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produce colour images in the
dark. Both of these cornerstones
were surpassed during the last year
with the introduction of colour-
at-night Lightfinder technology.
Here, Moore's Law is really kick-
ing in with sensor development
and we can expect a lot of progress
in low light video. Also, as CMOS
sensor technologies evolve we now
have the ability to be almost as
light sensitive in 5MP cameras as
the human eye, and much more
light sensitive than the eye in
HDTV and VGA resolutions.
And then of course there is
the ability to see with absolutely
no light at all which no human
can do. For this we now have
professional-grade, all-digital
thermal network cameras that can
be integrated into an IP-based sur-
veillance system. Thermal cameras
can detect humans and objects in
complete darkness as well as poor
visibility conditions, and are no
longer just for military usage.
wdR
Wide dynamic range is another
hot issue related to the sensor and
image processing. The human eye
is said to have a contrast range
to 120 dB. If compared to the
best wide dynamic range network
cameras on the market, it's a dead
heat tie. However, when humans
try to see during constant contrast
change, the eyes will get very tired
and a headache is likely on the
horizon. So in the long run, and
especially when fighting direct
sunlight, the camera is better than
the human eye without even the
need to wear sunglasses.
Field of view
Now that we've covered resolution
and light sensitivity of the camera
vs. the eye, the next comparison
is with field of view and mechani-
cal speed. The eye has a field of
view of approximately 75-95° and
a pan-tilt speed of roughly 900°/
second. If we compare this with
current PTZ cameras, the human
In the world of IP video,
cameras are computers that can
see. When we talk of computers,
we talk of artificial intelligence.
We talk of memory. Today we can
compare an IP video system to the
human eye and the brain. While
there's no perfect calculation, the
whole eye is said to have a total
resolution of more than 100 meg-
apixels, but this is hardly usable
for surveillance and it's not the
actual resolution that our brain
(the VMS) computes.
While the eye wins outright for
overall resolution, one can argue
that the usable resolution of the
cornea or what the brain computes
at a given time can vary greatly,
but it can be roughly estimated
between 5-10 megapixels depend-
ing on the person's eyesight. Still,
given that lens technology is not
on par with the higher resolutions
in security cameras maxing out
around 5 megapixels for profes-
sional surveillance and that most
10-20MP cameras lack frame rate
and image quality around the
edges of the scene, it is a clear win
for the human eye.
Moore's Law
There's one main reason that
lenses are not keeping pace with
IP camera and sensor develop-
ment, and therefore the human
eye: Moore's Law. Unlike the IT
components inside a camera, opti-
cal components like the lens do
not follow Moore's Law. So while
lenses are taking longer to evolve,
IP camera developers are using the
ever-growing processing power in
the cameras to look beyond pure
resolution and improve overall
image clarity with better light
sensitivity.
Many of us suffer with poor
night vision. But unlike our eyes,
cameras have the ability to lever-
age IR wavelengths and produce
a black and white image at night.
Analogue held one final advantage
over IP regarding light sensitivity,
yet neither analogue nor IP could
terms used to describe both. Cam-
eras in surveillance were created to
see what we as humans couldn't.
Yet in the analogue CCTV world,
the comparisons stopped at seeing.
Since the invention of the first ana-
logue video camera, it was natural to
compare these devices to the human
eye. Focus, light sensitivity, iris, lens,
focal length, and aperture are all
voice of
the security market
The future of video
surveillance use your eyes!
There are some areas today where the IP camera
beats even our own human abilities, but there are
also qualities where a surveillance system will never
replace human intelligence or intuition. How do we
stack up today with our IP video devices, and where
will we fall behind in the future? Martin Gren at Axis
has the answers.
By Martin Gren, co-founder of Axis Communications