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.