Study of optical tag profile of the tag recognition measurement system in cultural heritage

tThis study exposes the process to identify the optimum optical tag profile to be used for monitoringthe minimum relative displacement of two areas of the artwork. The purpose is to realize an efficient,precise, and accurate structural monitoring system with minimal invasiveness. In particular, it is designedto determine the enlargement of a crack on a fresco inside a closed environment, such as inside a church.Theoretical studies and measurements in a controlled environment are performed to identify the bestmathematical distribution to be used as tags. The two small adhesive tags are the main components of thesystem, they are attached on the surface of the artwork and the acquisition of their images is performedthrough a high-resolution camera. An advanced least-squares fitting of quadratic curves and surfacesalgorithms for the objective function are used to detect the relative distance between these optical tags.The appropriate parameters for monitoring potential cracks on cultural assets are determined with afitting algorithm of an objective function. In this study, different bi-dimensional objective functions areconsidered to identify the best configuration.