We introduce a two-step iterative segmentation and registration method to find coplanar surfaces among stereo images of a polyhedral environment. The novelties of this paper are: (i) to propose a user-defined initialization easing the image matching and segmentation, (ii) to incorporate color appearance and planar projection information into a Bayesian segmentation scheme, and (iii) to add consistency to the projective transformations related to the polyhedral structure of the scenes. The method utilizes an assisted Bayesian color segmentation scheme. The initial user-assisted segmentation is used to define search regions for planar homography image registering. The two reliable methods cooperate together to obtain probabilities for coplanar regions with similar color information that are used to get a new segmentation by means of Quadratic Markov Measure Fields (QMMF). We search for the best regions by iterating both steps: registration and segmentation. Key words: interactive com...