A frequency domain technique for estimating rigid planar rotations

This work presents an original method for estimating planar rotations. The proposed technique operates in the frequency domain through the Fourier transform: hence, it uses all the information of the images and it can be efficiently implemented via FFT. The estimation of planar rotations lends itself to be treated in polar coordinates; however, the Cartesian to polar coordinates transformation turns out to be a delicate and heavy computational task. The proposed technique bypasses this problem by working in Cartesian coordinates directly and by exploiting the hermitian properties of the Fourier transform. Experimental evidence of the effectiveness and the robustness of the proposed method is reported.