Vehicle vision system with camera calibration

1. A camera calibration system for a vehicle, said camera calibration system comprising:

at least one camera disposed at a vehicle and having a field of view exterior of the vehicle;

an image processor operable to process frames of image data captured by said at least one camera;

wherein, during a second ignition cycle of the vehicle that is subsequent to a first ignition cycle of the vehicle, said camera calibration system compares a frame of image data captured by said at least one camera during the first ignition cycle to a frame of image data captured by said at least one camera at the onset of the second ignition cycle;

wherein said camera calibration system, via comparison of the frames of image data captured by said at least one camera, determines a change in orientation of said at least one camera from a previous orientation during the first ignition cycle of the vehicle to a current orientation at the onset of the second ignition cycle of the vehicle.

2. The camera calibration system of claim 1 , wherein said camera calibration system stores the frame of image data captured by said at least one camera at or near an end of the first ignition cycle of the vehicle, and wherein, at the onset of the second ignition cycle of the vehicle, said camera calibration compares the frame of image data captured by said at least one camera at the onset of the second ignition cycle to the stored frame of captured image data to determine a change in orientation of said at least one camera.

3. The camera calibration system of claim 2 , wherein said camera calibration system compares detected features of the frame of image data captured by said at least one camera during the second ignition cycle to detected features of the stored frame of captured image data to determine the change in orientation of said at least one camera.

4. The camera calibration system of claim 2 , wherein said camera calibration system stores the frame of image data captured by said at least one camera when the vehicle is stationary at or near the end of the first ignition cycle of the vehicle.

5. The camera calibration system of claim 2 , wherein said camera calibration system stores the frame of image data captured by said at least one camera when the vehicle is stationary at or near the start of the second ignition cycle of the vehicle.

6. The camera calibration system of claim 1 , wherein said camera calibration system determines a change in orientation of said at least one camera that is indicative of loading or unloading of the vehicle between the first and second ignition cycles.

7. The camera calibration system of claim 1 , comprising a display operable to display video images derived from image data captured by said at least one camera.

8. The camera calibration system of claim 7 , wherein, responsive to determination of a change in orientation of said at least one camera, said camera calibration system adjusts processing of captured image data to accommodate the determined change in orientation.

9. The camera calibration system of claim 1 , wherein said at least one camera comprises a rear camera disposed at a rear portion of the vehicle and having a field of view rearward of the vehicle.

10. The camera calibration system of claim 1 , wherein said at least one camera comprises a plurality of cameras disposed at the vehicle and having respective fields of view exterior of the vehicle.

11. A camera calibration system for a vehicle, said camera calibration system comprising:

at least one camera disposed at a vehicle and having a field of view exterior of the vehicle;

an image processor operable to process image data captured by said at least one camera;

wherein said image processor is operable, via processing of image data captured by said at least one camera, to determine a change in orientation of said at least one camera;

wherein said camera calibration system stores image data captured by said at least one camera when the vehicle is stationary at or near the end of a previous ignition cycle of the vehicle;

wherein said at least one camera captures image data when the vehicle is stationary at an onset of a current ignition cycle of the vehicle that is subsequent to the previous ignition cycle; and

wherein said camera calibration system compares detected features of the image data captured by said at least one camera at the onset of the current ignition cycle to detected features of the stored image data captured by said at least one camera at or near the end of the previous ignition cycle to determine the change in orientation of said at least one camera.

12. The camera calibration system of claim 11 , wherein said camera calibration system determines a change in orientation of said at least one camera that is indicative of loading or unloading of the vehicle between the previous and current ignition cycles.

13. The camera calibration system of claim 11 , comprising a display operable to display video images derived from image data captured by said at least one camera.

14. The camera calibration system of claim 13 , wherein, responsive to determination of a change in orientation of said at least one camera, said camera calibration system adjusts processing of captured image data to accommodate the determined change in orientation.

15. The camera calibration system of claim 11 , wherein said at least one camera comprises a rear camera disposed at a rear portion of the vehicle and having a field of view rearward of the vehicle.

16. The camera calibration system of claim 11 , wherein said at least one camera comprises a plurality of cameras disposed at the vehicle and having respective fields of view exterior of the vehicle.

17. A camera calibration system for a vehicle, said camera calibration system comprising:

at least one camera disposed at a vehicle and having a field of view exterior of the vehicle;

an image processor operable to process frames of image data captured by said at least one camera;

a display operable to display video images derived from image data captured by said at least one camera;

wherein, during a second ignition cycle of the vehicle that is subsequent to a first ignition cycle of the vehicle, said camera calibration system compares a first frame of image data captured by said at least one camera during the first ignition cycle to a second frame of image data captured by said at least one camera at the onset of the second ignition cycle;

wherein said camera calibration system, via comparison of the frame of image data captured by said at least one camera during the first ignition cycle to the frame of image data captured by said at least one camera at the onset of the second ignition cycle, determines a change in orientation of said at least one camera from a previous orientation during the first ignition cycle of the vehicle to a current orientation at the onset of the second ignition cycle of the vehicle;

wherein said camera calibration system determines a change in orientation of said at least one camera that is indicative of loading or unloading of the vehicle between the previous and current ignition cycles; and

wherein, responsive to determination of a change in orientation of said at least one camera, said camera calibration system adjusts processing of captured image data to accommodate the determined change in orientation.

18. The camera calibration system of claim 17 , wherein said camera calibration stores at least one frame of image data captured by said at least one camera at or near an end of the first ignition cycle of the vehicle, and wherein, at the onset of the second ignition cycle of the vehicle, said camera calibration system compares the frame of image data captured by said at least one camera during the second ignition cycle to the stored at least one frame of captured image data to determine the change in orientation of said at least one camera, and wherein said camera calibration system compares detected features of the frame of image data captured by said at least one camera during the second ignition cycle to detected features of the stored at least one frame of captured image data to determine the change in orientation of said at least one camera.

19. The camera calibration system of claim 17 , wherein said at least one camera comprises a rear camera disposed at a rear portion of the vehicle and having a field of view rearward of the vehicle.

20. The camera calibration system of claim 17 , wherein said at least one camera comprises a plurality of cameras disposed at the vehicle and having respective fields of view exterior of the vehicle.