Active thermography non-destructive inspection of a damaged artwork with a complex shape

This study reports the results of active thermography non-destructive inspection of an ancient artwork. The artwork was decorated with metal ornaments, realized by hands from specialized craftsmen. However, it was seriously damaged by a catastrophic event based on repeated vibrations. The condition of the ancient artwork was evaluated from thermal data recorded during and after a long pulse heating. In this study, the evaluations were performed using not only the raw thermograms but also the results of three post-processing algorithms, namely: pulsed phase thermography (PPT), thermographic signal reconstruction (TSR), and principal component thermography (PCT). Comparison of the results based on signal- to-noise ratio (SNR) calculations showed that TSR was the most effective technique for detecting defects, and PCT was also effective for the detection of crack-shaped defects. In contrast, PPT seems not suitable for inspection of objects with a complex shape.