A Shadow Based Method for Image to Model Registration

This paper presents a novel method for 2D to 3D texture mapping using shadows as cues. This work is part of a larger set of methods that address the entire 3D modeling pipeline to create geometrically and photometrically accurate models using a variety of data sources. The focus is on building models of large outdoor, urban, historic and archaeological sites. We pose registration of 2D images with the 3D model as an optimization problem that uses knowledge of the Sun´s position to estimate shadows in a scene, and use the shadows produced as a cue to refine the registration parameters. Results are presented for registration where ground truth is known and also for a large scale model consisting of 14 3D scans and 10 images on a large archaeological site in Sicily.