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How Does ANPR for Gates Work? (Simple Guide)

Elliot Blackler July 13, 2021 8 min read

Using technology to help both the user and the company deploying is nothing new. In fact, it is the crux of why we develop new software and devices. 

Security can often be seen as fairly one sided, but this is entirely inaccurate, it keeps everyone safer and keeps a more secure environment.

Automatic Number Plate Recognition (ANPR) is a form of car management technology that can be part of a wider parking management system that is designed to help oversee parking in a location.

In this guide, we will be looking at ANPR camera technology, breaking it down into easy to understand areas and answering some ANPR FAQs. We will also be looking at the benefits of this technology and how it works.

In sum, we'll be covering: 

  • ANPR Basics
  • Features of ANPR for Gates
  • How to Work ANPR for Gates
  • ANPR Benefits 
  • Industries That Can Use ANPR for Gates
  • ANPR Summary

Short on time? Download our Nortech ANPR Comparison

What is ANPR?

ANPR or Automatic Number Plate Recognition is pretty much what it says on the tin. ANPR is a technology that reads number plates via a camera and transmits the data to the system.

Depending on the reader model, number plates can be read in a range of weather conditions and speeds up to, and above, 100 miles per hour. 

This technology can be deployed anywhere you want to keep track of cars coming in and out of a location, but you have probably seen it utilised in car parks in various locations.

If you have ever been leaving a car park and go to put your ticket in the machine and the gate automatically goes up, this is ANPR. The machine has recognised your plate, acknowledging you have already paid and allowing you to exit quicker.

ANPR is referred to as different things around the world, one of the common other names is Automatic License Plate Recognition (ALPR) in the US and Canada, due to the plates on vehicles referred to as license plates, not number plates.


Key Components of ANPR

The ANPR systems are fairly easy to understand, but let us look at what makes up this technology and what is required for it to work.

To keep it simple, there are three major parts to an Automatic Number Plate Recognition system; cameras, gates and the database or software.

Cameras - these devices are set up next to the gates and will scan approaching vehicles’ licence plates, either to grant entry to pre-authorised vehicles or to scan new plates.

ANPR Lumo PDF Comparison

Gates - directly linked to the cameras, the gates will open when all criteria has been met. This can be a recognised plate or allowing a new vehicle entry, this depends on where and how the technology is being used.

Management Software - this is the database where the information is stored, and how you can control who has access and who does not.

Obviously, this differs depending on how you apply your ANPR, a car park for instance tracks who has paid, a company car park would track employee plates.


How Does ANPR Work?

Automatic License Plate Recognition cameras can be used in a wide variety of settings from car parks to company offices, to police vehicle checks, but how do they work?

ANPR technology basically reads a registration plate when the vehicle is within its scan radius and will either enter it into a database or scan it against the records. 

This depends on where it is being deployed, a car park will scan new vehicles, whereas a company’s headquarters may only let pre-authorised vehicles in.

ANPR Systems can work in two different ways, to oversimplify, they can capture either:

  • Still Images - either one or a series of images to recognise a vehicle
  • Video Clips - short video footage to help recognise the plate quickly and effectively

Some of this technology uses Optical Character Recognition (OCR) which basically allows the cameras to digitally read and extract the alphanumeric characters from the digital footage.

The 7 Algorithms of Plate Reading 

ANPR software has to be able to recognise and correctly determine license plates from different regions and countries around the world, ANPR systems will typically have 7 algorithms embedded in the software to help read plates.

  1. Plate Localisation - how the system finds where the plate is on a photo or video footage.
  2. Orientation & Sizing - this allows the image to be adjusted to read the plate easier.
  3. Normalisation - editing the settings of the picture (such as brightness and contrast) to keep images consistent.
  4. Character Segmentation - this keeps the different characters separate for ease of reading the plate.
  5. OCR - Optical Character Recognition determines what each alphanumeric character is and converts them into textual data.
  6. Geometrical Analysis - checks the data against different countries and regions across the world and their license styles and patterns.
  7. Recognised Values - the previous algorithms are cross compared to ensure the information is correct, giving the best end result, accounting for lighting, weather and blur.

What are the Benefits of ANPR for Gates?

Automatic Number Plate Recognition technology has a wide variety of benefits that can be attributed to it, so we will be covering two core areas. Operational and User Benefits, so how it affects the end user and how it impacts your business.

These benefits will be fairly universal so they can be applied to most uses of an ANPR system and would affect most companies using them.

Operational Benefits

Easy Management 

One of the major concerns companies have when deploying new technology or systems is the ease of installation or the ability to manage it post-implementation. ANPR systems are seen as an hands-off approach to vehicle access control.

ANPR technology is managed by a database that is typically very user friendly and designed to be used by any skill level, with simple settings and features to customise the experience. 


Available Around the Clock 

Having an automated system gives you the flexibility to control and manage your locations around the clock. As opposed to a security team, a machine is cheaper and does not need to worry about shift times or breaks. 

This gives you the option to have a 24/7 operation that is secure at any time. In addition, the majority, if not all, of ANPR systems are designed for any weather and lighting conditions so work whenever you need them to.


Near Perfect Accuracy 

Higher end ANPR systems vary between 95-100% accuracy rate depending on which one you get, but will often be nearer the upper end of these percentages. 

The only times the information may truly be skewed is when something is blocking the camera or the plate, such as debris, dirt, or dust.


Improved Security 

ANPR for gate systems give you an added layer of location management and with this, an improved overall security infrastructure.

On certain systems, additional features range from a form of red flag list that tells you when a vehicle you have pre-flagged is scanned. This could be unauthorised vehicles or persistent criminals.

User Benefits 

Speeds Up User Experience 

Finding ways to benefit your users is an additional benefit when installing a new security or management measure. Having an ANPR system allows for a smooth and easy user experience.

Let us put this into context, the gate may automatically recognise a car and let the driver out of a gate as they drive up, saving the user valuable time.


No Learning Curve

Normally, reluctance to embrace new technology stems from the time or effort it takes to learn how to use it. This is where Automatic Number Plate Recognition comes into its own, there is no learning curve for users, as the name suggests, it’s automatic.

When implementing new methods or procedures it is always important to consider the end user, in this case, the drivers. Choosing technology that benefits both you and them creates a much higher approval rate.


Physical Barrier 

As a driver, we are frequently concerned about where we leave our vehicles and the security of an area we disembark our car. This acts as a form of deterrent for unauthorised people and vehicles.

Having an ANPR system that is linked to a gate means visitors and drivers can be more comfortable knowing only authorised vehicles and persons are allowed on the premises.



As we have alluded to above, the fact that ANPR is automated makes it useful for drivers and creates a seamless experience for them. Automation means that any time the driver needs to access a gate or area they can get in without human intervention.

This directly links to the operational benefit of not having to staff the gates around the clock and allows everyone access when they need it.


What Industries Can Benefit From ANPR Gate Systems?

Below are a few examples of the kind of places that either already use this technology or would benefit from its implementation in the near future.

  • Freeports and Storage Facilities
  • Police
  • Prisons
  • Hospitals  
  • Company Car Parks
  • Security 
  • Private Car Parks
  • Fleet Management 
  • Holiday Parks and Caravan Sites
  • Gyms, Health Clubs, and Sport Centres
  • Contract Parking
  • Hotels
  • Distribution Centres

The ANPR Industry

Automatic Number Plate technology has come on leaps and bounds from its humble beginnings in the late 70s. 

One of the biggest changes for the industry as a whole was in the 90s where the technology was deployed in more mobile systems, this is where police forces started to implement the technology.

We may not have even realised that we have been scanned by this technology or even used it last time we went to a car park or the airport. But, ANPR is prevalent in a wide range of industries.

As Automatic Number Plate Recognition technology gets more common we will see the technology evolve and shape the way we secure our locations and manage our vehicles.

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Why Should You Trust Us?

It seems that people and vehicle access control is an incredibly complex world using hard to understand technology, yet it impacts so many of the environments we interact with on a daily basis.

We are here to fill in the disconnect. We'll break down access control, the benefits, and drawbacks as well, including expert insight based on over 30 years experience in the industry operating as an independent British company. Our goal is to give you ALL the information so you know what's right for you.

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Elliot Blackler

Elliot is the in-house content specialist at Nortech and runs all aspects of the resource hub. He's passionate about UK manufacturing and how modern content marketing can help bring light to complex industries.

Elliot works extensively with the Nortech team to shine a light on the access control industry for both installers and end users. Always keen to improve, feel free to email him on new content suggestions or feedback!

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