Modeling of 3-D Joint Set Interpretation In order to estimate rock joint parameters, such as strikes and dips which geologists often inspect on site andlor calculate through 3Djoint surface recognition by use of stereo-photo system, an image processing algorithm of joint set modeling which simply simulates their interpretation is designed. Comparing resultant parameters in Schmidt-net diagrams, it is confirmed that the algorithm based on an edge-base stereo matching can treat 3-Djoint parameters, while further enhancement of noiseless edge-detection algorithm has been needed. Procedure of 3-Djoint set interpretation can be broken down into three sequential stages: adoptive edge recognition. recognition of undulations on a rock surface, and estimation of joint surfaces. Since joints are revealed as edges in photo-images, these three stages can be realized to correspond to three procedures of edge-based digital image processing: edge extraction, edge-base stereo matching, and edgegroupin...