System for recognizing the same vehicle at different times and places

Abstract

In a vehicle time-of-entry and time-of-exit system, the passing of a vehicle through an entrance generates a “trigger-t ” signal. An entrance video camera provides realtime images of entering vehicles. The trigger-t signal causes one video frame of the image of vehicle to be stored or “frame-grabbed” in an entrance subsystem. A time-of-entry clock-time signal is used to time-stamp the image which is then forwarded on a connection to a matcher. The passing of a vehicle through an exit generates a “trigger-t ” signal. An exit video camera provides realtime images of exiting vehicles. The trigger-t signal causes one video frame of the image of vehicle to be stored or “frame-grabbed” in an exit subsystem. A clock-time signal is used to time-stamp the image which is then forwarded on a connection to the matcher. A output automatically provides a length-of-stay for each exiting vehicle according to its time-of-entry. The matcher uses the unique characteristics in the images of the vehicles to declare a match. While a license plate number is unique, reading any or all of a license plate is not necessary for the extraction of visual signatures related to particular cars. For example, in the limited variety of cars that would patronize a particular parking lot, the color, trim, style, tires, wheelcovers, collision damage, etc., of each vehicle can be used in combination to distinguish individual ones.