Generating of damage maps of building façades through digital image processing captured by drones and use of digital photogrammetry

Abstract The aim of this study was to apply a methodology for automatic generation of maps of damages in orthoimages of façades, using UAVs to capture the photographs. The generation of maps of damages aimed to assist in the visual inspection method used in activities of maintenance, restoration or intervention in buildings. Using the dense stereo matching (DSM) method, geometric models of buildings weren generated by the point cloud in the PhotoScan program for obtaining orthoimages. After this step, the orthoimages were submitted to generation of maps of damages of staining in Tyche (2015) software, which mapped and quantified in percentage terms these defects. The results of the maps of damage were also classified qualitatively. The application of UAV proved to be an efficient tool for façade inspection activity and for capturing images to be used by DSM. The generation of maps of damages by Tyche (2015) proved also effective, however it was verified that the user interaction was important to achieve the expected results.