Cracks do exist in a concrete building, and the reasons for cracks can be attributed to grouting, force actions, and concrete properties. Detecting existing cracks and monitoring their growth conditions is an important issue in structure health monitoring. This study proposed an integrated approach to fuse the thermal infrared images, high-resolution image, and acoustic tracking. Thermal infrared images can be used to record the surface temperatures. Those defect areas usually have their surface temperatures different from their neighborhoods. Those surface temperature differences can be an important clue to identify the defects. From the high-resolution images, cracks do occur at those discontinuities, and those discontinuities can be treated as the boundaries of the segmented regions. In this study, an approach based on considering the distributions of the segmented regions to segment the given high-resolution images to locate the boundaries of the segmented regions. Then, the defect map is generated by overlaying the thermal infrared image on the segmented regions such that the map can reveal the defect locations, and the surface temperatures can be another evidence to show the defects. Acoustic tracking is introduced to verify the results. All the defect information is stored in a 3D model such that a defect model can be established.
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