AN ORWELLIAN nightmare it may be to many of us, but CCTV is a boat full of holes to the organisations that pay for it. Writes Paul Marks in an article originally published in New Scientist. That's because the people
watching CCTV images back in the control rooms often have too many screens to monitor at once, and so may miss the criminal or antisocial
activities they are there to spot.
To the rescue of Big Brother's limited attention capabilities come Ulas Vural and Yusuf Akgul of the Gebze Institute of Technology in Turkey, who
have developed a gaze-tracking camera system that watches the eyeballs of CCTV operators as they work. It then automatically produces a summary of
the CCTV video sequences they have missed during their shift. "This increases the reliability of the surveillance system by giving a second chance
to the operator," the researchers write in the journal Pattern Recognition Letters (DOI: 10.1016/j.patrec.2009.03.002).
The system uses webcam-style cameras trained on the irises of the CCTV operators. From this, software works out where the operators are looking as
they stare at each monitor - and the areas they have not been paying attention to. From this it creates a video of what they missed, for them and
their bosses to watch at the end of their shift.
To make sure the summary can be watched as quickly as possible, Vural and Akgul have developed an algorithm that discards frames that show only the
background with no people or moving vehicles in them, to leave only a few key frames for each scene of interest. Vural says the system runs on a
standard PC and processes the images in real time, so the summary frames are ready to browse, like a fast-motion flip book, at the end of the shift.
Privacy campaigners may enjoy the irony if the gaze-tracking system comes to be regarded as intrusive by CCTV operators - who could fear that
employers will use it to dispense with their services if they consistently miss too much on-screen skulduggery.
The gaze-tracking system may well be regarded as intrusive by CCTV control-room staff
Mike Lynch, chief executive of Autonomy, a smart software company based in the UK that has created its own CCTV analysis algorithms, points out that
gaze does not prove that an operator is registering the action. "They may be looking but not seeing," he says.