Automatic number plate recognition system

• US 20050029347A1
• Filed: 03/22/2002
• Published: 02/10/2005
• Est. Priority Date: 03/28/2001
• Status: Abandoned Application

• Current Assignee: CitySync Limited (Tagmaster AB)
• Original Assignee: CitySync Limited (Tagmaster AB)
• Inventors: Bekooy, Nico, Noble, Lawson John, Thomson, Frank James
• Application Number:
  US10/473,381
• Publication Number:
  US 20050029347A1
• Time in Patent Office: Days
• US Class Current: 235/384
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 20/63 Scene text, e.g. street names
• CPC Class Codes: G07B 15/02 taking into account a variable factor such as distance or time, e.g. for passenger transport, parking systems or car rental systems G07B15/06 takes precedence; taximeters G07B13/00; parking meters per se G07F17/24; car rental systems per se G07B15/00
• CPC Class Codes: G08G 1/017 identifying vehicles G08G1/015, G08G1/054 take precedence

Abstract

A handheld automatic number plate recognition system comprising a handheld personal computer and a camera, the camera being operable to capture images and the computer including a processor to identify a number plate from an image captured by the camera.

Claims

1. A handheld automatic number plate recognition system comprising a handheld personal computer and a camera, the camera being operable to capture images and the computer comprising a processor to identify a number plate from an image captured by the camera, wherein the processor comprises means to identify rectangular areas, each such identified area comprising a possible number plate to be interpreted.

2. A system according to claim 1, wherein the computer is operable to interpret the image of the plate and output a string of recognized characters in response thereto.

3. A system according to claim 1 or 2, wherein the computer is operable to power down the camera when not in use.

4. A system according to any preceding claim, wherein the processor includes means to identify rectangular areas, each such identified area comprising a possible number plate to be interpreted.

5. A system according to any preceding claim, wherein the processor sets a plate size threshold range outside of which a captured image will not be processed.

6. A system according to claim 5, wherein the threshold range is between 1,000 and 10,000 pixels.

7. A system according to claim 6, wherein the threshold range is between 1,800 and 5,000 pixels.

8. A system according to any preceding claim, wherein the computer has a memory in which is stored a plurality of known number plates.

9. A system according to any preceding claim, wherein the system is portable.

10. A system according to any preceding claim, wherein the camera is attached to the computer.

11. A system according to any preceding claim, wherein a single housing holds the camera and the computer.

12. A system according to any preceding claim, wherein the computer includes a display operable to indicate a recognized number plate.

13. A system according to any preceding claim, wherein the computer includes a speaker and a synthesizer to enunciate the characters making up a recognized number plate.

14. A system according to any preceding claim, wherein the camera is operable in the infrared spectrum and the system has at least one infrared source.

15. A system according to claim 14, wherein the or each infrared source is located adjacent the camera such that a path of incident light from the infrared source is within 5°

of a return path of light reflected from a subject.

16-25. -25. (Canceled).