Georgia Tech Device Disables Digital Cameras

There's technology that can prevent camera phones from snapping pictures in, say, locker rooms. But software has to be loaded onto the camera for the blocking feature to work. Gregory Abowd, a Georgia Tech associate professor of computer studies, decided to build a system that doesn't require the camera's cooperation.

Abowd's research team from the university's Interactive and Intelligent Computing division used off-the-shelf equipment to create a prototype system that can find and neutralize digital cameras. Abowd believes a commercial product could be available in a year. Look for the system to be deployed in laboratories, though, more than lavatories. Governments and companies could install anti-photography devices in labs and other installations to thwart spies. So might movie theaters, in order to prevent film piracy. The motion-picture industry claims it loses more than $3.5 billion a year to counterfeits created by fraudsters who sneak digital video cameras into theaters.

Overexposure
Abowd's system locates the offending device, then neutralizes it. Every digital camera has an image sensor known as a CCD, which is retroreflective and sends light back directly to its original source rather than scattering it. Retroreflections make it fairly easy to detect and identify digital cameras because they emit either a visible or an invisible beam of light. Once identified, the anti-camera system would beam an invisible infrared laser into the camera's lens, in effect overexposing the photo and rendering it useless. Low levels of energy neutralize cameras but are neither a health danger to operators nor a physical risk to cameras.

Abowd's prototype uses visible light and two cameras to find CCDs, but a commercial system would employ invisible infrared light as well as photo-detecting transistors.

There are limits to the Georgia Tech system. It can't detect certain cameras--single-lens-reflex cameras use a folding-mirror viewing mechanism that masks CCDs when no photo is being snapped, much like traditional film cameras. Abowd's group is working to overcome that problem. Another area of concern is that criminals could conceivably use the image-neutralizing system to disable security cameras. Abowd says the same technology can be used to secure surveillance cameras. Lest the evildoers read, he declined to reveal how such countermeasures would work.