IRIS: A novel integrated instrument for co‐registered MA‐XRF mapping and VNIR‐SWIR hyperspectral imaging

Abstract The combination of complementary techniques for materials analysis can play a key role in both art conservation and academic research. Nowadays, the correlation of x‐ray fluorescence ( XRF ) with hyperspectral reflectance imaging in the visible and infrared region has become a valuable tool for palette identification, painting techniques studies and for the diagnostic support dedicated to restoration and conservation. Moreover, both techniques enable researchers to reveal fascinating underpaintings, “pentimenti”, or even preparatory drawings offering new details on the creative process of the artist. This background has been a strong motivation for the development of a new multimodal tool for art and conservation: IRIS . IRIS is a mobile and reconfigurable scanner designed to address a wide range of demanding application, exploiting the opportunities given by simultaneous MA‐XRF and hyperspectral reflectance scanning in the visible‐near‐infrared ( VNIR ) and short‐wave‐infrared ( SWIR ) range from 400 to 2500 nm. The system has been designed for in‐situ, fast and non‐invasive scanning of the sample without compromising spectral resolution and high throughput performance. The scanner acquires co‐registered XRF / VNIR‐SWIR data, thus allowing the user to obtain the maximum profit from their possible correlated information: the two techniques can provide enhanced or complementary information on the same spot of analysis with minimum effort in terms of data processing and no need for spatial alignment. In the present work, the qualitative and quantitative performance of IRIS are explored, together with the presentation of in‐lab analysis on reference samples and a brief insight on a real case‐study.