Visually Compensating Eccentric In-plane Rotations for Image Stabilization on a Rotating Platform

摘要

For camera systems mounted on a rotating platform, it would be difficult to install the image sensor concentrically with the rotation axis. Free rotors are unmanned aerial vehicles that rotate about its centre of mass for flight. Small changes in mass distribution is sufficient to displace the free rotor’s rotation axis from the camera’s principal axis. This displacement can be modeled as a trochoid equation and the rotation centre of the trochoid for one arch recovered. The algorithm optimally compensates for the image eccentricity in three steps. Firstly, derotating the images about its principal axis. Secondly, computing the optimal values to translate the images in the image stream. Lastly, to shift the images using an affine transformation matrix. The results show that the algorithm is sufficiently accurate to compensate a time-varying rotation and time-varying translation image stream. It is also possible to visually observe the gyroscopic precession of the free rotor.