| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a pipe inner surface inspection method whose detection accuracy of a flaw on a pipe inner surface is high and which requires less labor and cost, and a pipe inner surface inspection device. <P>SOLUTION: An annular lighting 3 is placed opposite an end surface 21 of a steel pipe 2 to nearly match a central shaft 32 of the annular lighting 3 and a pipe shaft 22 of the steel pipe 2, illumination light is emitted to an inner surface 23 of the steel pipe 2, a camera 4 is placed opposite the end surface 21 of the steel pipe 2 to nearly match a light axis of the camera 4 the pipe shaft 22 of the steel pipe 2, and images of the end surface 21 and the inner surface 23 are picked up. An inner surface image is extracted from the picked up images, and the inner surface image is divided into a plurality of annular areas in a radial direction. A reference range of density is set every divided annular area, and a group of pixels whose density deviates from the reference range is extracted as a group of flaw candidate pixels. Prescribed density defined for every annular area is subtracted from the density of pixel in the prescribed pixel including the group of flaw candidate pixels, a pixel area where density is subtracted is converted into a pixel area when viewed from the radial direction of the pipe inner surface, and it is determined on the basis of the converted pixel area whether or not there is a flaw. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
