https://github.com/colmap/colmap/blob/ff8842e7d9e985bd0dd87169f61d5aaeb309ab32/src/colmap/sensor/models.h#L197
// Simple Pinhole camera model. // f, cx, cy CAMERA_MODEL_DEFINITIONS(0, "SIMPLE_PINHOLE", 3) // Pinhole camera model. // fx, fy, cx, cy CAMERA_MODEL_DEFINITIONS(1, "PINHOLE", 4) // Simple camera model with one focal length and one radial distortion // parameter. // f, cx, cy, k CAMERA_MODEL_DEFINITIONS(2, "SIMPLE_RADIAL", 4) // Simple camera model with one focal length and two radial distortion // parameters. // f, cx, cy, k1, k2 CAMERA_MODEL_DEFINITIONS(3, "RADIAL", 5) // OpenCV camera model. // fx, fy, cx, cy, k1, k2, p1, p2 CAMERA_MODEL_DEFINITIONS(4, "OPENCV", 8) // OpenCV fish-eye camera model. // fx, fy, cx, cy, k1, k2, k3, k4 CAMERA_MODEL_DEFINITIONS(5, "OPENCV_FISHEYE", 8) // Full OpenCV camera model. // fx, fy, cx, cy, k1, k2, p1, p2, k3, k4, k5, k6 CAMERA_MODEL_DEFINITIONS(6, "FULL_OPENCV", 12) // FOV camera model. // fx, fy, cx, cy, omega CAMERA_MODEL_DEFINITIONS(7, "FOV", 5) // Simple camera model with one focal length and one radial distortion // parameter, suitable for fish-eye cameras. // f, cx, cy, k CAMERA_MODEL_DEFINITIONS(8, "SIMPLE_RADIAL_FISHEYE", 4) // Simple camera model with one focal length and two radial distortion // parameters, suitable for fish-eye cameras. // f, cx, cy, k1, k2 CAMERA_MODEL_DEFINITIONS(9, "RADIAL_FISHEYE", 5) // Camera model with radial and tangential distortion coefficients and // additional coefficients accounting for thin-prism distortion. // fx, fy, cx, cy, k1, k2, p1, p2, k3, k4, sx1, sy1 CAMERA_MODEL_DEFINITIONS(10, "THIN_PRISM_FISHEYE", 12)