Methods for space line localization from single catadioptric images: new proposals and comparisons

Line localization from a single image of a central camera is an ill-posed problem unless other constraints or apriori knowledge are exploited. Recently, it has been proved that noncentral catadioptric cameras allow space lines to be localized from a single image. In this paper we propose two novel localization algorithms. The first method exploits a pair of coplanar viewing rays to localize the space line. The second method follows a constrained non-linear minimization procedure using a suitable parametrization to represent space lines. We compare the accuracy of the proposed method w.r.t. the classical line localization algorithm and two robust variants of it. We carried out both synthetic and real experiments and evaluated the performance in localizing a set of space lines. We also propose a quality index for the viewing surfaces associated to space lines in order to better evaluate the quality of the localization. The experimental results showed the effectiveness and the accuracy of both proposed methods.