Could you please recommend any free photogrammetry software? I am processing drone aerial photographs with the aim of getting Digital Elevation Models (including Digital Ground Models if possible), as well as orthophotos and 3D models, but I don't know any fee option.
Thank you!
The following is a general purpose SFM:
https://colmap.github.io/
The following may be useful in your case:
https://3d-reconstruction-using-stereo-vision.soft112.com/
Refer the following for other popular free SFM:
https://pfalkingham.wordpress.com/2017/12/17/free-photogrammetry-software-review-2017/
VisualSfM is a great software package. I've been able to match lidar point density and accuracy using it. It's configurable, offers a GUI, and can export georeferenced points. http://ccwu.me/vsfm/
A good choice also is OpenDroneMap (https://github.com/OpenDroneMap/OpenDroneMap)
"VisualSFM" is a good option for point cloud generation (including the usage of GCP for georreferencing). Other option you may consider is the use of "LAStools" for point cloud filtering and classification ("free"). However, these software will not generate orthopho or true-orthophoto. Good luck.
There are general SfM software like VisualSfM, regard3D, Colmap, Meshroom etc which are free to use. For aerial photographs, you can also use Autodesk Recap for free with student license. But there will be limit on maximum number of photographs you can process at once and also you could be put in a queue for processing if the free servers are busy. If you ask me about commercial software, Agisoft Metashape produces quite good results.