Detection of incipient defects in book bindings. A functional use of the infrared vision combined with optical and nuclear magnetic resonance (NMR) spectroscopy techniques

Abstract

In this study, an ancient book dating back 1822 was inspected by infrared thermography method, working in the active modality. Data was processed by different techniques in order to reduce the impact of non-uniform heating and, in the same time, to improve the thermal imprint of the natural defects detected. In order to confirm the results obtained, both the holographic interferometry and the nuclear magnetic resonance (NMR) techniques were used. The results appear in good agreement among them. Finally, the book binding was also studied into the near-infrared spectrum, while the lateral hinge was inspected by speckle techniques.