Estimation of affine transformations directly from tomographic projections

This paper presents a new approach to estimate affine transformations from tomographic projections. Instead of estimating the deformation from the reconstructed data, we introduce a method which works directly in the projection data. Using a parallel beam geometry, we show that any affine transformation results in scaling and translation of the projection data. Furthermore, we present a method which recovers the parameters of the deformation. Numerical experiments conclude the paper.