| 摘要 |
PURPOSE:To detect a desired feature point at a high speed with high accuracy without mistaking it as a similar shape by setting logic for detecting the feature point previously after detecting a feature quantity determining the presence of the feature point and a closed curve and a feature quantity for retrieving it. CONSTITUTION:The feature quantity which determines the presence of the feature point 13 and the closed curve 16 which retrieves it are set. In a figure, the curve 16 are along a loop (a). The feature quantity is a bright part a half as large as the circumference of the curve 16 (b). The feature is retrieved counterclockwise and a dark part detected for the 1st time after the start of detection is the right point of a point 13(c). Then, calculation for adding an offset to the address table of the curve 16, etc., are performed. Then, picture element data are inspected according to the address table of the curve 16 to check the length of a continuous bright part. Then when the feature quantity is detected, inspection is performed on the curve 16 counterclockwise according to the logic (c) to inspect the position of the 1st dark part. The position of a 1st dark part is the right end of the feature point 13. Thus, the desired feature point is securely detected by said procedure. |
