Accuracy verification and enhancement in 3D modeling: application to Donatello´s Maddalena

The three-dimensional acquisition and modeling of Donatello´s Maddalena was started in order to create a methodology that aims at monitoring fragile wooden sculptures over the years. Hence a set of new approaches in 3D modeling was needed for obtaining the necessary metric reliability. The main focus of the work is modeling accuracy, therefore quality control procedures based both of the self check of 3D data and the use of complementary 3D sensors were developed for testing the model. Sensor fusion was also extensively used in order to correct a few alignment errors after the ICP phase leading to a not negligible overall metric discrepancy. All the steps of the acquisition procedure, from the project planning to the solution of the various technical and logistical problems are reported. Although few commercial systems claim to use a similar approach, for the first time, the noninvasive integration of photogrammetry and 3D scanning, specifically designed for applications in cultural heritage, is extensively documented here.