Climate Chang
ALPR
e
Left: A good ALPR system can find the license plate in a very busy image
Above: An ALPR camera with integral IR illuminator from INEX/ZAMIR
lems are common to each. Today the deciding factor for
the road agency is how a particular system can meet the
demands of their project’s traffic volume, vehicle
speeds, the ability to stand up to a harsh environment,
and the cost to do each of these things effectively. The
ALPR supplier must also take into account the character-
istics of the license plates that will be encountered such
as stacked letters, poor choice of color and materials,
use of the same number/letter arrangement on plates
differentiated only by some logo, or perhaps difficult
lighting conditions or other on-site civil works chal-
lenges. The better technology suppliers today each
have their own ways of minimizing these problems.
Because of the wide variety of license plates issued
around the world, the accuracy achievable today varies
greatly depending on where, geographically, a given
ALPR system is in use. A system installed in Israel, as an
example, is dealing with a standard issue passenger
plate that has only numbers.
The task becomes only marginally more challenging
as you look around the European continent where the
plates are, certainly by US standards, as big as billboards
with very little in the way of confusing characters or syn-
taxes or even potentially confusing graphics. With few
exceptions, the acid test for all serious players is the
North American license plate with all its syntax varie-
ties, colorful displays, personalized formats and chal-
lenging font varieties. And within the boundaries of
North America some plates are more difficult than oth-
ers for some of today’s available technology.
Given those differences, does an ALPR supplier com-
peting for a system in Israel quote the accuracy they
have experienced on a stretch of, say, Interstate 95 on
A typical method of deploying an ALPR camera/illuminator
the eastern seaboard of the US? Probably not, nor would
www.thinkinghighways.com Thinking Highways Vol 4 No 1 41
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