Materials monitoring for art and beyond

The value of Europe's cultural heritage legacy is appreciated by millions beyond European borders. It serves as an inspiration for art books, text books, and pilgrimages from within and beyond the continent's borders. Cultural heritage monitoring exploits advanced instrumentation, technologies and protocols to determine the effects of time and environment on the integrity of works of art with molecular precision.

Currently, different spectral bands are being investigated using different techniques. This requires manipulation, transportation and, generally, movement of the art, increasing the risk of damage or deterioration. The novel combined 3D and hyperspectral imaging system developed with EU funding of the project 'System for digitization and diagnosis in art applications' (SYDDARTA) will eliminate the need for handling while providing superior information.

Hyperspectral imaging combines spectroscopy and digital imaging. A hyperspectral camera produces an image in which each pixel simultaneously contains spectral information covering more than one band (of frequencies or wavelengths) of the electromagnetic spectrum. SYDDARTA combined 3D scanning techniques for volumetric digitisation with hyperspectral imaging in visible and near-infrared regions. A very narrow screening bandwidth was employed to enhance precision and accuracy.

The prototype consists of two optical channels for combined 3D digitisation and hyperspectral imaging data capture. The system implements advanced optical technology, including digital light projectors, acousto-optic tuneable filters, liquid crystal tuneable filters, and high-end focal plane array sensors working in the visible and short-wave infrared.

Data is processed to produce 3D point clouds and hypercubes directly related to the object's surface and chemical composition. The hyperspectral data are used for automatic classification to identify and quantify substances mixtures, deterioration and degradation as defined by the user.

Researchers successfully tested the SYDDARTA system on a collection of Baroque paintings. The system will increase the speed and accuracy of analysis while reducing the costs and likelihood of damage to the object under investigation. The technology is expected to have important impact on conservation and authentication of arts and heritage. Numerous other markets including agro-food monitoring, pharmaceutical development and quality control in manufacturing are foreseen as well.