This paper describes a work in progress towards the implementation of a complete system that provides tourists with relevant visual information related to cultural heritage sites. Thanks to the diffusion of high-end mobile devices and the recent improvement in computer vision research on 3D Structure and Motion reconstruction, it is now possible to develop mobile mixed reality applications that can interact with spots of historical interest in the city. In particular we present an accurate localization of the mobile device that leverages on a pre-computed 3D structure to obtain image-model correspondences. Preliminary experiments with a calibrated camera – indoor and outdoor – demonstrate sufficient accuracy to support mixed reality.
