| Camera Models |
| ============= |
|
|
| COLMAP implements different camera models of varying complexity. If no intrinsic |
| parameters are known a priori, it is generally best to use the simplest camera |
| model that is complex enough to model the distortion effects: |
|
|
| - ``SIMPLE_PINHOLE``, ``PINHOLE``: Use these camera models, |
| if your images are undistorted a priori. These use one and two focal length |
| parameters, respectively. Note that even in the case of undistorted images, |
| COLMAP could try to improve the intrinsics with a more complex camera model. |
| - ``SIMPLE_RADIAL``, ``RADIAL``: This should be the camera model of choice, |
| if the intrinsics are unknown and every image has a different camera |
| calibration, e.g., in the case of Internet photos. Both models are simplified |
| versions of the ``OPENCV`` model only modeling radial distortion |
| effects with one and two parameters, respectively. |
| - ``OPENCV``, ``FULL_OPENCV``: Use these camera models, if |
| you know the calibration parameters a priori. You can also try to let COLMAP |
| estimate the parameters, if you share the intrinsics for multiple images. Note |
| that the automatic estimation of parameters will most likely fail, if every |
| image has a separate set of intrinsic parameters. |
| - ``SIMPLE_RADIAL_FISHEYE``, ``RADIAL_FISHEYE``, ``OPENCV_FISHEYE``, ``FOV``, |
| ``THIN_PRISM_FISHEYE``: Use these camera models for fisheye lenses |
| and note that all other models are not really capable of modeling the |
| distortion effects of fisheye lenses. The ``FOV`` model is used by |
| Google Project Tango (make sure to not initialize `omega` to zero). |
|
|
| You can inspect the estimated intrinsic parameters by double-clicking specific |
| images in the model viewer or by exporting the model and opening the |
| `cameras.txt` file. |
|
|
| To achieve optimal reconstruction results, you might have to try different |
| camera models for your problem. Generally, when the reconstruction fails and the |
| estimated focal length values / distortion coefficients are grossly wrong, it is |
| a sign of using a too complex camera model. Contrary, if COLMAP uses many |
| iterative local and global bundle adjustments, it is a sign of using a too |
| simple camera model that is not able to fully model the distortion effects. |
|
|
| You can also share intrinsics between multiple |
| images to obtain more reliable results |
| (see :ref:`Share intrinsic camera parameters <faq-share-intrinsics>`) or you can |
| fix the intrinsic parameters during the reconstruction |
| (see :ref:`Fix intrinsic camera parameters <faq-fix-intrinsics>`). |
|
|
| Please, refer to the camera models header file for information on the parameters |
| of the different camera models: |
| https: |
|
|
