A HYPER-SPECTRAL SCANNER FOR HIGH QUALITY IMAGE SPECTROSCOPY: DIGITAL DOCUMENTATION AND SPECTROSCOPIC CHARACTERIZATION OF POLYCHROME SURFACES

Image Spectroscopy (IS) in the UV-Vis-NIR spectral region is a well-established methodology for the non-invasive diagnostics and documentation of polychrome surfaces. This contribution illustrates a highperformance hyper-spectral scanner, specifically designed for diagnostics on paintings and flat polychrome objects. The system, based on a prism-grating-prism line-spectrograph connected to a silicon CCD camera, operates in the 400-900nm spectral range, with high spectral resolution (about 1 nm) and a spatial sampling of 0.1 mm over areas of about 1 m. Thanks to these characteristics, this hyperspectral scanner, recently upgraded with mechanical improvements and a new software interface, still represents a cutting-edge instrumentation for IS applications on polychrome surfaces. This work illustrates the characteristics of the instrumentation and presents review of noticeable results obtained in different cases-.studies.