Video surveillance networks: Lights, camera, controversy

Advances in video surveillance technology lets Big Brother zoom in


     "Suppose mayor Smith's wife is filmed entering an abortion clinic, or Rev. Jones is recorded attending an AA meeting," he gives as an example. In the wrong hands sensitive information could be used illegitimately for political gain, to prevent employment opportunity or to deny insurance access.

     "Clear procedural guidelines and legislation are needed to address the usage, sharing and retention of video obtained in public places," Gilbert comments.

     The surveillance cart may be before the legal horse, but it hasn't stopped deployment of new video technology. Implementation of video networks often makes financial sense through consolidation of security functions.

     Security officer positions could be eliminated, for instance, by utilizing consolidating technologies that link feeds from separate building systems into one corporate-park system. Here a single controller monitors the entire complex, instead of each building having its own security staff.

     "Technology now permits the consolidation of all video feeds, while combining them with devices such as motion sensors," says Santo Scribani, CEO of ABM Security in Houston, Texas. "In essence, the need for security guard staffing is significantly reduced and replaced by technology and consolidation of technology."

Smart video

     The shift toward wireless IP-based surveillance systems has spawned more than cost reductions. The second major industry trend is the emergence of video analytics, or "intelligent video." This technology automates video monitoring with software that "watches" video feeds.

     Essentially, computers attempt to detect certain behaviors or scenarios — abandoned objects or lurking persons — then automatically alert security staff.

     Intelligent video is driven by increases in camera network complexity. As camera networks expand, it becomes increasingly difficult for security staff to effectively monitor all incoming video feeds. Intelligent video relieves the operator from the impossible chore of watching multiple monitors.

     "Computers never lose attention, so video analytics remedies this problem," Chambers says.

     Scribani says automatic software-based interactive alarms of event-based occurrences increase operator efficiency. Studies by Sandia National Labs have shown that security personnel are ineffective at video monitoring after only 15 minutes.

     Another driver is the heightened state of security necessitating increases in security.

     "Video analytics provide an effective first response mechanism, alerting law enforcement to possible problem behaviors in real time, possibly averting dangerous incidents," explains Chambers.

     Using advanced software, these systems are able to pick up subtle changes in monitored areas, such as identifying someone leaving a package as small as a paperback book or, conversely, detect whether something had been removed.

     However, system designers want more than just the ability to detect abandoned satchels. They want computers able to anticipate trouble by recognizing anomalies like suspicious behavior.

     Researchers at the University of Maryland, among others, are pursuing this goal. Electrical and computer engineering professor Rama Chellappa is designing intelligent surveillance systems that include recognition of human gait, faces and behaviors.

     Crunching data from surveillance cameras with sophisticated algorithms, Chellappa has developed a signature for characterizing human gait and corresponding activities, such as humans carrying objects like backpacks, handbags or briefcases.

     When a person's limbs are unencumbered, gait movements are symmetrical. Represented graphically, these movements form a twisted helical pattern resembling a "figure 8" that Chellappa says is slightly different in each individual. He calls it "human gait DNA."

     Since an individual's gait pattern is changed by any activity that changes the symmetry of the movements, for example carrying a package, by defining these signatures, the system may one day recognize unique patterns in human gait and automatically detect asymmetric movement, such as an individual walking with a hidden object tied to an ankle or wrist.

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