A General Rank-2 Parameterization of the Fundamental Matrix

All the methods for estimating the fundamental matrix do not naturally exploit the rank-2 constraint. For these reason some few rank-2 parameterizations of the fundamental matrix have been proposed over the years. In general they can be or an over-parameterization (12 parameters) and being generally valid, or use a minimal set of parameters (eight) but do not cover all the rank-2 matrices. We propose a new rank-2 parameterization which uses only 9 parameters, one more of the minimal parameterizations, and covers all the rank-2 matrices.