3D modelling of archaeological small finds by the structure sensor range camera: comparison of different scanning applications

Today, range cameras represent a cheap, intuitive and effective technology for collecting the 3D geometry of objects and environments automatically and practically in real time. Such features can make these sensors a valuable tool for documenting archaeological small finds, especially when not expert users are involved. Therefore, in this work, Scanner and itSeez3D, two of the most promising scanning applications actually available for the Structure Sensor, a range camera specifically designed for mobile devices, were tested in order to evaluate their accuracy in modelling the 3D geometry of two archaeological artefacts, characterized by different shape and dimensions. The 3D models obtained through the two scanning applications were thus compared with the reference ones generated with the more accurate photogrammetric technique. The results demonstrate that both the applications show the same level of geometric accuracy, which amounts generally to very few millimetres, from an overall point of view, and, at the same time, they substantially point out the good quality of the Structure Sensor 3D reconstruction technology. In particular, the itSeez3D application is surely the best solution for the color restitution, even if it requires a payment of $7 to export and thus to use effectively each model generated. On the other side, Scanner is a free application and its geometric accuracy is comparable to that of itSeez3D, but, however, the colours are frequently smoothed and sometimes not fully rendered.