Statistical data processing was performed on the spectra of a painting recorded in the near-infrared (near-IR) and visible (Vis) region by a totally nondestructive method. Results are discussed also in connection with colorimetric analysis.
A. Orlando, M. Picollo, B. Radicati, S. Baronti, and A. Casini, "Principal Component Analysis of Near-Infrared and Visible Spectra: An Application to a XIIth Century Italian Work of Art," Appl. Spectrosc. 49, 459-465 (1995)