Regularising limited view tomography using anatomical reference images and information theoretic similarity metrics

► The joint entropy prior applied to limited view transmission tomography is prone to local optima. ► We improved the JE prior's robustness to local optima by using a multiresolution optimisation scheme. ► An alternative solution was to approximate the joint pdf by a 2D Gaussian, yielding fast convergence and global convexity. ► The SG approximation was sensitive to outliers. We increased robustness by using an iterative reweighting scheme. ► To account for multiple clusters in the joint pdf, we modeled the joint pdf as the sum of several bivariate clusters.