METHOD FOR COMPENSATING HARDWARE MISALIGNMENTS IN A CAMERA

• US 20080204560A1
• Filed: 02/12/2008
• Published: 08/28/2008
• Est. Priority Date: 02/19/2007
• Status: Active Grant

• Current Assignee: Axis AB (Canon Inc.)
• Original Assignee: Axis AB (Canon Inc.)
• Inventors: Nilsson, Martin
• Granted Patent: US 8,405,731 B2
• Time in Patent Office: Days
• US Class Current: 348/187
• CPC Class Codes: H04N 17/002 for television cameras
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"
• CPC Class Codes: H04N 7/185 from a mobile camera, e.g. for remote control

Abstract

A method for compensating hardware misalignments in a camera is presented. The camera includes a maneuverable part and a fixed part, and the maneuverable part is controlled by a steering motor system. In a first step of the method mechanical coordinates from the steering motor system is received, wherein the mechanical coordinates correspond to a pan and tilt position, the pan and tilt position having a complementary pan and tilt position. Next, pre-determined calibration data corresponding to the received mechanical coordinates is read from a memory wherein the pre-determined calibration data describes a relationship between a pan and tilt position and a complementry pan and tilt position, and then compensated coordinates are determined based upon the received mechanical coordinates and the pre-determined calibration data.

Claims

1. A method for compensating hardware misalignments in a camera comprising a maneuverable part and a fixed part, wherein said maneuverable part is controlled by a steering motor system, said method comprising

receiving mechanical coordinates from said steering motor system, wherein said mechanical coordinates correspond to a pan and tilt position, said pan and tilt position having a complementary pan and tilt position,

reading pre-determined calibration data corresponding to said received mechanical coordinates from a memory comprised in said camera, wherein said pre-determined calibration data describes a relationship between said pan and tilt position and said complementry pan and tilt position, and

determining compensated coordinates based upon said received mechanical coordinates and said pre-determined calibration data.

2. The method according to claim 1, wherein said maneuverable part comprises a zooming optical system, said method further comprises

receiving at least one zoom position of said zooming optical system,

reading pre-determined calibration data corresponding to said at least one zoom position from said memory, and

determining compensated coordinates based upon said received at least one zoom position and said pre-determined calibration data.

3. The method according to claim 1, wherein said method further comprises

transmitting said compensated coordinates from said camera to a user interface apparatus, and

presenting said compensated coordinates on said user interface apparatus.

4. The method according to claim 1, wherein said method further comprises

transmitting image data to an image handling device,

transmitting said compensated coordinates to said image data handling device, and

processing said image data and said compensated coordinates in said image data handling device.

5. The method according to claim 1, wherein said method further comprises

receiving camera target coordinates,

reading pre-determined calibration data corresponding to said received camera target coordinates from said memory comprised in said camera,

determining camera target mechanical coordinates based upon said received camera target coordinates and said pre-determined calibration data, and

moving said maneuverable part of said camera in accordance to said determined camera target mechanical coordinates.

6. The method according to claim 1, wherein a pan range of said maneuverable part is equal or greater than 180°

thereby enabling said maneuverable part to reach at least one view by using a plurality of different mechanical coordinates, wherein said pre-determined calibration data comprises a combination of a set of said plurality of different mechanical coordinates.

7. The method according to claim 6, wherein said plurality of different mechanical coordinates comprises a set of upright mechanical coordinates and a set of flipped mechanical coordinates.

8. The method according to claim 6, wherein said pre-determined calibration data comprises at least one difference value determined by subtracting one of said different mechanical coordinates by a theoretic value.

9. The method according to claim 6, wherein said pre-determined calibration data comprises an intermediate position of said set of said plurality of different mechanical coordinates.

10. The method according to claim 1, wherein said hardware misalignments are caused by rotation around at least one axis in the group of a pan axis and a tilt axis.

22. A computer program product comprising software instructions arranged to perform the method according to claim 1, when downloaded and run in an apparatus.

11. A camera comprising

a maneuverable part comprising an optical system,

a fixed part,

a steering motor system arranged to control said maneuverable part,

a memory arranged to hold pre-determined calibration data,

a processor configured to receive mechanical coordinates from said steering motor system, wherein said mechanical coordinates correspond to a pan and tilt position, said pan and tilt position having a complementary pan and tilt position, to read pre-determined calibration data from said memory, wherein said pre-determined calibration data corresponds to said mechanical coordinates and wherein said pre-determined calibration data describes a relationship between said pan and tilt position and said complementry pan and tilt position, to determine compensated coordinates based upon said mechanical coordinates and said pre-determined calibration data.

12. The camera according to claim 11, wherein said optical system of said maneuverable part comprises a zooming optical system, and said processor is further configured to receive at least one zoom position from said zooming optical system, and to determine compensated coordinates based upon said at least one received zoom position and said pre-determined calibration data.

13. The camera according to claim 11, further comprising

a transmitter adapted to transmit said compensated coordinates from said camera to a user interface apparatus.

14. The camera according to claim 13, wherein said transmitter is further adapted to transmit image data and said compensated coordinates to an image handling device.

15. The camera according to claim 11, wherein said processor is further configured to receive camera target coordinates, to read pre-determined calibration data corresponding to said received camera target coordinates from said memory comprised in said camera, and to determine camera target mechanical coordinates based upon said received camera target coordinates and said pre-determined calibration data, and wherein said steering motor system is configured to move said maneuverable part of said camera in accordance to said determined camera target mechanical coordinates.

16. The camera according to claim 11, wherein a pan range of said maneuverable part is equal to or greater than 180°

thereby enabling said maneuverable part to reach at least one field of view by using a plurality of different mechanical coordinates, wherein said pre-determined calibration data comprises a combination of a set of said plurality of different mechanical coordinates.

17. The camera according to claim 16, wherein a tilt range of said maneuverable part of said camera includes said pan axis.

18. The camera according to claim 16, wherein said plurality of different mechanical coordinates comprises a set of upright mechanical coordinates and a set of flipped mechanical coordinates.

19. The camera according to claim 16, wherein said pre-determined calibration data comprises at least one difference value determined by subtracting one of said different mechanical coordinates by a theoretic value.

20. The camera according to claim 16, wherein said pre-determined calibration data comprises an intermediate position of said set of said plurality of different mechanical coordinates.

21. A system comprising

a data network,

a user interface apparatus connected to said data network, and

at least one camera according to claim 11.