2D/3D registration of micro-CT data to multi-view photographs based on a 3D distance map

In this work we present a method for registration of a CT-derived mouse skin surface to two or more 2D, geometrically calibrated, photographs of the same animal using a similarity transformation model. We show that by using a 3D distance map, which is reconstructed from the animal skin silhouettes in the 2D photographs, and by penalizing large angle differences between distance map gradients and CT-based skin surface normals, we are able to construct a registration criterion that is robust to silhouette outliers and yields accurate results for synthetic and real data (mean skin surface distance 0.12 mm and 1.35 mm respectively).