On the roof or inside the vehicle? Both options of the ANPR camera placement have their pros and cons.
When it comes to innovation, in many countries police tend to be the followers rather than the pioneers. However, in recent years we have seen a remarkable increase of digitalization in the law enforcement. One of the most evident examples of the ever-increasing use of technology by the police is vehicles fitted with roof cameras, the numbers of which have been growing throughout Europe.
Automatic Number (License) Plate Reading (ANPR or ALPR) cameras, able to recognize number plates of passing vehicles, have proven to be one of the most useful modern technologies, helping to clarify car thefts and other crimes.
Technical limitations
The technology consists of two parts. The first is a camera fitted with an infrared illuminator to improve visibility at twilight and night, and the second is a software capable of “reading” the number plates from the captured image.
Conventional ANPR cameras are manufactured with an integrated infrared (IR) light. They have almost exclusively been installed on car roofs. If mounted inside the vehicle interior, a large part of the light spectrum is reflected or absorbed by the thermal glass.
However, apart from technical difficulties, some police representatives would appreciate, for various reasons, if the ANPR system could be installed inside the car interior. Some are concerned that the camera may get damaged or dirty, and others would like to also equip unmarked vehicles with the technology.
In the interior with no compromise
MOSY always listens to customer requirements and analyses how it can customize its solutions to meet specific needs. That is why MOSY responded to its clients’ desires and extended its portfolio to include an ANPR system that can be built into a police car interior.
The principle of the solution is that the infrared illumination is separated from the actual camera. In this case, the light-emitting diodes are fitted to the front end of the vehicle, thus avoiding undesired reflection or absorption of a part of the light spectrum. This allows the ANPR camera to be placed in the vehicle interior without compromising the accuracy of the number plate recognition compared to exterior camera solutions. This also eliminates any concerns about potential effects of IR radiation on human health.
Solutions based on needs and desires
Of course, installation inside the car is more discreet and the hardware is better protected against possible mechanical damage and exposure to the elements. On the other hand, it also has its limits. Although in terms of license plate recognition accuracy, it is a fully adequate alternative to exterior ANPRs, it is not suitable for all scenarios.
For example, if there is a need to use the camera system to scan both sides of the road, or possibly all around the police vehicle, which is useful, for instance, when checking vehicles at car parks. In such cases, the installation of the interior solution is problematic due to limited options for the IR illumination and side cameras positioning.
The interior ANPR is therefore not a substitute, but rather an alternative to traditional exterior camera systems. Contact our specialist for a consultation and a proposal of an optimal solution for your specific needs and requirements.
