MATLAB: Is the calibration parameters differs when the distance between camera and check board pattern varies

Question

hi everyone, i have a camera set up with 5 camera's placed at 35 degrees apart around the boundary of a semicircle. On trying to calibrate, the parameters are varying whenever i change the position of the cameras i.e, moving all cameras with equal distance away from center of semicircle. Does the calibration of camera depend on depth? actually i have a set of image database taken from those cameras. But now the position of the cameras have changed in the camera set up.So if i calibrate now ,with the changed position of the cameras, will the calibration parameters be applicable to those images or not?

Answer 1

Hi Ram,

Could you please clarify which camera parameters you are talking about? Intrinsic camera parameters (optical center and the focal length) do not depend on camera's position. Neither do the distortion coefficient. On the other hand, camera extrinsics - rotation and translation relative to some world coordinate system - obviously do.

Also, keep in mind that while the actual camera intrinsics and distortion do not depend on camera's position, your estimate of them might. If you calibrate by taking images of a checkerboard 1 meter away vs. 5 meters away, you will get slightly different values.