Spring/Summer 2006

RESEARCHERS AT the Georgia Institute of Technology have completed a prototype device that can block digital-camera function in a given area. Commercial versions of the technology could be used to stymie unwanted use of video or still cameras.

photo by Gary Meek A team of researchers in the Interactive and Intelligent Computing division of the Georgia Tech College of Computing has developed a prototype device that can block digital-camera function in a given area. Commercial versions of the technology could be used to stymie unwanted use of video or still cameras. Pictured, left to right, are Jay Summet, James Clawson, Gregory Abowd and Khai Truong.

The prototype device, produced by a team in the Interactive and Intelligent Computing division of the Georgia Tech College of Computing, uses off-the-shelf equipment – camera-mounted sensors, lighting equipment, a projector and a computer – to scan for, find and neutralize digital cameras. The system works by looking for the reflectivity and shape of the image-producing sensors used in digital cameras.

Gregory Abowd, an associate professor leading the project, says the new camera-neutralizing technology shows commercial promise in two principal fields – protecting limited areas against clandestine photography or stopping video copying in larger areas such as theaters.

“The prototype we have developed could lead to products for markets that have a small, critical area to protect,” Abowd says. “Then we’re also looking to do additional research that could increase the protected area for one of our more interesting clients, the motion picture industry.”

The small-area product could prevent espionage photography in government buildings, industrial settings or trade shows, Abowd notes. It also could be used in business settings – for instance, to stop amateur photography where shopping-mall-Santa pictures are being taken.

Meanwhile, preventing movie copying could be a major application for camera-blocking technology, says James Clawson, a research technician on Abowd’s prototype team.

“Movie piracy is a $3 billion-a-year problem,” Clawson adds. It’s a problem that is reportedly acute in Asia. “If someone videotapes a movie in a theater and then puts it up on the Web that night or burns half a million copies to sell on the street, then the movie industry has lost a lot of in-theater revenue.”

Moreover, movie theaters are likely to be a good setting for camera-blocking technology, says Jay Summet, a research assistant who is also working on the prototype. A camera’s image sensor – called a CCD – is “retroreflective,” which means it sends light back directly to its origin rather than scattering it. Retroreflections probably would make it relatively easy to detect and identify video cameras in a darkened theater.

The current prototype uses visible light and two cameras to find CCDs, but a future commercial system might use invisible infrared lasers and photo-detecting transistors to scan for contraband cameras. Once such a system found a suspicious spot, it would feed information on the reflection’s properties to a computer for a determination.

“The biggest problem is making sure we don’t get false positives from, say, a large shiny earring,” Summet adds. “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.”

Once a scanning laser and photodetector located a video camera, the system would flash a thin beam of visible white light directly at the CCD. This beam – possibly a laser in a commercial version – would overwhelm the target camera with light, rendering recorded video unusable. Energy levels used to neutralize cameras would be low enough to preclude any health risks, researchers note.

Still-camera neutralization in small areas also shows near-term commercial promise, Abowd says. Despite ambient light levels far higher than in a theater, still cameras at a trade show or a mall should be fairly easy to detect, he adds. That’s because image sensors in most cell phones and digital cameras are placed close to the lens, making them easier to spot than the deeper-set sensors of video cameras.

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 I grant from the Georgia Research Alliance (GRA) with VentureLab assistance.

Funding availability will likely decide which technology – small- or large-area – will be developed first, Abowd says. DominINC will apply soon for GRA Phase II money. Those funds would be used to aid anti-piracy product development, as would any funding coming from the film industry.

Other potential funding, from industry and elsewhere, would likely be used to develop anti-espionage, small-area applications.

Motion-picture groups are actively looking for technology to foil piracy, says Stephen Fleming, Georgia Tech’s chief commercialization officer. Movie distributors might even promote camera-neutralizing systems by refusing to send films to theaters that don’t install anti-piracy systems.

There are some caveats, Summet notes. Current camera-neutralizing technology may never work against single-lens-reflex cameras, which use a folding-mirror viewing system that effectively masks its CCD except when a photo is actually being taken. Moreover, anti-digital techniques don’t work on conventional film cameras because they have no image sensor.

Good computer analysis will be the heart of effective camera blocking, Summet says.

“Most of the major work that we have left involves algorithmic development,” he adds. “False positives will be eliminated by making a system with fast, efficient computing.”

Also involved in the camera-neutralizing project are Shwetak Patel, a College of Computing Ph.D. student; Khai Truong, a former Georgia Tech Ph.D. student who is now at the University of Toronto; and Kent Lyons, a post-doctoral researcher at the College of Computing. The researchers presented a paper on this technology at the Ubicomp 2005 conference in Tokyo, Japan, in September 2005.