Position information detection device, position information detection method, and position information detection program

• US 8,441,440 B2
• Filed: 09/26/2006
• Issued: 05/14/2013
• Est. Priority Date: 09/27/2005
• Status: Expired due to Fees

• Current Assignee: Tamura Corporation
• Original Assignee: Tamura Corporation
• Inventors: Makita, Norikazu
• Primary Examiner(s): Bolotin, Dmitriy
• Application Number:
  US12/067,760
• Publication Number:
  US 20100253622A1
• Time in Patent Office: 2,422 Days
• Field of Search: 345157-167, 463/30, 463/32, 463/33, 463/2, 463/31, 463/37, 463/51
• US Class Current: 345/157
• CPC Class Codes: A63F 13/213 comprising photodetecting means, e.g. cameras, photodiodes or infrared cells A63F13/219, A63F13/655 take precedence
• CPC Class Codes: A63F 13/245 specially adapted to a particular type of game, e.g. steering wheels
• CPC Class Codes: A63F 13/40 Processing input control signals of video game devices, e.g. signals generated by the player or derived from the environment
• CPC Class Codes: A63F 13/5372 for tagging characters, objects or locations in the game scene, e.g. displaying a circle under the character controlled by the player
• CPC Class Codes: A63F 13/837 Shooting of targets
• CPC Class Codes: A63F 2300/1087 comprising photodetecting means, e.g. a camera
• CPC Class Codes: A63F 2300/8076 Shooting
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G03B 27/58 Baseboards, masking frames, or other holders for the sensitive material G03B27/53 takes precedence ; for electrophotographic copiers G03G15/65
• CPC Class Codes: G06F 3/0325 using a plurality of light emitters or reflectors or a plurality of detectors forming a reference frame from which to derive the orientation of the object, e.g. by triangulation or on the basis of reference deformation in the picked up image
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning

Abstract

A position information detection device, method, and program are provided, which are capable of detecting position information with high precision using simple and easily identified discrimination marks. A position information detection device has an image capture portion 203 which captures images of discrimination marks 102 arranged on a display 103, via a camera lens; a discrimination mark extraction portion 206 which extracts geometric figures from images captured by the image capture portion 203; a reference rectangle extraction portion 207 which extracts a reference rectangle image formed by connecting specific points in the geometric figures; a focal length calculation portion 213 which, based on a coordinate system specified by the reference rectangle image, calculates the focal length of the camera lens of the image capture portion 203 relative to the image display region of the display 103; and an indicated position calculation portion 210 which, based on the coordinate system and the focal length, calculates the indicated position of the image capture portion 203 relative to the image display region.

Claims

1. A position information detection device, comprising:

an image capture portion which captures images, by projecting onto an image capture element light-receiving face via a camera lens, of discrimination marks which contains multiple geometric graphics, creates a virtual reference rectangle with vertices of specific points of the multiple geometric graphics and with two diagonals of which lengths are equal, and is arranged on the side of an indication target plane;

a discrimination mark extraction portion which extracts geometric figures from images captured by said image capture portion at an attitude where lengths of two diagonals of a reference rectangle image projected by the image capture element light-receiving face are not equal;

a reference rectangle extraction portion which extracts the reference rectangle image with vertices of specific points in said geometric figures;

a focal length calculation portion which, based on a coordinate system specified by said reference rectangle image, calculates the focal length of the camera lens of said image capture portion with respect to said image capture element light-receiving face; and

an indicated position calculation portion which, based on said coordinate system and said focal length, calculates an indicated position of said image capture portion with respect to said indication target plane.

2. The position information detection device according to claim 1, comprising an image capture portion position calculation portion which, based on said coordinate system and said focal length, calculates the relative position of said image capture portion in a three-dimensional coordinate system set with said indication target plane as reference.

3. The position information detection device according to claim 1, comprising a rotation angle calculation portion which, based on said coordinate system before and after rotation of said image capture portion, calculates the rotation angle of said image capture portion.

4. The position information detection device according to claim 1, wherein that said specific points are the centroids of a plurality of geometric figures provided in said discrimination marks.

5. The position information detection device according to claim 1, wherein that said discrimination marks have a light source, enabling discrimination of said geometric figures from the image captured by said image capture portion.

6. The position information detection device according to claim 1, wherein that each geometric graphic of the reference rectangle is arranged so as to the vertical direction and other directions can be identified.

7. The position information detection device according to claim 1, wherein that said discrimination mark extraction portion extracts geometric figures by performing verification, in the vertical direction, of components which are continuous in the horizontal direction and of components which are not continuous.

8. A position information detection device, comprising:

an image capture portion which captures images, by projecting onto an image capture element light-receiving face via a camera lens, of discrimination marks arranged on the side of an indication target plane;

a discrimination mark extraction portion which extracts geometric figures from images captured by said image capture portion;

a reference rectangle extraction portion which extracts a reference rectangle image with vertices of specific points in said geometric figures;

a reference rectangle storage portion which stores the reference rectangle image extracted by said reference rectangle extraction portion;

a focal length calculation portion which, based on a coordinate system specified by said reference rectangle image, calculates the focal length of the camera lens of said image capture portion with respect to said image capture element light-receiving face;

an indicated position calculation portion which, based on said coordinate system and said focal length, calculates an indicated position of said image capture portion with respect to said indication target plane; and

a reference rectangle inference portion which, when discrimination marks cannot be extracted by said discrimination mark extraction portion, infers a reference rectangle image, by inferring the vertices of the discrimination marks which cannot be extracted, based on the reference rectangle image stored in said reference rectangle storage portion.

9. The position information detection device according to claim 8, wherein that said reference rectangle inference portion has:

a region calculation portion which calculates neighborhood regions of discrimination marks based on the immediately preceding extracted or inferred reference rectangle image stored in said reference rectangle storage portion;

a background light detection portion which detects background light to be blocked in said neighborhood regions;

a centroid inference portion which infers the centroid of discrimination marks in said neighborhood regions based on detection results by said background light detection portion; and

an inference portion which infers a reference rectangle image which includes the centroids as vertices based on the centroid inferred by said centroid inference portion.

10. The position information detection device according to claim 9, comprising a coordination portion which associates the centroid inferred by said centroid inference portion with the reference rectangle image stored in said reference rectangle storage portion, for use in inference by said inference portion.

11. The position information detection device according to claim 8, wherein that said image capture portion has a light-projection portion which irradiates said discrimination marks with light.

12. The position information detection device according to claim 8, wherein that said image capture portion, said discrimination mark extraction portion, said reference rectangle extraction portion, said reference rectangle storage portion, said focal length calculation portion, said indicated position calculation portion, and said reference rectangle inference portion are integrally formed.

13. The position information detection device according to claim 8, comprising an image capture portion position calculation portion which, based on said coordinate system and said focal length, calculates the relative position of said image capture portion in a three-dimensional coordinate system set with said indication target plane as reference.

14. The position information detection device according to claim 8, comprising a rotation angle calculation portion which, based on said coordinate system before and after rotation of said image capture portion, calculates the rotation angle of said image capture portion.

15. The position information detection device according to claim 8, wherein that said specific points are the centroids of a plurality of geometric figures provided in said discrimination marks.

16. The position information detection device according to claim 8, wherein that said discrimination marks have a light source, enabling discrimination of said geometric figures from the image captured by said image capture portion.

17. The position information detection device according to claim 8, wherein that said image capture portion has a light-projection portion which irradiates said discrimination marks with light.

18. A position information detection method, comprising the steps of:

capturing an image, by projecting onto an image capture element light-receiving face via a camera lens, of discrimination marks which contains multiple geometric graphics, creates a virtual reference rectangle with vertices of specific points of the multiple geometric graphics and with two diagonals of which lengths are equal, and is arranged on the side of an indication target plane by means of an image capture portion;

extracting geometric figures from the image captured by the image capture portion at an attitude where lengths of two diagonals of a reference rectangle image projected by the image capture element light-receiving face are not equal, by a discrimination mark extraction portion;

extracting a reference rectangle image with vertices of specific points in said geometric figures, by a reference rectangle extraction portion;

calculating the focal length of the camera lens of said image capture portion with respect to said image capture element light-receiving face, based on a coordinate system specified by said reference rectangle image, by a focal length calculation portion; and

calculating an indicated position of said image capture portion with respect to said indication target plane, based on said coordinate system and said focal length, by an indicated position calculation portion.

19. A position information detection method, comprising the steps of:

capturing an image, by projecting onto an image capture element light-receiving face via a camera lens, of discrimination marks arranged on the side of an indication target plane by an image capture portion;

extracting geometric figures from the image captured by the image capture portion, by a discrimination mark extraction portion;

extracting a reference rectangle image with vertices of specific points in said geometric figures, by a reference rectangle extraction portion;

storing the reference rectangle extracted by said reference rectangle extraction portion, by a reference rectangle storage portion;

calculating the focal length of the camera lens of said image capture portion with respect to said image capture element light-receiving face, based on a coordinate system specified by said reference rectangle image, by a focal length calculation portion;

calculating an indicated position of said image capture portion with respect to said indication target plane, based on said coordinate system and said focal length, by an indicated position calculation portion; and

inferring, by a reference rectangle inference portion, the reference rectangle image, by inferring the vertices of the discrimination marks which cannot be extracted, based on the immediately preceding extracted or inferred reference rectangle image stored in said reference rectangle storage portion when the discrimination mark extraction portion cannot extract discrimination marks.

20. A computer-readable non-transitory recording medium having stored therein a position information detection program, executable by a computer connected to an image capture portion, causing:

capture of an image, by projecting onto an image capture element light-receiving face via a camera lens, of discrimination marks which contains multiple geometric graphics, creates a virtual reference rectangle with vertices of specific points of the multiple geometric graphics and with two diagonals of which lengths are equal, and is arranged on the side of an indication target plane by means of the image capture portion;

extraction of geometric figures from the image captured by the image capture portion at an attitude where lengths of two diagonals of a reference rectangle image projected by the image capture element light-receiving face are not equal;

extraction of a reference rectangle image with vertices of specific points in said geometric figures;

calculation of the focal length of the camera lens of said image capture portion with respect to said image capture element light-receiving face, based on a coordinate system specified by said reference rectangle image; and

calculation of an indicated position of said image capture portion with respect to said indication target plane, based on said coordinate system and said focal length.

21. A computer-readable non-transitory recording medium having stored therein a position information detection program, executable by a computer connected to an image capture portion, causing:

capture of an image, by projecting onto an image capture element light-receiving face via a camera lens, of discrimination marks arranged on the side of an indication target plane by the image capture portion;

extraction of geometric figures from the image captured by the image capture portion;

extraction of a reference rectangle image with vertices of specific points in said geometric figures;

storage of said reference rectangle image;

calculation of the focal length of the camera lens of said image capture portion with respect to said image capture element light-receiving face, based on a coordinate system specified by said reference rectangle image;

calculation of an indicated position of said image capture portion with respect to said indication target plane, based on said coordinate system and said focal length; and

inference of the reference rectangle image, by inferring the vertices of the discrimination marks which cannot be extracted, based on the immediately preceding extracted or inferred stored reference rectangle image when discrimination marks cannot be extracted.