What is ANPR anyway? Auto Number Plate Recognition. Many people do not immediately appreciate the significance of computers reading the text of a number plate out of an image. For humans it is simply a matter of viewing an image or video stream and quite naturally reading any information including number plates without any effort. It is actually much more challenging for computers to do, it takes a highly complicated sequence of technical steps involving thousands of calculations and algorithms. But never mind that because computers are really good at calculations and they do not suffer from fatigue, they can monitor video footage 24x7 without resting. Nevertheless, it is what can be done after the number plate text is extracted that is important. The text is usable data and computers can do many useful things with data. Some typical applications of ANPR are listed below.
Advanced CCTV Surveillance Most CCTV systems simply display the video and record it for possible review. When ANPR is added it reads all the detected number plates of vehicles passing through the cameras field of view and makes records of these events. Events contain at least the following data:- original video clip or images, the number plate, the date, the time, the camera location. Now you can search for a particular vehicle and instantly recall and display the event records. This is far more efficient than scrolling through CCTV footage and reading all the plates by eye. The data can also be used for other purposes like counting the total number of vehicles, the unique plate numbers, the frequency of each vehicle, route take and average speed etc.
Gated communities and access points One frequent usage of ANPR is to streamline traffic flows in gated communities, golf estates, business parks etc. Detected number plates are automatically checked against a list of known plates in a database and allowed to pass through the barrier area. All events are recorded as in the above paragraph, and an original image can be displayed for visual comparison. Only vehicles that are not known need to be challenged by security personnel making it efficient, convenient and secure.
Hotlists, repossession, stolen vehicles, hit-and-run In both the above applications (and almost every deployment) of ANPR, it is natural to maintain a hotlist of plates of interest. When a plate in the hotlist is detected certain preprogrammed actions can automatically be initiated. This can be a simple alert that pops up on screen. It can be more advanced like sending one or many SMS's to a list of cell phone number and perhaps even sending images and hotlist details to a control Centre. When a vehicle on the hotlist comes into the ANPR area then security managers and other interested parties can be notified right away and react accordingly.
Wharehouses, Weighbridges, Transport companies and Fleets Monitor and record arrivals and departures at depots and weighbridges. One can know the last detected time and location of vehicles and average speed between depots. Record all vehicles including visitors and the date and time they were on your premises.
InCar patrols The purpose is to drive in public areas and detect vehicles on wanted lists in real-time. There can be many reasons for a vehicle to be on such a list. For example - repossession by banks, stolen, outstanding fines, hit and run and so forth. Each vehicle is equipped with 2 or more cameras and a notebook pc. The operator starts the software application and then just drives around on public roads and parking areas. When it detects a plate that matches one on the list it reacts and notifies you in several possible ways. At the least it sounds an alarm and displays the found vehicle prominently on screen. If the patrol vehicle is properly equipped it can also send SMS's and email with/without attachments etc.using 3G. The app is capable of stamping overlays onto all footage - especially useful is GPS data if a GPS receiver is connected. Naturally it links with Google maps.
Paid Parking Areas Combining POS (Point of Sale) technology with ANPR makes for a very efficient and convenient parking system. Vehicles can be recorded, billed and processed in a very streamlined manner. In some highly automated cases vehicles can access and depart the parking area as and when necessary and the relevant parking account can be automatically debited for the calculated hours. A nice option is to allow vehicle owners to purchase parking time online.
TrendingComputer vision is becoming a part of our daily lives and can be used to fight crime. Wherever ANPR is deployed, for example in shopping areas, in patrol vehicles, in cash-transit vehicles etc., one technique is to examine the recorded footage around the time of crimes being committed. The ANPR software can identify patterns or trending of plates before and after the event. This can often lead to the rapid detection of suspicious vehicles.
OtherThere are many other possible applications for ANPR, please consult us for assistance with your own projects.