3D spectroscopic mapping tomography applied to art objects diagnosis

In this work, acoustic microscopy, infrared reflectance spectroscopy and imaging, Raman and microRaman spectroscopy is used in order to study the stratigraphic structure of a painted art object. The tomographic images in a region of interest (ROI) of the art object is acquired using acoustic microscopy and the distribution of the materials in the ROI is acquired using infrared reflectance and raman spectroscopy. Using the acquired spectra from both the spectroscopies (Infrared and Raman) the 3D segmentation – clustering of the spectra dataset acquired from the ROI of the painted art object in order to display in high resolution the distribution of the materials in the stratigraphy. The clusters are consisted of spectra that have similar characteristics (for both the modalities Infrared and Raman) and thus are indicating the existence of similar materials; hence, similar chemical composition. The spatial distribution of such clusters can be illustrated in pseudocolor images, in which each pixel of image is colored according to its cluster membership. Such mapping images convey information about the spatial distribution of the chemical substances in an object.