TheiaSfM

Why we included this project

Theia, written by Chris Sweeney at UC Santa Barbara, is an end-to-end structure-from-motion library that takes raw photos through the whole reconstruction pipeline: SIFT feature extraction by default, two-view matching with geometric verification, and the global optimization that produces camera poses and a sparse 3D point cloud. What sets it apart from turnkey tools is how cleanly each pipeline stage is separated, so you can lift out the multiview geometry routines or plug in your own matcher and solver without reworking everything else. It is a C++ library for researchers and engineers comfortable building from source, and the permissive BSD-style license makes it easy for commercial teams to embed. If you have hit the limits of COLMAP or OpenMVG and want something modular you can reshape, Theia is a practical choice for photogrammetry and robot-vision work, with thorough documentation at theia-sfm.org.