Search

In this paper, we consider the possibilities of the stimulated infra-red thermography for local metallic sample thermal characterization. At first we introduce the measurement principle, which is based on the local measurement of the thermal diffusivity parameter. Then, using simulations, we demonstrate the feasibility of the method. We then present the experimental device implemented for the study. Finally, we show that this approach allows a good estimation of the thermal diffusivity of a metal sample. [ABSTRACT FROM AUTHOR]

In this article, various cases in helping to restore works of art by stimulated infrared thermography are presented. First, the method allows detecting old restorations found on a mural painting in the French senate. Then, it is demonstrated how the photothermal method enables determination of the underlying structure of the mural painting 'The Apotheosis of Saint Bruno' in the Charterhouse of Villeneuve-lez-Avignon. Finally, the method allows locating separate canvas paintings on 'Avenant de l'aurore' in the 'Luxembourg' French Senate building. [ABSTRACT FROM AUTHOR]

Health of ancient artworks must be routinely monitored for their adequate preservation. Faults in these artworks may develop over time and must be identified as precisely as possible. The classical acoustic testing techniques, being invasive, risk causing permanent damage during periodic inspections. Infrared thermometry offers a promising solution to map faults in artworks. It involves heating the artwork and recording its thermal response using infrared camera. A novel strategy based on pseudo-random binary excitation principle is used in this work to suppress the risks associated with prolonged heating. The objective of this work is to develop an automatic scheme for detecting faults in the captured images. An efficient scheme based on wavelet based subspace decomposition is developed which favors identification of, the otherwise invisible, weaker faults. Two major problems addressed in this work are the selection of the optimal wavelet basis and the subspace level selection. A novel criterion based on regional mutual information is proposed for the latter. The approach is successfully tested on a laboratory based sample as well as real artworks. A new contrast enhancement metric is developed to demonstrate the quantitative efficiency of the algorithm. The algorithm is successfully deployed for both laboratory based and real artworks. [ABSTRACT FROM AUTHOR]