This is absorbed by the skin (does not dazzle occupants) creating a dark area on the reflected infrared image. Other materials, such as hair, upholstery and clothing simply reflect the infrared light. To make sure the dark patch is really a face the system then looks for light in the visible red portion of the spectrum. Human skin will produce a highly reflected shape that can be matched with the infrared image.

Finally, the system analyses the size and the shape of both images, to make sure it's looking at a face and another part of the human body

The Dtect system has been tested on the campus at Loughborough University, and also on the Forth Bridge in Scotland.

Source: New Scientist and Vehicle Occupancy Ltd