System for recognizing the same vehicle at different times and places

• US 6,747,687 B1
• Filed: 01/11/2000
• Issued: 06/08/2004
• Est. Priority Date: 01/11/2000
• Status: Expired due to Term

• Current Assignee: Pulnix America Incorporated (JAI A/S)
• Original Assignee: Pulnix America Incorporated (JAI A/S)
• Inventors: Alves, James Francis
• Primary Examiner(s): An, Shawn S.
• Application Number:
  US09/481,131
• Time in Patent Office: 1,610 Days
• Field of Search: 348/148, 348/25, 348/156, 348/159, 348/143, 348/161, 340/932.2, 340/933, 340/937, 340/988, 340/984-990, 340/993, 340/995, 340/425, 382/104, 382/105
• US Class Current: 348/148
• CPC Class Codes: H04N 7/188 Capturing isolated or intermittent images triggered by the occurrence of a predetermined event, e.g. an object reaching a predetermined position signal generation from motion picture films H04N5/253

Abstract

In a vehicle time-of-entry and time-of-exit system, the passing of a vehicle through an entrance generates a “trigger-t0” signal. An entrance video camera provides realtime images of entering vehicles. The trigger-t0 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-t1” signal. An exit video camera 116 provides realtime images of exiting vehicles. The trigger-t1 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.

Claims

1. A system for recognizing a vehicle at different times and places comprising:

an entrance video camera for providing a first video image of an entering vehicle, said entrance video camera being automatically triggered by said entering vehicle without requiring any other action by said entering vehicle or its driver to have access to a designated area;

an exit video camera for providing a second video image of an exiting vehicle, said exit video camera being automatically triggered by said exiting vehicle without requiring any other action by said exiting vehicle without requiring any other action by said exiting vehicle or its driver to exit said area;

a memory device for electronically storing said first and second video images;

a first time-stamp associated with the entrance video camera for applying a time to said first video image representing the time when said entering vehicle entered said area;

a second time-stamp associated with the exit video camera for applying a time to said second video image representing the time when said entering vehicle exited said area;

a matcher connected to the memory device and for identifying when said entering vehicle in said first video image is the same vehicle as said exiting vehicle in said second video image, the matcher providing for a match of said vehicle in said first and second video images based on match information that includes at least one of vehicle color, trim, style, tires, wheel covers, collision damage or a combination thereof to distinguish individual vehicles and without requiring a complete reading of a license plate number;

a length-of-stay computer connected to the memory device and having access to the first and second time-stamps, and calculating the time duration said vehicle visited said area when the matcher provides said match information;

a vehicle detection tag (VDT) created from a time-stamped said first video image and comprising a distilled set of data artifacts representing a unique visual signature of said entering vehicle and discarding visual information not unique to said vehicle to limit required processing time and storage needs, the VDT being embedded in a message data packet transmitted to the matcher; and

a background processor for periodically reporting the operational health and status of the entrance and exit video cameras.

2. The system of claim 1, further comprising:

a database of unmatched VDT'"'"'s for representing vehicles that have entered but not exited said area.