Cameras to catch carpool lane cheaters
posted August 3rd 2004 4:06AM
It seems that the Brits are, unsurprisingly trying to save money in
their quest to ticket carpool lane cheaters. Actually having police do enough monitoring to act as a real deterrent is
pretty costly, so they decided to let a camera do the work. In pursuit of that goal, Laser Optical Engineering has
developed an infrared camera that exploits a small range of the infrared spectrum that is absorbed by human skin but
reflected by all the non-organic parts of a car. This camera will be combined with an image recognition software to
help eliminate the identification of other body parts as a second occupant, as well as shore up shoddy performance in
lower light conditions (read: anything but bright sunlight; which is reputed to in short supply in England, isn't it?).
We see a problem here, since windshields absorb infrared light, a "highly sophisticated – and vastly expensive" camera
would do the trick. And here we thought they were trying to save money.
It's not obvious from the article that carpool lanes don't actually exist in the UK - at least not yet.
The cameras will work if they operate in the shortwave infrared (SWIR) wavelength range from 0.9 to 1.7 µm. The visible spectrum ranges from 0.40 to 0.75 µm (blue to red). Traditionally, infrared refers to long wave infrared (heat) which is a much longer wavelength (7-11 µm).
Water reflects SWIR. Water in human skin reflects as well which is what these guys appear to be depending upon...