| 摘要 |
PURPOSE:To measure a center position of a circular hole precisely even when a rough part due to noise and the like appears on a hole edge of an image of the circular hole photographed by a camera. CONSTITUTION:Hole edge points 1-8 of plural circumference directional positions corresponding to a hole edge of an image of a circular hole are picked up so that their coordinates are detected. The predetermined circular area taking an image center of gravity G of the circular hole as a center is set, while a hole edge point 5 situated out of the area is eliminated as a position situated in a part of an abnormal image. On the basis of the coordinates of the rest of the hole edge points, a recursive ellipse S, which indicates the image of the circular hole, is found. This recursive ellipse S matches the normal image of the circular hole, so that the center position of the circular hole can be precisely found from the center coordinates of the recursive ellipse. |
