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

• US 20070297679A1
• Filed: 06/14/2007
• Published: 12/27/2007
• Est. Priority Date: 06/21/2006
• Status: Active Grant

• Current Assignee: Bandai Company Limited (BANDAI NAMCO Holdings Inc.)
• Original Assignee: Namco Bandai Games Inc. (BANDAI NAMCO Holdings Inc.)
• Inventors: Sato, Kotaro
• Granted Patent: US 8,050,502 B2
• Time in Patent Office: Days
• 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 generation method comprising:

a binary data string generation step of generating a binary data string uniquely associated with given data based on the given data;

a point placement step of setting point placement reserved positions at each of which a point may be placed in a two-dimensional region, and placing a point at each of the point placement reserved positions in the two-dimensional region according to a preset binary data string placement condition based on the binary data string;

a connection step of connecting points placed in the two-dimensional region through a line according to a preset connection condition; and

an image generation step of generating an image of the two-dimensional code based on the line.

2. The two-dimensional code generation method as defined in claim 1,

wherein the point placement step includes setting a matrix based on the binary data string, associating the point placement reserved positions with elements of the matrix, and placing a point at each of the associated point placement reserved positions based on a value of each of the elements of the matrix.

3. The two-dimensional code generation method as defined in claim 1,

wherein the point placement step includes dividing the two-dimensional region into a plurality of cells arranged in a lattice, and using lattice points or representative points of the cells as the point placement reserved positions.

4. The two-dimensional code generation method as defined in claim 1,

wherein the connection step includes performing the connection process of connecting a given point and another point through a line when a necessary condition that a straight line connecting a given point and another point placed in the two-dimensional region does not cross a point placement reserved area is satisfied.

5. The two-dimensional code generation method as defined in claim 1,

wherein the point placement step includes setting a main layer in the two-dimensional region, and placing a point at part of the point placement reserved positions belonging to the main layer based on the binary data string.

6. The two-dimensional code generation method as defined in claim 5,

wherein, when a given one of the point placement reserved positions belongs to the main layer, the point placement step includes setting the main layer so that part of the point placement reserved positions located within a predetermined range around the given one of the point placement reserved positions does not belong to the main layer.

8. The two-dimensional code generation method as defined in claim 1,

wherein the point placement step includes setting a sublayer in the two-dimensional region other than the main layer, and placing a dummy point at part of the point placement reserved positions belonging to the sublayer according to a preset dummy point placement condition.

9. The two-dimensional code generation method as defined in claim 1,

wherein the point placement step includes setting a parity layer in the two-dimensional region other than the main layer, and placing a point at part of the point placement reserved positions belonging to the parity layer based on parity information.

10. The two-dimensional code generation method as defined in claim 9,

wherein the point placement step includes dividing the two-dimensional region into a plurality of areas, setting the parity information based on a point placed in an area other than a given area, and placing a point in part of the parity layer in the given area.

11. The two-dimensional code generation method as defined in claim 1,

wherein the binary data string generation step includes converting a given data into standard Fibonacci representation to generate the binary data string uniquely associated with the given data.

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

a reference position setting step of setting information indicating a reference position in the two dimension region,

wherein the image generation step includes generating a two-dimensional image including the information indicating the reference position.

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

an orientation information setting step of setting information indicating orientation of the two-dimensional region,

wherein the image generation step includes generating a two-dimensional image including the information indicating the orientation.

7. A two-dimensional code generation method comprising:

a binary data string generation step of generating a binary data string uniquely associated with given data based on the given data;

a point placement step of setting point placement reserved positions at each of which a point may be placed in a two-dimensional region, and placing a point at each of the point placement reserved positions in the two-dimensional region based on the binary data string; and

an image generation step of generating an image of the two-dimensional code based on the point,

the point placement step including setting a main layer in the two-dimensional region, placing a point at part of the point placement reserved positions belonging to the main layer based on the binary data string, and placing a dummy point at another part of the point placement reserved positions belonging to a layer in the two-dimensional region other than the main layer.

14. A two-dimensional code in which given data is encoded as a two-dimensional image, the two-dimensional code comprising 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 being formed as a two-dimensional image by causing the line connecting the points to have a given width.

15. The two-dimensional code as defined in claim 14,

wherein, when a necessary condition that a straight line connecting a first point and a second point among the points does not cross a point placement reserved area including the point placement reserved positions of the points other than the first and second points is satisfied, the second point is the connection target point, and the straight line is a line connecting the connection target point satisfying a predetermined condition and the first point.

16. The two-dimensional code as defined in claim 14,

wherein the points include a point placed at part of the point placement reserved positions belonging to a main layer set in the two-dimensional region based on the binary data string according to the preset binary data string placement condition.

18. The two-dimensional code as defined in claim 14,

wherein the points include a dummy point which is placed at part of the point placement reserved positions belonging to a sublayer set in the two-dimensional region other than the main layer according to a preset dummy point placement condition.

19. The two-dimensional code as defined in claim 14,

wherein the points include a point which is placed at part of the point placement reserved positions belonging to a parity layer set in the two-dimensional region other than the main layer based on parity information.

20. The two-dimensional code as defined in claim 14,

wherein the binary data string is generated based on standard Fibonacci representation of the given data.

17. A two-dimensional code in which given data is encoded as a two-dimensional image, the two-dimensional code comprising as image elements:

points placed at point placement reserved positions belonging to a main layer set in a two-dimensional region based on a binary data string uniquely associated with the given data; and

dummy points placed at point placement reserved positions belonging to a layer in the two-dimensional region other than the main layer,

the two-dimensional code being formed as a two-dimensional image by causing the points to have a given pattern.

21. A two-dimensional code recognition 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, and detecting pixel information of the recognition target image based on the calculated focused point correspondence position; and

a correspondence data calculation step of calculating correspondence data associated with a two-dimensional code based on the detected pixel information.

22. The two-dimensional code recognition method as defined in claim 21,

wherein the focused point pixel information detection step includes 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

wherein the correspondence data calculation step includes 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.

23. The two-dimensional code recognition method as defined in claim 22, 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.

24. The two-dimensional code recognition method as defined in claim 22, 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.

25. The two-dimensional code recognition method as defined in claim 22, 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.

26. The two-dimensional code recognition method as defined in claim 22, 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.

27. The two-dimensional code recognition method as defined in claim 22, 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.

28. The two-dimensional code recognition method as defined in claim 27, 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.

29. The two-dimensional code recognition method as defined in claim 28, 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.

30. The two-dimensional code recognition method as defined in claim 29, 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.

31. The two-dimensional code recognition method as defined in claim 28, 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.

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

a focused point pixel information detecting section 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, and detects pixel information of the recognition target image based on the calculated focused point correspondence position; and

a correspondence data calculating section which calculates correspondence data associated with a two-dimensional code based on the detected pixel information.