Image calibration

1. A method comprising:

receiving suspension level information of a suspension system of a vehicle, the suspension level information comprising an operating height of at least one wheel of the suspension system relative to a vehicle datum plane, the vehicle datum plane being a vehicle level when a plurality of cameras of the vehicle are at respective known positions and orientations relative to the ground, the vehicle datum plane having a fixed relationship with the position of the plurality of cameras;

determining a new vehicle plane based on the received suspension level information;

determining at least one camera pose parameter of the plurality of cameras mounted on the vehicle based on a difference between the new vehicle plane and the vehicle datum plane; and

calibrating an image captured from at least one of the plurality of cameras mounted on a vehicle using the at least one camera pose parameter.

2. The method as claimed in claim 1 , comprising

determining a suspension level difference between a current suspension level and a previous suspension level of the vehicle;

for at least one camera pose parameter, determining a camera pose parameter adjustment from the determined suspension level difference; and

determining an updated value of the at least one camera pose parameter by applying the determined camera pose parameter adjustment to a current value of the at least one camera pose parameter.

3. The method as claimed in claim 2 , wherein determining the updated value of the at least one camera pose parameter comprises:

reading the current value of the camera pose parameter;

forming an updated value of the at least one camera pose parameter by applying the determined camera pose parameter adjustment to the current value of the at least one camera pose parameter; and

storing the updated value of the at least one camera pose parameter as a new current value of the camera pose parameter.

4. The method as claimed in claim 1 , further comprising an initial step of determining a value of the at least one camera pose parameter when the camera is at the camera pose datum.

5. The method as claimed in claim 1 , wherein the vehicle datum plane is at a known height difference relative to a camera height parameter datum.

6. The method as claimed in claim 1 , wherein the value of the at least one camera pose parameter used to calibrate the image is the value of the at least one camera pose parameter associated with the suspension level at the time the image is captured.

7. The method as claimed in claim 1 , wherein calibrating the image from the camera comprises: projecting the image on a plane using the value of the at least one camera pose parameter determined using suspension level information from a suspension system of the vehicle.

8. The method as claimed in claim 1 , further comprising combining calibrated images with other image data using the value of the at least one camera pose parameter determined using suspension level information from the suspension system of the vehicle.

9. The method as claimed in claim 8 , wherein the other image data is graphical data.

10. The method as claimed in claim 8 , wherein the other image data is a calibrated image from another camera mounted on the vehicle.

11. The method as claimed in claim 1 , further comprising displaying images to a user.

12. An apparatus comprising:

a camera pose parameter function, coupled to receive suspension level information from a vehicle suspension system of a vehicle, the suspension level information comprising an operating height of at least one wheel of the suspension system relative to a vehicle datum plane, the vehicle datum plane being a vehicle level when a plurality of cameras of the vehicle are at respective known positions and orientations relative to the ground, the vehicle datum plane having a fixed relationship with the position of the plurality of cameras, the camera pose function further configured to determine a new vehicle plane based on the received suspension level information, and to determine a value of at least one camera pose parameter of the plurality of cameras based on a difference between the new vehicle plane and the vehicle datum plane; and

an image processor, coupled to receive the value of the at least one camera pose parameter from the camera pose parameter function, and operable to calibrate images captured from at least one of the plurality of cameras mounted to the vehicle using the value of the at least one camera pose parameter.