Urban models texturing from un-calibrated photographs

We present a system to automatically fit a CAD urban model to a structure from motion sparse reconstruction. Fitting the model to the sparse reconstruction is defined and solved as an absolute orientation problem. The novelty of our approach is the use of facade correspondences to compute the absolute orientation. We also propose a solution to automatically establish facade correspondences using a pseudo-RANSAC procedure. Our system consists of four parts: a robust structure from motion recovery framework able to register accurately a set of digital photographs, a method to recover the principal walls of a scene from a 3d sparse reconstruction using a robust RANSAC scheme, a method to fit automatically a 3d model to a set of 3d wall planes, and finally, a user interface allowing scene visualisation and photorealistic rendering of urban 3d models from a set of calibrated photographs.