Development of a UV to IR extension to the standard colorimetry, based on a seven band modified DSLR camera to better characterize surfaces, tissues and fabrics

Starting from the standard colorimetry, as defined by the International Commission on Illumination - CIE, we propose an enhanced approach to add near UV and near IR sides to the usual visible electromagnetic spectrum, extending standard XYZ colorimetric coordinate to 7 values, calculated with a revision of the Color Matching Functions (CMF) that we called Hypercolor Matching Functions (HMF). We used a modified digital reflex camera and a set of optical filters to realize such a system and we measured 7 band based colorimetric distances among several pigments, that, compared to distances calculated in the XYZ space, resulted into a better and more reliable separation among reflectance spectra.