Before making a considerable investment in an Automatic Number Plate Recognition system you will want to make sure you understand the implications. This piece is intended to give you a brief description of what is entailed. If you want more information we at 6S Global would like to help you, so get in touch.
Sensible questions to ask come under these broad headings:
Before venturing into ANPR you will need to consider what purposes you want it to achieve. Possible requirements could include notification to police and others about illegality, generating payment requests for access or parking, managing parking spaces, monitoring permitted and non-permitted access, barrier control, and preventing payment avoidance. Each of these and other purposes require a system specifically designed to fulfil them.
There are two elements to this question.
– What kind of hardware is required?
– What kind of software is needed?
Law enforcement agencies may require mobile vehicle-based systems; most private users will need fixed camera arrays. It is possible to utilise existing CCTV monitoring cameras, but better results will be possible with dedicated ANPR cameras. These will need to be supported by infra-red illumination for night-time use. This also reduces the amount of surface glare from the number plate, which affects the success of harvesting the number.
It is very wise to include the possibility of a human-readable image linked to the cameras, for subsequent checking and verifying of the ANPR camera. This could either be a separate feed from the camera or a parallel vision camera.
The software to process the information needs to be carefully selected. Often this will be a custom configured package incorporating the particular features required. Make sure the provider knows exactly what you need the ANPR to do, and get them to show how the software solves your problem. Is the software easy to use? What arrangements will there be for required updates?
The precise positioning of cameras is critical to achieving successful outcomes. They must be able to clearly see the registration plates of vehicles, either approaching or moving away from the camera point, without blockage by other vehicles. This is another reason that using dedicated cameras is likely to be more successful than utilising an existing set-up.
For best results, the angle of the camera to the line of vehicle travel should be as low as possible. If motorcycles are to be included the camera must be aligned to see vehicles moving away from rather than towards the camera.
How easy is the system to operate? Assuming busy traffic flows, you will need the system to reliably deliver monitoring and decisions, with minimum human assistance. If it is controlling a gate or barrier, what default arrangements are in place if it cannot give the correct output? If it is monitoring to send alerts for known offenders false readings should be very rare. How easy is it to maintain the decision database (with details of permitted and non-permitteds)? What is the process for human checking and verifying of the results, and what information needs to be captured for that, and how is it stored?
We at 6S Global have much expertise in this area. If We have put together a document giving guidance about commissioning ANPR systems, which you can read here.
As well the UK government has produced a document which offers advice and explores the various legal standards applicable to ANPR systems