Summary: In the paper a scheme for finding the normal direction of planar faces from two perspective views is reported. Two perspective views of an object lying on the table are taken from two different viewpoints, with parallel viewing direction. Both the images are analyzed to extract lines and a connected topographic structure of the view. The different lines in the two topographic structures are corresponded. The corresponding lines in the two views can be considered as the projection of parallel lines in space. Hence for each visible face, corresponding line sets and their vanishing points are identified. The 3D direction of the lines are related to vanishing points by a simple relation. The cross product of the 3D direction of any two nonparallel lines belonging to a face determines its normal. This information is made use of in deciding concave, convex edges and is incorporated into the relational graph structure representing the view of a object.