VISUAL EXAMINATION METHOD BY IMAGE PROCESSING, AND ITS DEVICE

摘要

PROBLEM TO BE SOLVED: To determine whether the whole or a part of a foreign substance is buried or the foreign substance adheres to the surface, in an article made of an optically transparent material. SOLUTION: In this visual examination method, the article B made of the optically transparent material is imaged by a TV camera 11. A first edge extracting means 28 extracts an edge from a binarized binary image using a threshold allowing extraction of contours of both a foreign substance F buried inside the article B to a contrast image and a foreign substance F exposed on the surface of the article B. A second edge extracting means 29 extracts an edge from the pixel higher than the threshold set so that the contour of the foreign substance F exposed on the surface of the article B is extracted and the contour of the foreign substance F buried inside the article B is not extracted. A determining means 30 determines that a removable foreign substance F adheres to the article B when the variation rate of the length of the edges extracted by the first edge extracting means 28 and the second edge extracting means 29 is a determination threshold or lower. COPYRIGHT: (C)2009,JPO&INPIT