Characterization of the evolution of indigo blue by multispectral imaging

Indigo blue is a natural organic color from the Indigofera tinctoria plant. It insoluble in water and does not require mordant to fix color; therefore, due its nature it can be considered as pigment or dye. The identification of indigo cultural heritage very difficult complexity chemical formula changes that undergo certain conservation exposition conditions. For this reason, characterization possible degradation, transformation, reaction processes essential for identification. In study, multispectral imaging has been used first time noninvasive technique characterize aging state using samples aged controlled climate chamber under extreme conditions humidity, temperature, light. proven promising application, together with classification techniques based on machine learning approaches.