[Engineering Feature]
The Unblinking Eye
Smile for the camera. Intelligent video analysis can locate potential terrorists, detect suspicious objects, and even spot card cheats—all without a human operator.
San Francisco International Airport (SFO) is a hub for business travelers, vacationers, immigrants, stopover passengers, on-site workers—and a whole lot of suspicious-looking people. That's why it's not surprising to discover that the airport operates an extensive video surveillance system. What is surprising is how very smart the system is.
When it comes to video surveillance, people tend to imagine banks of sharp-eyed human observers endlessly scanning video screens for anything out of the ordinary. But that's not necessarily true anymore. Sophisticated video analysis technologies are rapidly replacing people as ever-vigilant sentinels.
"If you have a security guard looking at a monitor, he's probably going to look at it for 10, 20 minutes and then get bored and zone out," says Dilip Sarangan, a security analyst for Frost and Sullivan, a technology market research firm. "A computer never gets bored, and nothing goes unchecked."
By studying human behavior and automatically detecting the presence and absence of various objects in real time, intelligent video analysis promises enhanced security at an overall lower cost. "It's more of a proactive rather than a reactive approach to video surveillance," says T. Jeff Vining, a security industry analyst at Gartner, another technology research firm.
Government agencies and other organizations are scooping up intelligent video analysis products at an accelerating pace. Over a dozen firms now offer some form of the technology. The vendor pool includes companies like Vidient, Westec Interactive, and Visual Defence, all of which offer products that can survey a local area—indoors or outdoors—and spot anything out of the ordinary.
Intelligent video system sales are projected to grow from $60 million in 2005 to $400 million in 2012, Sarangan predicts. "It's heading into the business mainstream," he says.
SCANNING SFO More than 32 million passengers pass through San Francisco International Airport each year. Visually studying even a small percentage of this flood of humanity for quirks and behavior that might betray a sinister motive would require an army of human observers glued to video monitors. For a solution that would prove effective without financially crippling manpower costs, SFO turned to SmartCatch, an intelligent video analysis technology offered by Vidient.
SmartCatch works in conjunction with the airport's existing closed-circuit television (CCTV) systems to detect aberrant or suspicious behavior and distinguish those patterns of activity from normal activities (Fig. 1). When the behavior-based software spots an anomaly, it sends a video clip via a pager, laptop, cell phone, or other communications device to a responder, who can then investigate the situation.
"When we say ‘behavior,' we don't mean facial recognition or license plate reading. We're really talking about a combination of human and object behaviors," says Steve Goldberg, Vidient's CEO. In other words, the system looks for people and objects, such as suitcases or packages, that aren't in the right place or have lingered in a place for too long.
"So if you parked your car at the curb, where it's only supposed to be for dropoff, and the car doesn't move, it will alert security," says Michael McCarron, SFO's community affairs director. The system also can spot "human tailgating," when two people pass through a secure door on a single ID card swipe, as well as things like crowd formation and people going through an exit lane the wrong way.
Vidient's Windows-based technology is based on sophisticated video algorithms developed over three years by NEC's computer vision engineers. "The algorithms are generally based on adaptive filtering or adaptive processing—neural network types that have been used in other data and voice applications," says Goldberg. SmartCatch detects suspicious situations with an accuracy rate between 95% and 98%, Goldberg notes.
Like most other intelligent video analysis technologies, Vidient's product functions by seeing each image as a mosaic of pixels. The algorithms then work to make sense out of the mosaic's movement, or lack of movement, and to separate the pixel cluster from background clutter. "Basically, video analytics is all software," Sarangan says.
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