| 摘要 |
PURPOSE:To enable detection operation to be made easily and pattern position detection to be performed positively. CONSTITUTION:An image pick-up device 3 which allows a portion of a pattern 2 in symmetrical shape formed at a product to be detected 1 to be in a two-dimensional image, a symmetrical property operation means 6 which calculates the degree of symmetry of a pattern image of the pattern 2 at each position of the image. and a symmetrical position detection means 7 for detecting most symmetrical position according to a distribution of the degree of symmetry which is obtained by the symmetry operation means 6 are provided. |
