Rigidity constraints across two views under weak perspective

Bennett et al. (1989) proposed an algebraic condition for four point pairs in two views to be projected orthographically by the same rigid object. This paper presents an approach that extends the rigidity condition to two views not projected with the same scaling factors. The approach also allows generalization of the rigidity condition to cover n point pairs in two views naturally. In particular the condition when the object is planar is discussed. Such rigidity constraints would find applications in stereo matching and object recognition