Orientation device method for coordinate generation employed thereby

• US 20080113799A1
• Filed: 01/11/2008
• Published: 05/15/2008
• Est. Priority Date: 05/10/2005
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Chao, Tzu-Yi, Chen, Hsin-Chia, Lin, Chih-Hsin
• Granted Patent: US 7,611,412 B2
• Time in Patent Office: Days
• US Class Current: 463/37
• 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 13/219 for aiming at specific areas on the display, e.g. light-guns
• CPC Class Codes: A63F 13/426 involving on-screen location information, e.g. screen coordinates of an area at which the player is aiming with a light gun
• CPC Class Codes: A63F 13/5375 for graphically or textually suggesting an action, e.g. by displaying an arrow indicating a turn in a driving game
• CPC Class Codes: A63F 13/837 Shooting of targets
• CPC Class Codes: A63F 2300/1062 being specially adapted to a type of game, e.g. steering wheel
• CPC Class Codes: A63F 2300/305 for providing a graphical or textual hint to the player
• CPC Class Codes: A63F 2300/8076 Shooting

Abstract

A method for coordinate generation to be implemented using an orientation device includes the steps of: providing at least three reference marks on a target; aiming the orientation device at a target point on the target, and operating the orientation device such that the orientation device is able to capture an image of the target that contains the reference marks; assigning absolute coordinates to the reference marks in the image captured by the orientation device; and determining relative coordinates of the target point in a coordinate space of the target with reference to the absolute coordinates assigned to the reference marks. An orientation device that performs the method is also disclosed.

Claims

1. A method for coordinate generation to be implemented using an orientation device that is provided with a sensor, said method comprising the steps of:

A) providing at least three reference marks on a target;

B) aiming the orientation device at a target point on the target, and operating the orientation device such that the sensor is able to capture an image of the target that contains the reference marks;

C) assigning absolute coordinates to the reference marks in the image captured in step B); and

D) determining relative coordinates of the target point in a coordinate space of the target with reference to the absolute coordinates of the reference marks assigned in step C).

2. The method as claimed in claim 1, wherein step C) includes the sub-steps of:

C1) computing coordinates of the reference marks in the image captured in step B) to obtain vector combinations; and

C2) computing the vector combinations to obtain the absolute coordinates of the reference marks projected onto the coordinate space of the target.

3. The method as claimed in claim 2, wherein step C2) includes the sub-steps of:

C2-1) finding a pair of most parallel vectors from the vector combinations;

C2-2) forming a first mark group from one of the vectors found in sub-step C2-1), and a second mark group from the other of the vectors found in sub-step C2-1);

C2-3) finding a pair of the vectors, a vertex of which is found in the second mark group, and endpoints of which are found in the first mark group;

C2-4) obtaining the absolute coordinates of the endpoints in the first mark group based on a vector product of the vectors found in sub-step C2-3);

C2-5) determining a pair of the vectors, a vertex of which is found in the first mark group, and endpoints of which are found in the second mark group; and

C2-6) obtaining the absolute coordinates of the endpoints in the second mark group based on a vector product of the vectors found in sub-step C2-5).

4. The method as claimed in claim 1, further comprising the steps of:

E) aiming the orientation device at an arbitrary point on the target; and

F) operating the orientation device such that the sensor is able to capture an image of the target that contains the reference marks;

wherein step D) includes the sub-steps of;

D1) determining coordinates of the reference marks from the image captured in step F);

D2) performing projective transformation calculations upon the coordinates of the reference marks determined in sub-step D1) to obtain a transformation matrix;

D3) correcting an image-capturing axis of the sensor of the orientation device with reference to the transformation matrix obtained in sub-step D2) and an established coordinate space relation between the target and the orientation device; and

D4) determining the relative coordinates of the target point with reference to the corrected image-capturing axis.

5. The method as claimed in claim 4, further comprising the steps of:

G) aiming the orientation device at one of the reference marks;

H) operating the orientation device such that the sensor is able to capture an image of the target that contains the reference mark aimed in step G);

I) determining the coordinates of the reference mark aimed in step G) from the image captured in step H); and

J) correlating a coordinate space of the orientation device with a coordinate space of the target to thereby establish the coordinate space relation.

6. The method as claimed in claim 1, wherein step D) includes the sub-steps of:

D1) performing projective transformation calculations upon the absolute coordinates of the reference marks assigned in step C) to obtain a transformation matrix;

D2) correcting an image-capturing axis of the sensor of the orientation device with reference to the transformation matrix obtained in sub-step D1); and

D3) determining the relative coordinates of the target point with reference to the corrected image-capturing axis.

7. The method as claimed in claim 1, further comprising the step of:

E) aiming the orientation device at one corner of the target, and operating the orientation device such that the sensor is able to capture an image of the target that contains the reference marks;

wherein step D) includes the sub-steps of;

D1) determining coordinates of the reference marks from the image captured in step E);

D2) performing projective transformation calculations upon the coordinates of the reference marks determined in sub-step D1) to obtain a transformation matrix;

D3) correcting an image-capturing axis of the sensor of the orientation device with reference to the transformation matrix obtained in sub-step D2); and

D4) determining the relative coordinates of the target point with reference to the corrected image-capturing axis.

8. A system, comprising:

a target defining a coordinate space;

at least three reference marks provided on said target; and

an orientation device defining a coordinate space correlated with the coordinate space of said target, and including

a sensor that is able to capture an image of said target that contains said reference marks when said orientation device is operated while aiming at a target point on said target, and

a processor that is coupled to said sensor, and that is operable so as to compute absolute coordinates of said reference marks in the image captured by said sensor and so as to determine relative coordinates of the target point in the coordinate space of said target with reference to the absolute coordinates of said reference marks.

9. The system as claimed in claim 8, wherein said processor obtains vector combinations from coordinates of said reference marks computed thereby, and the absolute coordinates of said reference marks from the vector combinations obtained thereby.

10. The system as claimed in claim 8, wherein said processor performs projective transformation calculations upon the absolute coordinates of said reference marks to obtain a transformation matrix, and determines the relative coordinates of the target point in the coordinate space of said target with reference to the transformation matrix obtained thereby.

11. The system as claimed in claim 8, wherein each of said reference marks is a light source.

12. The system as claimed in claim 11, wherein said light source is a light-emitting diode.

13. The system as claimed in claim 8, wherein each of said reference marks is a reflector.

14. The system as claimed in claim 8, wherein each of said reference marks is a colored pattern.

15. The system as claimed in claim 8, wherein said target is a screen of a display.

16. The system as claimed in claim 15, wherein said display is one of a liquid crystal display, a plasma display panel, a cathode-ray tube, and a projector display.

17. The system as claimed in claim 8, wherein said orientation device is a light gun.

18. The system as claimed in claim 8, wherein said sensor is one of a complementary metal-oxide-semiconductor (CMOS) device and a charged-coupled device (CCD).

19. The system as claimed in claim 8, further comprising a communications interface coupled to said processor and adapted to provide the relative coordinates of the target point to a game controller.

20. An orientation device for a system that includes a target provided with at least three reference marks, said orientation device defining a coordinate space correlated with a coordinate space of the target, and comprising:

a sensor adapted to capture an image of the target that contains the reference marks when said orientation device is operated while aiming at a target point on the target; and

a processor coupled to said sensor, and operable so as to compute absolute coordinates of the reference marks in the image captured by said sensor and so as to determine relative coordinates of the target point in the coordinate space of the target with reference to the absolute coordinates of the reference marks.

21. The orientation device as claimed in claim 20, wherein said processor obtains vector combinations from coordinates of said reference marks computed thereby, and the absolute coordinates of said reference marks from the vector combinations obtained thereby.

22. The orientation device as claimed in claim 20, wherein said processor performs projective transformation calculations upon the absolute coordinates of said reference marks to obtain a transformation matrix, and determines the relative coordinates of the target point in the coordinate space of said target with reference to the transformation matrix obtained thereby.

23. The orientation device as claimed in claim 20, further comprising a communications interface coupled to said processor and adapted to provide the relative coordinates of the target point to a game controller.

24. The orientation device as claimed in claim 23, wherein said communications interface is one of a serial communications interface and a parallel communications interface.