We present a method for semantic labelling of edges and reconstruction of range data by fusion of registered range and intensity images. An initial set of edge labels is derived using a physical model of object geometry and shading. A final edge classification and range reconstruction are obtained using Bayesian estimation within coupled Markov random fields employing constraints of surface smoothness and edge continuity. The approach is demonstrated on synthetic and real source data, obtained from an active laser rangefinder. © 1993 Academic Press. All rights reserved.