| 摘要 |
PROBLEM TO BE SOLVED: To provide an ellipse detection method and an ellipse detection device capable of detecting even a defect ellipse in a practical time by using two kinds of hough transforms. SOLUTION: This ellipse detection device executes pattern matching to all pixels in image data of a processing target by use of a previously stored mask pattern (S2-3) to estimate normal directions of edge pixels. Pairs of the edge pixels having the estimated normal directions different by 180 deg. are generated (S2-7), coordinates of the middle points of the generated edge pixels are found (S2-8), the coordinates are voted on a two-dimensional voting space by a method of the hough transform (S2-9). An integrated point in the voting space is detected (S2-11), coordinates of the center point of the ellipse are assigned to the integrated point is (S2-12), and the ellipse is detected on the basis of the coordinates of the center point. |
