3D Modelling of trompe l'oeil decorated vaults using dense matching techniques

Dense matching techniques, implemented in many software, both commercial or open source, are effective instruments to realize a rapid and detailed survey of complex objects, including many different surfaces and a lot of details. For this reason these tools have been tested for the metric survey of a frescoed ceilings of the hall of honour of a baroque building. These surfaces are densely painted with trompe-l'oeil technique, what, in theory, can offer a very good texture to automatic matching algorithms, but in this case the painting gives problems in reconstructing the correct geometry: in fact, in correspondence with principals architectonic painted details, the models presents some irregularity following the painted drawing. The photogrammetric models have been compared with data deriving from a LIDAR survey of the same object, to evaluate the entity of this blunder: some profiles of selected sections have been extracted, verifying the different behaviours of the software tool