The collection of reliable information for improving the design of underground excavations is a major problem in underground mines where boulders that detach from the rock mass can cause serious injuries and even death. This publication describes an image analysis system developed by the authors and adapted to the conditions in underground mines. The system consists of an automated discontinuity reconnaissance module based on photographs of the rock walls, the Rockscan module. A methodology for taking pictures in an underground environment was developed to maximize its performances. A fracture characterization module, the Mapscan module, was also developed to characterize the rock mass using the results obtained by Rockscan. Compared to the traditional method of discontinuity surveys, this technique offers many advantages: the time necessary for data acquisition is greatly reduced; the large number of data collected increases the quality of the information available for characterizing the rock mass; it allows the creation of a permanent database; it is simple to implement; and mainly, it avoids the operator’s direct exposure to falling boulders.