Facial Scanning Is Making Gains in Surveillance
By Charlie Savage, NY Times, August 21, 2013
WASHINGTON—The federal government is making progress on developing a surveillance system that would pair computers with video cameras to scan crowds and automatically identify people by their faces, according to newly disclosed documents and interviews with researchers working on the project.
The Department of Homeland Security tested a crowd-scanning project called the Biometric Optical Surveillance System—or BOSS—last fall after two years of government-financed development. Although the system is not ready for use, researchers say they are making significant advances. That alarms privacy advocates, who say that now is the time for the government to establish oversight rules and limits on how it will someday be used.
There have been stabs for over a decade at building a system that would help match faces in a crowd with names on a watch list—whether in searching for terrorism suspects at high-profile events like a presidential inaugural parade, looking for criminal fugitives in places like Times Square or identifying card cheats in crowded casinos.
The automated matching of close-up photographs has improved greatly in recent years, and companies like Facebook have experimented with it using still pictures.
But even with advances in computer power, the technical hurdles involving crowd scans from a distance have proved to be far more challenging. Despite occasional much-hyped tests, including one as far back as the 2001 Super Bowl, technical specialists say crowd scanning is still too slow and unreliable.
The release of the documents about the government’s efforts to overcome those challenges comes amid a surge of interest in surveillance matters inspired by the leaks by Edward J. Snowden, the former National Security Agency contractor. Interest in video surveillance was also fueled by the attack on the Boston Marathon, where suspects were identified by officials looking through camera footage.
After a recent test of the system, the department recommended against deploying it until more improvements could be made. “I would say we’re at least five years off, but it all depends on what kind of goals they have in mind” for such a system, said Anil Jain, a specialist in computer vision and biometrics engineering at Michigan State University who was not involved in the BOSS project.
Significant progress is already being made in automated face recognition using photographs taken under ideal conditions, like passport pictures and mug shots. The Federal Bureau of Investigation is spending $1 billion to roll out a Next Generation Identification system that will provide a national mug shot database to help local police departments verify identities.
But surveillance of crowds from a distance—in which lighting and shadows vary, and faces tend to be partly obscured or pointed in random directions—is still not reliable or fast enough. The BOSS research is intended to overcome those challenges by generating far more information for computers to analyze.
The system consists of two towers bearing “robotic camera structures” with infrared and distance sensors. They take pictures of the same subject from slightly different angles. A computer then processes the images into a “3-D signature” built from data like the ratios between various points on someone’s face to be compared against data about faces stored in a watch-list database, the documents show.
In interviews, Ed Tivol of Electronic Warfare Associates suggested that as computer processing becomes ever faster the remaining obstacles will fall away.
Mr. Tivol said the goal was to provide a match with an 80 percent to 90 percent certainty from a range of up to 100 meters, something “that has never been done.” While the system continued to have problems with light and shading in some tests, he said, in others the goal had been achieved at closer distances. Farther away, he said, the accuracy has fallen to 60 percent to 70 percent.
"The results were increasingly positive," he said. There was a "significant improvement" in speed, too, he said. At first, it took the system six to eight minutes to process images, but it now takes under 30 seconds.
Ginger McCall, a privacy advocate who obtained the documents under the Freedom of Information Act and provided them to The New York Times, said the time was now—while such technology is still maturing and not yet deployed—to build in rules for how it may be used. (Ms. McCall was at the Electronic Privacy Information Center at the time of her information act request.)
"This technology is always billed as antiterrorism, but then it drifts into other applications," Ms. McCall said. "We need a real conversation about whether and how we want this technology to be used, and now is the time for that debate."