Mapping of XRF data onto the surface of a tomographically reconstructed historical sculpture

Abstract

Historical wooden sculptures were usually decorated using so-called polychromy, which consists of decorating in a variety of colors. It is also common that such artifacts have been renovated several times by applying additional layers of material. Currently, restoration approaches tend to return historical artifacts to their original appearance. Therefore, it is highly desirable to investigate the material composition of the existing polychromy. Obviously, information about possible reparations and hidden defects is required as well. It is relatively easy to explore the internal structure of wooden sculptures by utilizing X-ray computed tomography. Standard X-ray fluorescence analysis is typically only performed on several selected spots of the sculpture. On the other hand, X-ray fluorescence imaging can presently characterize the whole artifact surface, although the interconnection between the 2D fluorescence image and the 3D sculpture is not so straightforward in general. It will be shown in this work, that data fusion based on a combination of X-ray fluorescence imaging and computed tomography can provide complex information about the wooden sculpture investigated.