Line detecting method using two rectangular windows passing through the line to be detected

摘要

In the preparatory stage, among all possible lines in two rectangular windows (12) and (14), assuming dust, a flaw or the like to be a part of a line, the most valid one is recognized as a line, and the inclination and characteristic values of the line are obtained, and then each rectangular window is deformed into a parallelogram-shaped window along this inclination. In the detecting stage, the inclination and characteristic values of the line to be detected are obtained by use of the parallelogram-shaped windows. Thus, even if image data is inferior, the detection of a line is possible, so that it is possible to detect a weld line, an edge of an object of detection, etc. with high accuracy.