a human, but it doesn't experience fatigue like a human would. What it does not do is tell you that there is a threat. That qualification has to be made by a human. It is an assistant, and given the magnitude and widespread deployment of CCTV and surveillance technology these days, it's simply an intractable problem to look at all that video manually."

While the system doesn't recognize a certain individual or identify a threat, it will recognize behavior it has been programmed to recognize and then alert someone. It's resilient to rain, wind and blowing debris but doesn't work in dark settings. It doesn't work well in extremely crowded conditions, when there's just too much movement.

"In airports, it's used for a very specific purpose: to monitor the exit lanes where you expect people to be going from the gate area to the terminal," Gagvani said, referring to the deployment of the technology at the Rapid City Regional Airport. "This technology works like a champ when you define specifically what you care about and not have it do 20 different things."

The system can be expanded to yield more or fewer alerts by being configured to respond to more or fewer behaviors or movements. "The trick is to balance false alarms versus true alarms," Gagvani said. "And to keep the false alarm rate as low as possible because if this is alarming all the time, you might as well just look at the video all the time."

Keeping the false alarms at fewer than 10 percent of the total alerts is the goal, he said. "A well run behavior recognition system should give you no more than 100 alerts a day."

A system includes the cameras, the cabling that brings the video back to the security center or wherever it's being viewed and the video processors.

A Safer Campus
At Johns Hopkins University, a state-of-the-art communications center houses the brains of 89 "smart" cameras positioned strategically around the campus, and the 14-member staff that monitor the cameras.

"They installed a fairly elaborate video surveillance and emergency communications system and put our video analytics functionality into it," said Cernium CEO Craig Chambers. "It's now their primary source of dispatching officers on campus based on potential threats or interesting situations."

When the system recognizes behavior that it's been programmed to read as unusual, it alerts a staff member by framing the scene with a yellow rectangle. Staff then decides whether to send campus police or not.

Since its deployment in March 2005, the system has alerted staff to numerous thefts in progress, vandalism, minor traffic accidents and helped catch an armed robber. Campus bike thefts dropped from 25, during the fall 2005 semester, to three in fall 2006. The total number of crimes reported on campus in 2003 was 536. That number grew to 703 in 2004 then dropped to 279 after the installation of the new system in 2005.

Looking Out
Though the goal at the 140-acre Johns Hopkins University campus is to reduce crime overall by honing in on specific behaviors, the Perceptrak system deployed at the Rapid City Regional Airport has one function: to "watch" over the safety checkpoint areas and make sure nobody bypasses security.

"All we're looking for is wrong-way motion, which is a simple application, but it's a tremendous labor savings," said Mason Short, executive director of the Rapid City Regional Airport. "There's nothing more irritating for me than to walk out into the checkpoint and see screeners sitting on their butts doing nothing other than making sure somebody doesn't walk through. It's a waste of labor and manpower."

Two of the three cameras used at the airport are configured to sense wrong-way motion, and the third is a monitor that allows for Internet access from virtually

Jim McKay, Justice and Public Safety Editor  |  Justice and Public Safety Editor