METHODS AND SYSTEMS FOR OPTIMIZED PARAMETER SELECTION IN AUTOMATED LICENSE PLATE RECOGNITION

• US 20130294653A1
• Filed: 05/07/2012
• Published: 11/07/2013
• Est. Priority Date: 05/07/2012
• Status: Active Grant

• Current Assignee: Conduent Business Services, LLC (Conduent, Inc.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Burry, Aaron Michael, Zhao, Yonghui, Kozitsky, Vladimir
• Granted Patent: US 9,292,759 B2
• Time in Patent Office: Days
• US Class Current: 382/105
• CPC Class Codes: G06V 20/625 License plates
• CPC Class Codes: G06V 20/63 Scene text, e.g. street names

Abstract

A system and method for automatically recognizing license plate information, the method comprising receiving an image of a license plate, and generating a plurality of image processing data sets, wherein each image processing data set of the plurality of image processing data sets is associated with a score of a plurality of scores by a scoring process comprising determining one or more image processing parameters, generating the image processing data set by processing the image using the one or more image processing parameters, generating the score based on the image processing data, and associating the image processing data set with the score.

Claims

1. A method for automatically recognizing license plate information, the method comprising:

receiving an image of a license plate; and

generating a plurality of image processing data sets, wherein each image processing data set of the plurality of image processing data sets is associated with a score of a plurality of scores by a scoring process comprising;

determining one or more image processing parameters;

generating the image processing data set by processing the image using the one or more image processing parameters;

generating the score based on the image processing data; and

associating the image processing data set with the score.

2. The method of claim 1, the method further comprising generating license plate data based on a preferred image processing data set of the plurality of image processing data sets, wherein the preferred image processing data set is associated with a highest score of the plurality of scores.

3. The method of claim 1, wherein processing the image using the one or more image processing parameters comprises performing binarization on the image.

4. The method of claim 1, wherein processing the image using the one or more image processing parameters comprises applying a tone reproduction curve to the image.

5. The method of claim 1, wherein processing the image using the one or more image processing parameters comprises applying a filter to the image.

6. The method of claim 1, the scoring process further comprising:

segmenting the image into a plurality of characters based on the image processing data set; and

wherein generating the score based on the image processing data comprises generating a segment score for each character of the plurality of characters.

7. The method of claim 6, wherein generating the segment score for each character of the plurality of characters comprises generating the segment score for each character of the plurality of characters using a connected component analysis.

8. The method of claim 1, wherein generating the score based on the image processing data comprises generating the score based on expected license plate information.

9. The method of claim 1, wherein generating the score based on the image processing data comprises generating the score based on an expected position of license plate information.

10. The method of claim 1, wherein determining the one or more image processing parameters comprises selecting the one or more image processing parameters from a predetermined set of one or more image processing parameters.

11. The method of claim 1, wherein determining the one or more image processing parameters comprises determining the one or more image processing parameters based a score associated with an image processing data set generated using a previous one or more image processing parameters.

12. A system configured for automatically recognizing license plate information, the system comprising:

a processing system comprising one or more processors; and

a memory system comprising one or more computer-readable media, wherein the one or more computer-readable media contain instructions that, when executed by the processing system, cause the processing system to perform operations comprising;

receiving an image of a license plate; and

generating a plurality of image processing data sets, wherein each image processing data set of the plurality of image processing data sets is associated with a score of a plurality of scores by a scoring process comprising;

determining one or more image processing parameters;

generating the image processing data set by processing the image using the one or more image processing parameters;

generating the score based on the image processing data; and

associating the image processing data set with the score.

13. The system of claim 12, the operations further comprising generating license plate data based on a preferred image processing data set of the plurality of image processing data sets, wherein the preferred image processing data set is associated with a highest score of the plurality of scores.

14. The system of claim 12, wherein processing the image using the one or more image processing parameters comprises performing binarization on the image.

15. The system of claim 12, the scoring process further comprising:

segmenting the image into a plurality of characters based on the image processing data set; and

wherein generating the score based on the image processing data comprises generating a segment score for each character of the plurality of characters.

16. The system of claim 15, wherein generating the segment score for each character of the plurality of characters comprises generating the segment score for each character of the plurality of characters using a connected component analysis.

17. The system of claim 12, wherein generating the score based on the image processing data comprises generating the score based on expected license plate information.

18. The system of claim 12, wherein generating the score based on the image processing data comprises generating the score based on an expected position of license plate information.

19. The system of claim 12, wherein determining the one or more image processing parameters comprises selecting the one or more image processing parameters from a predetermined set of one or more image processing parameters.

20. The system of claim 12, wherein determining the one or more image processing parameters comprises determining the one or more image processing parameters based a score associated with an image processing data set generated using a previous one or more image processing parameters.