NCJ Number
224512
Journal
Law and Order: The Magazine for Police Management Volume: 56 Issue: 8 Dated: August 2008 Pages: 84-86,88-90,92
Date Published
August 2008
Length
7 pages
Annotation
This article reviews topics on license plate recognition (LPR) systems discussed in the December 2006 issue of “Law and Order,” and new developments in LPR and law enforcement’s application of the technology are detailed.
Abstract
LPR systems are composed of one or more infrared and color video cameras. They are typically mounted on the top or sides of patrol vehicles in nondescript black boxes. Each frame from the camera’s video is processed by a computer that “looks” for a license plate-sized object in the frame. If a plate is identified, it is analyzed by optical character recognition (OCR) software in order to determine its sequence of numbers and letters. This alphanumeric string is then compared against a database of “wanted” numbers. If the plate is not captured or if no “hit” is registered, the system disregards the information and proceeds to look for another plate. If a hit is registered, the officer is notified with an audible and/or visual alert. The entire LPR process is totally automated, requires no officer intervention, and takes less than a second to perform. Two years ago, buying an LPR system meant taking a leap of faith that the company and the technology would continue to work in the near future. Today those fears have been put to rest; only the efficient and effective manufacturers of LPR systems have survived. Innovative uses for LPR are being devised. One of the more interesting deployments is on school buses as a means of identifying drivers who risk the safety of entering and departing students when the “STOP” arm of the bus is extended. Along with new innovations and adaptations of LPR, the cost of the system is declining, which should expand its use by agencies.