Spectral variability of the optical properties of pictorial layers

The spectral variability of reflectance properties of pictorial layers can be caused by chemical parameters, such as the nature of pigments and binders, or by morphological parameters, such as the pigment concentration, the thickness of the layer or the size distribution of pigments. This work proposes a study of the influence of morphological parameters on reflectance spectra using both hyperspectral measurements on physical samples and reflectance spectra calculated using an optical model based on the four-flux model. The spectral variability is evaluated by comparing the spectra to a reference spectrum, thanks to the Kullback–Leibler Pseudo-Divergence.