Everything You Need to Know About Automatic Number Plate Recognition (ANPR)


ANPR or Automatic Number Plate Recognition is a system that uses optical character recognition for reading the number plates of vehicles.
And why are you reading about it on the Camba.tv blog? Because we can now install cameras that have ANPR functionality! Yes!

Tell me all about ANPR.

It was invented by the rather cool sounding Police Scientific Development Unit in the UK in 1976.


God knows how they even tried something like this on a bunch of typewriters.


Anyhow it took them a good twenty odd years – and a computer science revolution – to produce cameras and software that can automatically recognise number plates. Good for them!

How? How?

How does it work I hear you say? Full disclosure: I googled the answer but made the picture myself.

  1. Camera identifies a number plate (this is often done using an infrared beam that reflects off the plate.)
  2. Software takes the number plate, adjusts the brightness and contrast and then skews it accordingly so the numbers are “straight on”.
  3. The software then works out what each number is, and can pass this data to other programmes. The standardisation of number plate sizes and typefaces has greatly helped the accuracy of ANPR systems.



BUT like most technology, nobody cares how it works – we just want to see it in action!

Oh yes, tell me about some common uses of this technology.

The cameras are used by authorities around the world for things like:

  • Electronic toll collection (did you pay that M50 toll yet?)
  • Cataloguing the movements of cars for security and “expected journey time” signs
  • Measuring average speed over longer distances (the sneakiest most effective method of speed reduction – not in Ireland yet)
  • Monitoring petrol station forecourts for those who –ahem– forget to pay
  • Transport planning and traffic management system to understand the flow of vehicles through a city
m50 toll booth picture borroed from toll website

A trucker tries to escape a hefty toll by putting his rig in to “blurred” mode.

These cameras can be integrated with existing CCTV systems or they can be mounted on police cars (You haven’t LIVED until you watch Police, Camera, Action! on Sky One at dawn.)

For years, these cameras required cars to be in very specific areas (like a lane on a road, or squeezed through a very narrow gap in Dublin Airport’s carpark) and they used to cost mega bucks – however more recently, like most technology, they have come down in price and are now much more affordable.

You mean I can own my own ANPR system?

Yes, yes you can!

Camba.tv now sell cameras that have full ANPR functionality. You can log the registration number of every car that enters your premises, or you can add specific number plates to a white list or black list for automated functions like opening a barrier or calling the feds.

Here’s a sample of uses:

  • Car Parks: automatically open barrier; ensuring people aren’t over-staying their welcome; automatically notifying someone when a car enters or leaves; keeping records of who’s been arriving early or staying late.
  • Deliveries: Any business that receives or dispatches goods can have a number plate linked with each movement improving security and helping dispute resolution.
  • Apartment blocks: improve security at apartment blocks by registering every car that enters and leaves the property.
  • Rural homes & businesses: Know exactly who was in your yard and easily share pictures
  • Control freaks: know as much as you can about everything else with cameras.
  • Hotels owners: if you had a record of guest’s number plates, you could greet them by name as they step out of the car = a VIP first impression that would get you 5 star ratings.

creepy bell boy knows girl

And that’s only the things we could think of. Imagine how well you know your business and imagine how cameras could help you be more efficient/awesome/lazy?!

Get in touch today to discuss these things, we’re sitting by the phone patiently waiting: 01 538 3333 or email iloveanpr@camba.tv.