Abstract
This paper describes the detection algorithm of the concrete ridge which have three items, aimed ridge, end ridge and side ridge. Candidate points of the edge of each ridge were detected by the differential calculus processing with remodeled Kirsch operator. Only connect ingredients of ridge line were detected using the simple processing of the labelling and the clustering. If the end of the ridge in the image of the aimed ridge was detected, the clustering operation was done until the end of ridge. The most part of the noises were removed by detecting the position of the ridge line about the end ridge before the clustering operation. After the clustering operation, the ridge lines were easily detected by the Hough transformation. If the end point of the aimed ridge was detected, the ridge line of the end ridge was drawed from the end point of the aimed ridge.
