Systems and methods for on-line marker-less camera calibration using a position tracking system

1. A system facilitating on-line calibration of an imaging camera, said system comprising:

a first sensor positioned with respect to an imager;

a second sensor positioned with respect to a camera source; and

a transmitter positioned with respect to an object to be imaged that transmits tracking data to said first and second sensors during said on-line calibration,

wherein a first off-line calibration characterizes a transformation from a coordinate system of said imager to a coordinate system of said first sensor positioned with respect to said imager and a second off-line calibration characterizes a transformation from a coordinate system of said camera source to a coordinate system of said second sensor positioned with respect to said camera source, and

wherein intrinsic parameters of said camera source are quantified by a transformation from the coordinate system of said imager to the coordinate system of said camera source based on said first and second off-line calibrations and said tracking data.

2. The system of claim 1 , wherein said first and second sensors and said transmitter comprise electromagnetic first and second sensors and transmitter.

3. The system of claim 1 , wherein said intrinsic parameters of said camera source are quantified by a transformation Imager T Cam = Imager T Rx2 · Rx2 T Tx · Tx T Rx1 · Rx1 T Cam , wherein Imager T Rx2 is a coordinate system transformation from the coordinate system of said imager to the coordinate system of said first sensor, Rx1 T Cam is a coordinate system transformation from the coordinate system of said camera source to the coordinate system of said second sensor, and RX2 T Tx and Tx T Rx1 are dynamic coordinate system transformations provided by tracking information from said first and second sensors and said transmitter.

4. The system of claim 1 , wherein at least one of said imager and said camera source are mounted on a support member.

5. The system of claim 4 , wherein said support member comprises at least one of a C-arm, an L-arm and an O-arm.

6. The system of claim 4 , wherein said first and second sensors and said transmitter dynamically track deflection of said support member.

7. The system of claim 1 , wherein said first and second sensors and said transmitter obtain at least one of position and orientation data for said object.

8. The system of claim 1 , wherein said first and second off-line calibrations are performed at a single arbitrary camera position.

9. The system of claim 1 , wherein said on-line calibration is performed without using markers.

10. A method for calibration of an imaging system, said method comprising:

characterizing a transformation from a coordinate system of an imager to a coordinate system of a first sensor positioned with respect to said imager using a first off-line calibration;

characterizing a transformation from a coordinate system of an imaging camera source to a coordinate system of a second sensor positioned with respect to said imaging camera source using a second off-line calibration; and

quantifying intrinsic parameters of said imaging camera source based on a transformation from the coordinate system of said imager to the coordinate system of said imaging camera source based on said first and second off-line calibrations and tracking data transmitted from a transmitter positioned with respect to an object being imaged to said first and second sensors during an on-line calibration.

11. The method of claim 10 , wherein said quantifying step further comprises quantifying intrinsic parameters of said imaging camera source based a transformation Imager T Cam = Imager T Rx2 · Rx2 T Tx · Tx T Rx1 · Rx1 T Cam , wherein Imager T Rx2 is a coordinate system transformation from the coordinate system of said imager to the coordinate system of said first sensor, Rx1 T Cam is a coordinate system transformation from the coordinate system of said imaging camera source to the coordinate system of said second sensor, and Rx2 T TX and Tx T Rx1 are dynamic coordinate system transformations provided by tracking information from said first and second sensors and said transmitter.

12. The method of claim 10 , wherein at least one of said imager and said imaging camera source are mounted on a support member.

13. The method of claim 12 , wherein said first and second sensors and said transmitter dynamically track deflection of said support member.

14. The system of claim 10 , wherein said first and second sensors and said transmitter obtain tracking data related to said object.

15. The method of claim 10 , wherein said first and second off-line calibrations are performed at a single arbitrary camera position.

16. The method of claim 10 , further comprising modeling said imaging camera source based on said intrinsic parameters.

17. The method of claim 10 , wherein said on-line calibration is performed without using markers.

18. A non-transitory computer-readable medium having a set of instructions for execution on a computer, said set of instructions comprising:

a first transformation routine characterizing a transformation from a coordinate system of an imager to a coordinate system of a first sensor positioned with respect to said imager using a first off-line calibration;

a second transformation routine characterizing a transformation from a coordinate system of an imaging camera source to a coordinate system of a second sensor positioned with respect to said imaging camera source using a second off-line calibration; and

a camera characterization routine quantifying intrinsic parameters of said imaging camera source based on a transformation from the coordinate system of said imager to the coordinate system of said imaging camera source based on said first and second off-line calibrations and tracking data transmitted from a transmitter positioned with respect to an object being imaged to said first and second sensors during an on-line calibration.

19. The set of instructions of claim 18 , wherein said camera characterization routine quantifies intrinsic parameters of said imaging camera source based a transformation Imager T Cam = Imager T Rx2 · Rx2 T Tx · Tx T Rx1 · Rx1 T Cam , wherein Imager T Rx2 is a coordinate system transformation from the coordinate system of said imager to the coordinate system of said first sensor, Rx1 T Cam is a coordinate system transformation from the coordinate system of said imaging camera source to the coordinate system of said second sensor, and Rx2 T Tx and Tx T Rx1 are dynamic coordinate system transformations provided by tracking information from said first and second sensors and said transmitter.

20. The set of instructions of claim 18 , wherein said first and second off-line calibrations are performed at a single arbitrary camera position.

21. The set of instructions of claim 18 , further comprising a modeling routine for modeling said imaging camera source based on said intrinsic parameters.

22. The set of instructions of claim 18 , further comprising a tracking routine using said first and second sensors and said transmitter to dynamically track deflection of a support member upon which at least one of said imager and said imaging camera source are mounted.

23. The set of instructions of claim 18 , wherein said on-line calibration is performed without using markers.