Corrosion inspection of steel tube inner wall

Summary form only given. In order to maintain the safety of steel tubes which have been used as structural members in large scale structures for a long period, the inner wall of their tubes must be investigated periodically. There are several inspection methods including visual inspection which use an industrial endoscope, and visual inspection is practical to use. However, the methods often involve investigation of a lot of video tapes recorded in the field. The aim of the present study is to automate this visual inspection. We have paid attention to the color of the rust which appears in the corroded wall, and have tried to detect corroded regions by using color image processing. Moreover, we have developed a method to be able to inspect the observing video tape in real time by using a commercial high speed image processing board.