End-to-end processing of passive thermography sequences from outdoor concrete infrastructure inspection

Abstract

This study developed an end-to-end procedure to overcome common issues faced during the analysis of passive infrared thermography (IRT) sequences from outdoor concrete infrastructures. The processing pipeline includes the automatic pre-processing of raw thermograms, data cleaning and organization, image adjustment, and sequential image registration. One image registration method was implemented, and the results were evaluated using the Euclidean distance metric. Furthermore, the resulting sequences were processed using signal processing techniques to increase the detectability of the defects. The results from outdoor IRT surveys over two academic samples are presented, where one image per minute was taken for 24 hours on slabs and columns representative structures. By addressing the difficulties encountered during the analysis of passive IRT sequences, our contribution can broaden the spectrum of the application of IRT for the condition assessment of concrete infrastructure.