| 摘要 |
PURPOSE:To position a bead correctly into a specified position by making the image of a window part binary with an appropriate luminance level as the threshold value, thereby enabling the detection of image regions corresponding to the side end faces of the bead. CONSTITUTION:A window part 14 is to have the image of the inner peripheral surface of a positioning object pipe 1, and the side end face and upper face of a bead 13. At this time, the side end face of the bead 13 is different in the angle of reflection to the light source of an eye lamp 7 from the upper surface of the bead 3 and the inner peripheral surface of the positioning object pipe 1 and thereby has the luminance different from that of the other regions, so that image regions 15, 16 corresponding to the side end face of the bead 13 are detected by making the image of the window part 14 binary with an appropriate luminance level as the threshold value. The respective center-of-gravity positions of the image regions 15, 16 corresponding to the side end faces on both sides of the bead 13 are computed, and an intermediate part between the center-of-gravity positions is computed as the center position of the bead 13 by an image processor 8 for positioning. The bead 13 can be thus positioned correctly into a specified position. |
