QR CODE DETECTION

• US 20110290882A1
• Filed: 05/28/2010
• Published: 12/01/2011
• Est. Priority Date: 05/28/2010
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Gu, Zhiwei, Tien, Jonathan Y., Scott, Matthew R., Chen, Gang
• Application Number:
  US12/790,125
• Publication Number:
  US 20110290882A1
• Time in Patent Office: Days
• US Class Current: 235/462.11
• CPC Class Codes: G06K 7/1456 determining the orientation of the optical code with respect to the reader and correcting therefore

Abstract

One or more techniques and/or systems are disclosed for detecting a quick response (QR) code. An area of an image comprising a QR code is localized by combining pixel dynamic scale (DS), black-cell ratio (BR), and edge intensity sum (EIS) criteria determination to identify the QR code. A pattern for the QR code is detected, comprising determining if a position detection pattern (PDP) is located in respective grid areas of a first grid that comprises the QR code, and identifying an alignment pattern (AP), if present. To identify the AP, an AP region is estimated using the PDPs, and a center area of the AP is found by examining respective areas of a second grid comprising the estimated AP region.

Claims

1. A computer-based method for detecting a quick response (QR) code, comprising:

localizing an area of an image comprising a QR code by using a computer-based processor to combine pixel dynamic scale (DS), black-cell ratio (BR), and edge intensity sum (EIS) criteria determination to identify the QR code; and

detecting a pattern for the QR code comprising;

determining whether a position detection pattern (PDP) is located in respective areas of a first grid comprising the QR code; and

identifying an alignment pattern (AP), if present, comprising;

estimating an AP region using the PDPs; and

finding a center area of the AP by examining respective areas of a second grid comprising the estimated AP region.

2. The method of claim 1, localizing the area of the image comprising:

determining if a selected area of the image comprises a QR code;

extracting a QR code area comprising the QR code if present; and

verifying the extracted QR code area comprises dimensional parameters that are within a desired range for QR code detection.

3. The method of claim 2, determining criteria, comprising:

selecting a DS for a grayscale histogram of the image that mitigates noise;

calculating the BR by counting a number of black cells in the selected area; and

evaluating an edge gradient in the selected area to determine the EIS.

4. The method of claim 2, determining if the selected area of the image comprises a QR code comprising determining if the DS, BR and EIS criteria meet respective desired thresholds for the QR code area.

5. The method of claim 2, extracting the QR code area comprising extracting a QR code bounding area, comprising:

dividing the selected area into a third grid;

evaluating respective third grid boxes by comparing the EIS to a desired threshold; and

expanding the bounding area to comprise the QR code based on the evaluation of the third grid boxes.

6. The method of claim 1, detecting a pattern for the QR code comprising dividing a QR code bounding area into the first grid comprising a three by three grid of squares of a same size.

7. The method of claim 6, determining whether a PDP is located in respective areas of the first grid comprising scanning the respective first grid squares in a desired sequence that provides a least number of first grid square scans to identify the PDPs for the QR code.

8. The method of claim 6, scanning the first grid square comprising:

determining contrasted color segment lengths of the square along one or more scan lines that dissect the grid square; and

comparing the contrasted color segment lengths for the scan line with a desired threshold for a PDP.

9. The method of claim 6, comprising identifying the PDP center area, comprising:

comparing scan lines that dissect the grid square at a plurality of locations to a desired threshold for the PDP; and

estimating the PDP center area based on the results of the plurality of scan lines across the grid square.

10. The method of claim 1, estimating an AP region using the PDPs comprising selecting a region in a corner of the QR code that does not comprise a PDP.

11. The method of claim 1, identifying an AP comprising dividing the estimated AP region into the second grid comprising a three by three grid of squares of a same size.

12. The method of claim 1, finding a center area of the AP by examining respective areas of a second grid comprising scanning the respective first grid squares in a desired sequence that provides a least number of second grid square scans to identify the AP center area.

13. The method of claim 12, comprising scanning the second grid square comprising:

determining contrasted color segment lengths of the square along one or more scan lines that dissect the second grid square; and

comparing the contrasted color segment lengths for the scan line with a desired threshold for the AP.

14. The method of claim 12, comprising identifying the AP center area, comprising:

comparing scan lines that dissect the second grid square at a plurality of locations to a desired threshold for the AP; and

estimating the AP center area based on the results of the plurality of scan lines across the second grid square.

15. The method of claim 1, comprising binarizing the area of the image comprising the QR code.

16. A system for detecting a quick response (QR) code, comprising:

a computer-based memory component configured to store an image comprising a QR code;

a localization component operably coupled with the memory component and configured to identify an area of the image that comprises the QR code by using a combination of determined criteria, the criteria comprising;

pixel dynamic scale (DS);

black-cell ratio (BR); and

edge intensity sum (EIS);

a pattern detection component operably coupled with the memory component and configured to detect a pattern position for the QR code, comprising;

a position detection pattern (PDP) determination component configured to determine a location of a PDP located in the QR code by scanning respective areas of a first grid comprising the QR code; and

an alignment pattern (AP) determination component configured to determine a location of an AP in the QR code, if present, by examining respective areas of a second grid comprising an estimated AP region, estimated from the PDPs, to find a center area of the AP.

17. The system of claim 16, comprising an extraction component configured to extract the identified area of the image that comprises the QR code comprising a QR code bounding area determination component configured to identify a bounding area of the image that comprises a smallest area that bounds the QR code.

18. The system of claim 16, the PDP determination component comprising a scan line determination component configured to:

determine contrasted color segment lengths of a first grid square along one or more scan lines that dissect the first grid square; and

compare the contrasted color segment lengths for the scan line with a desired threshold for a PDP.

19. The system of claim 16, the AP determination component comprising a scan line determination component configured to:

determine contrasted color segment lengths of a second grid square along one or more scan lines that dissect the second grid square; and

compare the contrasted color segment lengths for the scan line with a desired threshold for an AP.

20. A computer readable storage medium comprising computer executable instructions that when executed via a processor on a computer perform a method for detecting a quick response (QR) code, comprising:

localizing an area of an image comprising a QR code by using a computer-based processor to combine pixel dynamic scale (DS), black-cell ratio (BR), and edge intensity sum (EIS) criteria determination to identify the QR code; and

detecting a pattern for the QR code comprising;

determining whether a position detection pattern (PDP) is located in respective areas of a first grid comprising the QR code; and

identifying an alignment pattern (AP), if present, comprising;

estimating an AP region using the PDPs; and

finding a center area of the AP by examining respective areas of a second grid comprising the estimated AP region.