ANPR Systems & Architecture
Automatic Number Plate Recognition software finds number plates from IP Camera image streams and extracts and records the plate result with the associated metadata (typically, Camera ID / Lane#, Site ID, Time & Date).
It is standard to also capture an image or two that may have the time and date (and even the extracted plate details) embedded at the time of capture. Whilst any IP camera might work to some extent, you would be ill-advised to use just any old IP Camera if you need 24/7 high accuracy results (irrespective of any fantastic claims). Be wary of recognition accuracy claims.
We use ANPR for Security Alerts & Monitoring, Staff and Visitor Car Park Access Control, Retail Car Park Management, Vehicle Statistics, Marketing Applications and VIP Alerts. Many ANPR Systems are purchased without Application Software but instead send plate reads to a 3rd Party System. Many Facilities use ANPR for multiple applications.
ANPR Solutions that work for you
Based on current technology, ANPR systems fall into two broad categories
A. Intelligent Cameras, where the image sensor, illumination, processor and recognition software are all in the camera housing. Typically read results are sent over a network to a central processor where they are stored. Application software will make decisions based upon rules allowing access, car park counts, opening barriers and security alerts.
B. Central Processing where IP ANPR Camera streams are decoded and processed centrally on either a single ANPR PC / Processor / Server / Virtual Server.
The Application will also be managed centrally as ‘A’.
As with all things, there can be advantages and disadvantages with ANPR Technology options. Even from the same technology provider, recognition rates can vary between an Intelligent camera and a traditional PC based option.
No matter what you want to achieve with ANPR, once you start to get into your ANPR Project you will have questions that you will not have anticipated including reading International Plates, Private Plates, Counting Vehicles, Alarms on Plates of Interest and how best to deal with Staff who don’t want to play within the rules.
Apart from the technology, your site may need some tweaks to ensure that your ANPR System will work correctly.