Structure from Motion Using Structure-Less Resection

This paper proposes a new incremental structure from motion (SfM) algorithm based on a novel structure-less camera resection technique. Traditional methods rely on 2D-3D correspondences to compute the pose of candidate cameras using PnP. In this work, we take the collection of already reconstructed cameras as a generalized camera, and determine the absolute pose of a candidate pinhole camera from pure 2D correspondences, which we call it semi-generalized camera pose problem. We present the minimal solvers of the new problem for both calibrated and partially calibrated (unknown focal length) pinhole cameras. By integrating these new algorithms in an incremental SfM system, we go beyond the state-of-art methods with the capability of reconstructing cameras without 2D-3D correspondences. Large-scale real image experiments show that our new SfM system significantly improves the completeness of 3D reconstruction over the standard approach.