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Updated: Oct 22, 2025

Subsurface Defect Localization by Structured Heating Using Laser Projected Photothermal Thermography
Published on: May 15, 2017
Extension of the Thermographic Signal Reconstruction Technique for an Automated Segmentation and Depth Estimation of
Alexander Schager1, Gerald Zauner1, Günther Mayr1
1Josef Ressel Centre for Thermal NDE of Composites, University of Applied Sciences Upper Austria, 4600 Wels, Austria.
Abstract:
With increased use of light-weight materials with low factors of safety, non-destructive testing becomes increasingly important. Thanks to the advancement of infrared camera technology, pulse thermography is a cost efficient way to detect subsurface defects non-destructively. However, currently available evaluation algorithms have either a high computational cost or show poor performance if any geometry other than the most simple kind is surveyed. We present an extension of the thermographic signal reconstruction technique which can automatically segment and image defects from sound areas, while also estimating the defect depth, all with low computational cost. We verified our algorithm using real world measurements and compare our results to standard active thermography algorithms with similar computational complexity. We found that our algorithm can detect defects more accurately, especially when more complex geometries are examined.

