Two-Dimensional code generation method, two-dimensional code, two-dimensional code recognition method, and image recognition device

• US 8,050,502 B2
• Filed: 06/14/2007
• Issued: 11/01/2011
• Est. Priority Date: 06/21/2006
• Status: Active Grant

• Current Assignee: Bandai Company Limited
• Original Assignee: Namco Bandai Games Inc.
• Inventors: Sato, Kotaro
• Primary Examiner(s): KOZIOL, STEPHEN R
• Application Number:
  US11/812,067
• Publication Number:
  US 20070297679A1
• Time in Patent Office: 1,601 Days
• Field of Search: 382/181, 382/192
• US Class Current: 382/192
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06Q 20/347 Passive cards
• CPC Class Codes: G07F 7/08 by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• CPC Class Codes: G07F 7/125 Offline card verification

Abstract

A two-dimensional code in which given data is encoded as a two-dimensional image. The two-dimensional code includes as image elements: points each of which is placed at point placement reserved position in a two-dimensional region based on a binary data string uniquely associated with the given data according to a preset binary data string placement condition; and a line connecting each of the points and a connection target point according to a preset connection condition. The two-dimensional code is formed as a two-dimensional image by causing the line connecting the points to have a given width.

Claims

1. A two-dimensional code recognition method using a computer comprising:

a focused point pixel information detection step of detecting a reference point correspondence position of a recognition target image, calculating a focused point correspondence position on a recognition target image corresponding to a focused point set while being associated with a reference point based on the reference point correspondence position, detecting pixel information of the recognition target image based on the calculated focused point correspondence position, calculating a point placement reserved position on a recognition target image as the focused point correspondence position while using a point placement reserved position belonging to a main layer in a two-dimensional region as the focused point, and detecting the pixel information of the recognition target image based on the calculated point placement reserved position; and

a correspondence data calculation step of calculating correspondence data associated with a two-dimensional code based on the detected pixel information, determining a binary data string based on the detected pixel information, and calculating given data uniquely associated with the determined binary data string as the correspondence data,

wherein at least one of the steps is executed using a processor.

2. The two-dimensional code recognition method as defined in claim 1, further comprising:

a connection simulation step of performing a connection simulation process in which a point is placed at the point placement reserved position in the two-dimensional region based on the binary data string calculated in the correspondence data calculation step according to a preset binary data string placement condition, and the point and a connection target point are connected according to a preset connection condition; and

a line error detection/correction step of performing at least one of an error detection process and an error correction process by comparing a connection state of a sampled point detected from the recognition target image and a connection state of a sampled point obtained by the connection simulation process.

3. The two-dimensional code recognition method as defined in claim 1, further comprising:

a Fibonacci error detection/correction step of performing at least one of an error detection process and an error correction process for the binary data string calculated in the correspondence data calculation step based on a condition of the binary data string expressed by standard Fibonacci representation.

4. The two-dimensional code recognition method as defined in claim 1, further comprising:

a dummy point placement simulation step of performing a simulation process in which a dummy point is placed at a point placement reserved position belonging to a sublayer set in the two-dimensional region other than the main layer according to a preset dummy point placement condition; and

a dummy point error detection/correction step of performing at least one of an error detection process and an error correction process by comparing a position of a sampled dummy point detected from the recognition target image and a position of a dummy point obtained by the dummy point simulation process.

5. The two-dimensional code recognition method as defined in claim 1, further comprising:

a step of storing orientation determination information indicating relationship between a value of the binary data string and orientation of the recognition target image; and

an orientation determination step of determining the orientation of the recognition target image based on the binary data string calculated in the correspondence data calculation step and the orientation determination information.

6. The two-dimensional code recognition method as defined in claim 1, further comprising:

a recognition target image extraction step of extracting the recognition target image from input image data,

wherein the focused point pixel information detection step includes detecting the pixel information based on the recognition target image extracted in the recognition target image extraction step; and

wherein the recognition target image extraction step includes;

an outline extraction step of performing an outline extraction process in which an outline of a pixel group formed of continuous pixels having pixel information satisfying a predetermined pixel condition from the image data;

an outline determination step of determining whether or not a trace of the outline extracted in the outline extraction step satisfies a predetermined trace condition;

a pixel information change step of changing the pixel information of pixels forming the outline extracted in the outline extraction step to pixel information other than the pixel information satisfying the predetermined pixel condition when the predetermined trace condition is determined not to be satisfied in the outline determination step; and

an extraction step of extracting the image data corresponding to an inner region of the outline extracted in the outline extraction step as the recognition target image when the predetermined trace condition is determined to be satisfied in the outline determination step.

7. The two-dimensional code recognition method as defined in claim 6, further comprising:

a binarization step of subjecting image data to a binarization process,

wherein the outline extraction step includes extracting the outline from the image data subjected to the binarization process in the binarization step.

8. The two-dimensional code recognition method as defined in claim 7, further comprising:

a differentiation step of subjecting the image data to a differentiation process; and

a blur step of subjecting the image data subjected to the differentiation process in the differentiation process to a blur process in which the pixel information of the focused pixel and peripheral pixels placed around the focused pixel is averaged as new pixel information of the focused pixel,

wherein the binarization step includes subjecting the image data subjected to the blur process in the blur step to the binarization process.

9. The two-dimensional code recognition method as defined in claim 8, further comprising:

a line width detection step of detecting a width of a line forming the recognition target image extracted in the recognition target image extraction step,

wherein the blur step includes determining the number of times of the blur process based on the detected width and performing the blur process the determined number of times.

10. The two-dimensional code recognition method as defined in claim 7, further comprising:

a line width detection step of detecting a width of a line forming the recognition target image extracted in the recognition target image extraction step,

wherein the binarization step includes determining a threshold value used for the binarization process based on the detected width and performing the binarization process by using the determined threshold value.

11. An image recognition device recognizing a two-dimensional code, comprising:

a focused point pixel information detecting section, executed on a processor, which detects a reference point correspondence position of a recognition target image, calculates a focused point correspondence position on a recognition target image corresponding to a focused point set while being associated with a reference point based on the reference point correspondence position, detects pixel information of the recognition target image based on the calculated focused point correspondence position, calculates a point placement reserved position on a recognition target image as the focused point correspondence position while using a point placement reserved position belonging to a main layer in a two-dimensional region as the focused point, and detects the pixel information of the recognition target image based on the calculated point placement reserved position; and

a correspondence data calculating section which calculates correspondence data associated with a two-dimensional code based on the detected pixel information, determines a binary data string based on the detected pixel information, and calculates given data uniquely associated with the determined binary data string as the correspondence data.

12. The image recognition device as defined in claim 11, further comprising:

a connection simulation section which performs a connection simulation process in which a point is placed at the point placement reserved position in the two-dimensional region based on the binary data string calculated by the correspondence data calculating section according to a preset binary data string placement condition, and the point and a connection target point are connected according to a preset connection condition; and

a line error detection/correction section which performs at least one of an error detection process and an error correction process by comparing a connection state of a sampled point detected from the recognition target image and a connection state of a sampled point obtained by the connection simulation process.

13. The image recognition device as defined in claim 11, further comprising:

a Fibonacci error detection/correction section which performs at least one of an error detection process and an error correction process for the binary data string calculated in the correspondence data calculation step based on a condition of the binary data string expressed by standard Fibonacci representation.

14. The image recognition device as defined in claim 11, further comprising:

a dummy point placement simulation section which performs a simulation process in which a dummy point is placed at a point placement reserved position belonging to a sublayer set in the two-dimensional region other than the main layer according to a preset dummy point placement condition; and

a dummy point error detection/correction section which performs at least one of an error detection process and an error correction process by comparing a position of a sampled dummy point detected from the recognition target image and a position of a dummy point obtained by the dummy point simulation process.

15. The image recognition device as defined in claim 11, further comprising:

an orientation determination information storage section which stores orientation determination information that indicates a relationship between a value of the binary data string and an orientation of the recognition target image; and

an orientation determination section which determines the orientation of the recognition target image based on the binary data string calculated by the correspondence data calculation section and the orientation determination information stored in the orientation determination information storage section.

16. The image recognition device as defined in claim 11, further comprising:

a recognition target image extraction section which extracts the recognition target image from input image data,

wherein the focused point pixel information detection section detects the pixel information based on the recognition target image extracted by the recognition target image extraction section; and

wherein the recognition target image extraction section includes;

an outline extraction section which performs an outline extraction process in which an outline of a pixel group formed of continuous pixels having pixel information satisfying a predetermined pixel condition from the image data;

an outline determination section which determines whether or not a trace of the outline extracted by the outline extraction section satisfies a predetermined trace condition;

a pixel information change section which changes the pixel information of pixels forming the outline extracted by the outline extraction section to pixel information other than the pixel information satisfying the predetermined pixel condition when the predetermined trace condition is determined not to be satisfied by the outline determination section; and

an extraction section which extracts the image data corresponding to an inner region of the outline extracted by the outline extraction section as the recognition target image when the predetermined trace condition is determined to be satisfied by the outline determination section.

17. The image recognition device as defined in claim 16, further comprising:

a binarization section which subjects image data to a binarization process,

wherein the outline extraction process further includes extracting the outline from the image data subjected to the binarization process by the binarization section.

18. The image recognition device as defined in claim 17, further comprising:

a differentiation section which subjects the image data to a differentiation process; and

a blur section which subjects the image data subjected to the differentiation process by the differentiation section to a blur process in which the pixel information of the focused pixel and peripheral pixels placed around the focused pixel is averaged as new pixel information of the focused pixel,

wherein the binarization section subjects the image data subjected to the blur process by the blur section to the binarization process.

19. The image recognition device as defined in claim 18, further comprising:

a line width detection section which detects a width of a line forming the recognition target image extracted by the recognition target image extraction section,

wherein the blur section determines the number of times of the blur process based on the detected width and performs the blur process the determined number of times.

20. The image recognition device as defined in claim 17, further comprising:

a line width detection section detects a width of a line forming the recognition target image extracted by the recognition target image extraction section,

wherein the binarization section determines a threshold value used for the binarization process based on the detected width and performs the binarization process by using the determined threshold value.

21. A non-transitory computer-readable storage medium storing a program that causes a computer to execute a method comprising:

a focused point pixel information detection step of;

detecting a reference point correspondence position of a recognition target image,

calculating a focused point correspondence position on a recognition target image corresponding to a focused point set while being associated with a reference point based on the reference point correspondence position,

detecting pixel information of the recognition target image based on the calculated focused point correspondence position,

calculating a point placement reserved position on a recognition target image as the focused point correspondence position while using a point placement reserved position belonging to a main layer in a two-dimensional region as the focused point, and

detecting the pixel information of the recognition target image based on the calculated point placement reserved position; and

a correspondence data calculation step of;

calculating correspondence data associated with a two-dimensional code based on the detected pixel information,

determining a binary data string based on the detected pixel information, and

calculating given data uniquely associated with the determined binary data string as the correspondence data,

wherein at least on of the steps is executed using a processor.