We provide a visual comparison between sparse matching perspective SfM and our proposed dense matching spherical SfM. In (a), ERP images are converted into a cubemap representation, after which feature matching is performed across all 36 possible image pairs, resulting in sparse and noisy correspondence matches. (b) demonstrates our approach, which directly finds dense and accurate correspondences on ERP images, thereby facilitating the construction of a detailed 3D structure.
By leveraging dense features on equirectangular projection (ERP) images, our method effectively finds correspondences in textureless regions, registers more camera poses, and reconstructs a greater number of 3D points.