COUNTERSURVEILLANCE: New scanner may prevent unauthorized digital photography

Soon, people who want to take photos surreptitiously may have to go back to using 35 mm film. Students under the direction of Gregory Abowd, an associate professor in the College of Computing at the Georgia Institute of Technology (Atlanta, GA), have created a prototype device to find and block hidden digital cameras. Commercial versions of the technology might eventually be used to foil unwanted use of video or still cameras.

The current prototype device, built using off-the-shelf equipment (camera-mounted sensors, lighting equipment, a projector, and a computer) uses visible light and two cameras to scan for and neutralize the CCDs in digital cameras. The system works by looking for the reflectivity and shape of image-producing sensors.

Because CCDs are retroreflective, they send light back directly to its origin rather than scattering it. Sensing these retroreflections would probably make possible easy detection and identification of video cameras in a darkened theater, according to the researchers. A future commercial camera-sensing system might use invisible IR lasers and photodetecting transistors to scan for contraband cameras. Once such a system found a suspicious spot, it would feed information on the reflection’s properties to the computer for a determination.

When a contraband digital camera was located and verified, the system would flash a thin beam of visible white light directly at the CCD. The beam-possibly a laser in a commercial version-would overwhelm the target camera with light, rendering recorded imagery unusable. The researchers say that energy levels used to neutralize cameras would be low enough to preclude any health risks to the operator.

“The biggest problem is making sure we don’t get false positives from, say, a large shiny earring,” said Summet. “We need to make our system work well enough so that it can find a dot, then test to see if it’s reflective, then see if it’s retroreflective, and then test to see if it’s the right shape.”

The camera-neutralizing technology shows commercial promise in two principal fields-protecting limited areas against clandestine photography and stopping video copying in larger areas such as theaters. The potential of camera neutralization has helped bring it under the wing of VentureLab, a Georgia Tech group that assists fledgling companies through the critical feasibility and first-funding phases. Operating under the name DominINC, Abowd’s company has already received a Phase 1 grant from the Georgia Research Alliance (GRA) with VentureLab assistance.