CONNECTED COMMENT (31/05/05)
Before you don your hoody and pop down to the local shopping centre or
high street for a spot of yobbery or shop-lifting you might like to ponder the
following question: what do Renaissance painters, flying saucers and out of
favour saints have in common?
To save you guessing the common thread is cutting-edge CCTV video
surveillance. The flying saucer reference will become clearer in just a moment
but the connection between Big Brother keeping his beady eye on you, artists
like da Vinci and Holbein and disreputable saints requires some explaining…
It concerns a rather clever trick pioneered by the master painters.
Every so often they were commissioned to do a portrait of a saint or a woman
that for various reasons, the commissioner preferred not to be recognised.
Their solution was a technique known as Anamorphosis -- from Late Greek,
meaning to transform -- whereby the image was highly distorted making it
totally unrecognisable. However, when the painting is viewed in the reflection
of a curved or cylindrical mirror it regains its correct proportions and all is
That brings us back to CCTV and a new video surveillance camera that
bears a striking resemblance to a small flying saucer. It solves a
long-standing problem for the security and surveillance industry, namely
keeping watch over us in large busy areas like shops and commercial premises.
Until recently the only way to do that was to install multiple fixed cameras,
hopefully pointed at the places where mischief is most likely to occur. The
more flexible alternative is to mount cameras fitted with zoom lenses on
motorised ‘pan/tilt’ platforms (known in the trade as a pan/tilt/zoom or ‘PTZ’
Fixed camera and PTZ installations generally involve a compromise of
one sort or another, either requiring the CCTV operator to keep a close watch
on banks of monitors, or be sufficiently alert to point the camera in the right
direction at the right time. Potentially important events are frequently missed
because the operator is either looking at the wrong monitor, or in a daze,
bought about by ‘monitor fatigue’.
The new saucer camera, which can be either ceiling or wall mounted, has
a single ‘fisheye’ lens giving a full 360-degree hemispherical view of the
surrounding area. The resulting image is grossly distorted and all but useless
for observation purposes but this is the clever part. Advanced digital image
processing -- the equivalent of the painter’s curved mirror -- corrects the
distortion and displays any part of the fisheye view in its proper perspective
so that it is almost indistinguishable from the picture coming from a
conventional CCTV camera.
Normally this level of processing, and the fact that only a small
portion of the whole image is being displayed would result in a drastic loss of
definition but the manufacturers have thought of that. The camera uses a
high-resolution image sensor chip with between three and five times as many
pixels as a normal CCTV camera. Incidentally, the reason the camera is flying
saucer shaped, and covered in metal fins, is to dissipate heat the generated by
the hard working processing chips.
Nothing can escape the saucer’s all-seeing eye. It can generate fisheye
and panoramic views plus up to four simultaneous ‘virtual’ camera views from
any part of the fisheye image -- all together on one screen if required -- or
the operator can pick a single view and ‘steer’ the camera to move in for a
detailed close-up using an electronic PTZ system. A motion tracking facility
automatically locks on to movement and follows the subject or object wherever
it moves in the image area. In fact there is no need for an operator at all and
the camera can be programmed to ‘tour’ the image area, concentrating on entry
and exit points, monitoring for unexpected movement.
News that CCTV cameras are getting smaller and a lot smarter will come
as no surprise to most people but developments like this means there could
actually be fewer of them in future. However, villains, civil libertarians and
those made uncomfortable by saturation video surveillance have little
celebrate. In this case less means more, one strategically placed saucer can do
the work of half a dozen fixed cameras so not only is Big Brother watching you
closer than ever, now he’s got eyes in the back of his head…
Ó R. Maybury 2005 2705