Applying Corner Detection Method in Dimensional Inspection

• Main Author: 汪德美
• Other Authors: 王茂駿
• Format: Others
• Language: en_US
• Published: 1991
• Online Access: http://ndltd.ncl.edu.tw/handle/28940436487397112216

碩士 === 國立清華大學 === 工業工程研究所 === 79 === This thesis includes four parts: First, a contour tracking method is introduced in order to obtain a sequence of integer-coordinate edge points. This is the preliminary task for corner detection. Secondly, a simple algorithm for corner detection is proposed. The method applies the concept of cancellation of the vector''s direction on both side (the forward and backward arms) of a point to detect corners. Comparing the results with that of the other corner detectors, the similar results are obtained. Our method is simpler in the computation of discontinuity. Thirdly, camera calibration proposed by Chang was introduced. The method involves two types of transformation: homogeneous and quadratic calibration. Besides, we develop a simple method to transform dimensions between the image plane and the real-world plane by using a transformation factor. Finally, two mechanical parts (i.e. screws and gears) are inspected by our comer detector. For external screws, we inspect three defects: the missing thread, the distorted thread and the thread without axial symmetry. For gears, we measure the pitch variance and the total accumulated pitch variance.