Innovative diagnostics through Hypercolorimetric Multispectral Imaging and Pulse compression Thermography to support the restoration of a 16th wall painting in Palazzo Gallo (Bagnaia, Italy)

Abstract

This paper summarizes the main results of the study, restoration and diagnostics applied to the 16 th century wall painting (a portion of the frieze and the Riario coat of arms) in Palazzo Gallo (Bagnaia, Viterbo -Central Italy) recently concluded and object of a master's degree work in Conservation and Restoration of Cultural Heritage. Innovative imaging techniques were used for the first time on a wall painting on-site: Hypercolorimetric Multispectral Imaging (HMI) and Pulse-compression Thermography (PuCT), combined with more traditional analysis. Multispectral imaging allowed for mapping the conservation status before and after the removal of the scialbo layer that covered the original paintings. It also allowed to compare between different areas of the painting and to verify the effectiveness of the cleaning. PuCT allowed to detect cracks and discontinuities in the ground layers and to evaluate the depth of such anomalies giving a valuable support in the consolidation step.