Monday, November 14, 2011

Automated License Plate Recognition

Automated License Plate Recognition, also known as ALPR, is one of the newest technologies to come available for police departments throughout the United States.  ALPR is a surveillance method that uses optical character recognition to read the license plates of vehicles (either parked in a parking lot or driving on an interstate).  In the United States ALPR is primarily used in the assistance of locating stolen vehicles, finding drivers with no insurance or suspended licenses, locating wanted persons, and even assisting with Amber Alerts.

How It Works

Recent changes in technology have made it possible to make ALPR mobile.  A mobile system is generally mounted on a patrol vehicle.  The cameras consist of infrared (IR) light emitting diode (LED) illumination, an infrared camera, and a color camera. Infrared illumination is used as almost all license plates are highly reflective to infrared which provides effective license plate image capture during day or night, and also eliminates the variability of plate backgrounds and colors by providing a clear monochrome image of the license plate.  The software algorithm identifies individual video frames containing a license plate image. The system will capture multiple images (one every 10-20 ms) of the plate as it passes through the field of view, with varying image capture settings with each picture to compensate for changing ambient conditions, plate-to-plate variability, and other variables. The cameras are very high speed, allowing for this process and effective image capture to take place at speeds of up to 160 mph.  The system automatically processes all pictures and cross matches it with a pre-loaded database of vehicle license plates.  If any suspicious vehicles are located, the officer is notified immediately on the Panasonic Toughbook or mobile data terminal mounted in their vehicle.  From there, the officer can follow appropriate protocol for their jurisdiction as the manner in which to proceed.

The Benefits

  • Efficiency - The average officer may check 50-100 plates during the course of their shift.  The ALPR can easily scan tens of thousands of plates in that same time frame.
  • Stolen Vehicle Recovery - Departments with ALPR statistically have significantly higher stolen vehicle recovery rates.
  • Officer Safety - Officers are aware of their surroundings and possible suspicious individuals prior to ever stepping out of their vehicle.  ALPR can be lifesaving during a traffic-stop.  
  • Elimination of Profiling Claims - Because the ALPR uses nothing but the license plate to alert the officer, it completely eliminates the suspects' claims that they were being profiled.
  • Increased Revenue - ALPR is instrumental in locating vehicles with outstanding parking violations and expired registrations, which leads to increased revenue.

ALPR In Action

Where To Get It
There are multiple companies throughout the world that specialize in the sales of ALPR.  One such company is NDI Recognition Systems.  NDI's US headquarters is located in Florida, however, they also have satellite offices in North Carolina and New Jersey. They are a primary dealer of ALPR software and peripherals in the United States.  NDI Recognition Systems sells the software that is being illustrated in the video.  They are the manufacturers of Veriplate, VISCE, and TALON.

How To Get It
With prices ranging upwards of $15,000-$20,000 per vehicle, most departments run into significant funding issues when they do decide to start adding ALPR systems to their fleet.  For many departments their only option is to request grant funding.  There are multiple federal grants that allow funds to be utilized for ALPR. They include: Edward Byrne Memorial (JAG) Program Grant, Byrne (JAG) Direct Grant, Project Safe Neighborhood Grant, and Comprehensive Approaches to Sex Offender Management Grant.


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