Enhancement of thermographic images of composite laminates for debond detection: An approach based on Gabor filter and watershed

Abstract Spacecraft structures use materials which require high stiffness and low mass. Subjected to high thermal and acoustic loads, their health is of utmost importance. These structures are vulnerable to debonding and delaminations which are identified as defects. Non-destructive way of inspecting these components is very essential to detect the debonding defects. Debond defects are not visible to naked eyes and hence conventional optical cameras will not serve the purpose of automating inspection. For this purpose, we have used thermography. Passing the thermographic images through stages like enhancement, segmentation and feature extraction by using techniques like watershed segmentation, active contours and texture classification through Gabor filter are attempted in this study. Defects are brought out which help in taking corrective steps to avoid failure of the materials during actual life of the spacecraft.