Fixing the Locally Optimized RANSAC

The paper revisits the problem of local optimization for RANSAC. Improvements of the LO-RANSAC procedure are proposed: a use of truncated quadratic cost function, an introduction of a limit on the number of inliers used for the least squares computation and several implementation issues are addressed. The implementation is made publicly available. Extensive experiments demonstrate that the novel algorithm called LO+-RANSAC is (1) very stable (almost non-random in nature), (2) very precise in a broad range of conditions, (3) less sensitive to the choice of inlier-outlier threshold and (4) it offers a significantly better starting point for bundle adjustment than the Gold Standard method advocated in the Hartley-Zisserman book.