Dr. Pierre BOHER, R&D application Director of ELDIM will presente june 21st 2007 at SPIE Europe Optical Metrology:

Cost effective spectral imager for work of art characterization

Many efforts have been made recently to image a work or art at different wavelengths. Indeed, spectral reflectance has been used for a long time to characterize precisely the physical properties of any surface. In the case of a painting for example, multispectral measurements can provide precise information on the pigments and the varnishes. Multi-spectral cameras dedicated to these applications have already been developed for example in the frame of CRISATEL[1]. With 13 bands pass filters and very high resolution CCD sensor, this laboratory system provided interesting results but was too expensive for routine use in museums and institutions.   

In the proposed paper, we present a new system for easy and powerful spectral imaging of any work of art. Build around a low cost CMOS sensor, this instrument presents an easy and cost effective solution for spectral imaging in the visible range. The instrument development was made in the frame of a European project FING-ART-PRINT[2] for non contact high resolution finger print of objects of arts. The finger print itself consists of roughness data measured by confocal profilometry and reflectance spectra measured with our instrument. The system includes a Peltier cooled 1M pixels monochrome CMOS sensor, a series of 31 band pass interference filters, an imaging objective and a white LED illumination ring. All parts are integrated in a small volume and the acquisitions are made automatically true USB connection using a PC. The proposed paper will present the new system in details with some examples of measurements on various works of arts. The problem of the finger print taken with this technique will be also examined.