Photogrammetric approaches for the virtual reconstruction of damaged historical remains

The photogrammetrical techniques are, in this moment, experimenting new approaches based on innovative algorithms. The recent availability of high resolution cameras and sensors made possible the fast and accurate acquisition of complex geometries. On the other hand, manage such amount of data need for optimized procedure to automatize the geometric extraction of the geometric features. In this paper different photogrammetric techniques will be compared with direct measurement of the same site with laser scanner. The test site is the main door of the palace of the ex seminar archbishop’s palace of Taranto town, whose construction goes up again to the XVII century, was surveyed. The survey has been realized, as we said, using two techniques: photogrammetrical survey and terrestrial digital laser scanner. In the portal the frieze is attributable to the Baroque style, while the molding has Rococo style features. The use of the photogrammetry has been finalized to the virtual reconstruction of the aforesaid portal, of which only lateral pillars and parts of the decoration are present in situ; the other elements found by the archaeologists have been summarily recomposed in laboratory. The photogrammetric survey has been performed on every element, moreover with the aid of the laser scanning survey, we have performed the resetting of the frieze, so that the whole portal has been semi-qualitatively reconstructed on the base of precise measurements. The visualization of this element could be used for future interventions of portal restauration.