2019. Vol.22. No. 1, pp. 50-54
On the Use of Advanced Post-Processing Imaging Tools for Studying Marquetries via Infrared Thermography
|Marquetry and/or inlay are synonyms that sometime engender confusion in term of definition. To the best of our knowledge, the earliest evidence for such technique used into the cultural heritage field is a casket found in Mesopotamia, dated back circa 2600 BC. Such artistic objects are subjected to the normal environmental aging. Defects — due to mechanical, physical, chemical, biological factors — may occur at different depths and can be considered a natural consequence.
Since they are multilayered structures, defects can be present at the various interfaces. On this basis, an intarsia panel containing fabricated defects was manufactured. It has three detachments not visible to the naked eye and an inclusion of foreign material (resembling a restoration procedure) on the decorative layer. The sample was inspected by infrared thermography method. The hot air stimulus was selected in order to make visible the defect signatures into the long-wave infrared spectrum. With the aim to improve the quality of their detection, advanced post-processing imaging tools were applied to raw thermograms. Among these, the principal component thermography (PCT), the sparse principal component thermography (SPCT), the higher order statistics thermography (HOST), the thermographic signal reconstruction (TSR), and the independent component thermography (ICT) techniques were used. Finally, a signal-to-noise ratio algorithm was applied in order to evaluate the improvement of the mutual performances.