On the perspective projection of 3D planar-faced junctions

A method to determine the spatial orientation of a 3D planar-faced object from a single perspective view is presented. In this method the junctions, that is the concurrences of three object edges in a vertex, are considered as key features. A geometric constraint, related to the perspective projection of the object junctions, is shown and exploited to make the process faster and more efficient. In this way, the knowledge of only two parameters is sufficient to verify the object orientation in 3D space. A system of equations is proposed which define the orientations space for a junction as a subset of ℛ², instead of ℛ³ as in the previous literature