Stereophotogrammetry

Stereophotogrammetry is a photogrammetric method that derives three-dimensional information from stereo image pairs or networks. By analyzing parallax—the apparent shift of features between images taken from different viewpoints—rigid-body coordinates of surface points can be triangulated using the known camera geometry.

The workflow typically requires calibration of the camera system to determine intrinsic parameters (focal length, principal point, lens distortion) and extrinsic parameters (camera pose). Images are rectified to align epipolar lines, correspondences are established between views (either sparse feature matching or dense correlation), and 3D coordinates are reconstructed to form a point cloud, surface mesh, or textured model. Georeferencing or other spatial referencing can be applied for mapping applications.

Applications of stereophotogrammetry span cultural heritage documentation, archaeology, architecture and civil engineering, industrial inspection and quality control, geology and paleontology, and forensics and medical anthropology. It enables capturing complex shapes with high accuracy and color information using relatively modest equipment compared with other 3D capture methods, and is adaptable to both close-range and larger-scale surveying.

Advantages include non-contact data acquisition and the ability to capture rich texture information. Limitations involve dependence on image texture and lighting, sensitivity to occlusions and movement, the need for careful calibration and image processing, and substantial computational requirements for dense matching and 3D reconstruction.