From perspective restitution to mixed reality : reconstruction of San Nicolò dei Carmelitani church in Palermo

Digital surveying and representation tools are widely used for the virtual reconstruction of historic buildings that have vanished or have been transformed. When changes or destructions occurred after the first half of the XIX century, the reconstruction process can be based on photographic images, if available. Photos provide an effective support for the reconstruction of lost buildings, especially when drawings or previous surveys are not available. The 3D reconstruction from archive images has become a relevant topic in almost recent years. In 2013 Migliari et al. proposed a method that allows the reconstruction of 3D models from a single image using perspective restitution. In those years computer engineers developed digital tools that supported inner and outer orientation of archive images. In the years from 2017 to 2019 several studies focused on the reconstruction of lost buildings with photogrammetric traditional and SfM techniques. In this study an un-assisted process is proposed for the reconstruction of a lost buildings from a single image: perspective restitution developed with digital representation tools allowed the retrieval of inner and outer orientation of archive photos and the reconstruction of the case study, a church that no longer exist. Outer orientation and scaling were provided by the lidar survey of those buildings that are still in place. Finally, a motion tracking commercial software has been tested for the contextualization of the 3D reconstruction model.