Structure from Motion from Three Affine Views

We describe a new method for Structure From Motion from three affine views. The central idea of the method is to explore the intrinsic three-view properties instead of previous two-view ones. The first key observation is that an affine camera is indeed essentially a one-dimensional projective camera operating on the plane at infinity : we prove that the essential motion—relative camera orientations—is entirely encoded by the infinity 1D trifocal tensor. From a practical point of view, this analysis allows the development of two new algorithms of SFM from three views. One based on entirely the minimal trifocal tensor and another on affine three-view constraints. Both algorithms are novel as all previous SFM from three views have been heavily based on only two-view constraint to extract Euclidean structure. These algorithms have been demonstrated on real image sequences.