Structure from Motion with Line Segments under Relaxed Endpoint Constraints

We present a novel SfM pipeline which estimates motion and wiry 3D structure from imaged line segments across multiple views. Though the position of lines can be determined more accurately than point features, the issue of detecting stable endpoints diverted most research focus away to point-based methods. In our approach, we tackle this problem by utilizing relaxed constraints on the endpoint positions both during matching as well as in the Bundle Adjustment stage. Furthermore, we gain efficiency in estimating trifocal image relations by decoupling rotation and translation. To this end, a novel linear solver for relative translation estimation given rotations from five line correspondences in three views is introduced. Experiments on long sequences show that our line-based SfM pipeline advantageously complements point-based methods, giving more meaningful 3D representation for indoor scenarios.