Eur. Phys. J. Plus (2021) 136: 958
https://doi.org/10.1140/epjp/s13360-021-01909-8

Regular Article

Integration of multispectral imaging, XRF mapping and Raman analysis for noninvasive study of illustrated manuscripts: the case study of fifteenth century “Humay meets the Princess Humayun” Persian masterpiece from Louvre Museum

¹ DEIM Department, University of Tuscia, Viterbo, Italy
² Centre de Recherche et de Restauration des Musées de France (C2RMF), Paris, France
³ UMR 8247 PCMTH CNRS, PSL Université IRCP, Paris, France
⁴ Musée du Louvre, Paris, France
⁵ Profilocolore Srl, Rome, Italy

^a c.colantonio@unitus.it

Received: 8 November 2020
Accepted: 26 August 2021
Published online: 20 September 2021

Abstract

The famous Persian illustrated manuscript’s page called “Humay meets the Princess Humayun” from Louvre Museum was investigated using multispectral imaging, X-ray fluorescence mapping and Raman spectroscopy for a deepen study of its constitutive materials and painting techniques and to evaluate the state of conservation of the artwork. Cross image treatments were also performed in order to extract further knowledge from the artwork. Due to the extreme fragile nature of the object and its outstanding value in the collection of Louvre’s Department of Decorative Arts, noninvasive and contactless diagnostic methods were chosen. Hypercolorimetric Multispectral Imaging (HMI), a portable 7-band multispectral system and its native digital image processing (DIP) software for image treatment, was used to integrate X-ray fluorescence (XRF) imaging mapping to multispectral and colorimetric dataset. It allowed to study the rich color palette, identify original materials and restoration interventions and eventual degradations of both pictorial layer and ancient paper. Punctual Raman spectroscopy was performed to confirm hypotheses of pigments characterization made on infrared and ultraviolet false color images (IRFC, UVFC). Image treatments crossing multispectral data and analytical punctual techniques investigated possible correlation between datasets providing interesting and easy-to-read distribution maps for chemical elements, which are characteristic for pigment identification. In particular, pigments not detectable through XRF for light-element limit of detection as ultramarine blue (lapis lazuli) and organic dyes were successfully identified and mapped. This integrated approach of multisource imaging data is a valuable tool for restorers and conservators, encouraging new protocols of noninvasive diagnostics for cultural heritage.