Digital image analysis on cathodoluminescence microscopy images for ancient ceramic classification: methods, applications, and perspectives

This paper aims to investigate the application of cathodoluminescence (CL) imagery (with optical microscopy) and CL spectroscopy (with Scanning Electron Microscope) in ancient ceramics studies, for a proper classification of petro-fabrics and mineral inclusions based on their CL response. Digital image analysis (DIA) routines are proposed for both qualitative and quantitative analysis, and outcomes are reviewed in the light of classical optical microscopy (OM) and scanning electron microscopy (SEM-EDS) approaches. Obtained results demonstrated the suitability of CL in discriminating ceramic groups, offering also complementary information connected with aspects as provenance or manufacturing processes. CL imagery and spectroscopy data are also used to discuss perspectives of the method, debating bias, limits, or suspicious inconsistencies, exploring how compositional features or sample's nature imprint CL response, and finally providing the basis for future developments. Addendum at the back of the paper includes and extensively discusses some technical aspects regarding the applied DIA routines, developed in open-sources software environments and available as supplementary materials.