added openmvg doc

config/openmvg_win.yaml

@@ -1,4 +1,3 @@
 general:
-  OS: windows
   path_to_binaries: C:\Users\threedom\Desktop\OpenMVG\ReleaseV1.6.Halibut.WindowsBinaries_VS2017\ReleaseV1.6.Halibut.WindowsBinaries_VS2017
   openmvg_database: C:\Users\threedom\Desktop\OpenMVG\ReleaseV1.6.Halibut.WindowsBinaries_VS2017\ReleaseV1.6.Halibut.WindowsBinaries_VS2017\sensor_width_database\sensor_width_camera_database.txt

docs/openmvg.md

@@ -1,3 +1,32 @@
 # Use with OpenMVG
 
-**Page under construction...**
+DIM can export matches in OpenMVG-compatible format and execute a comprehensive SfM reconstruction. All intermediate and final OpenMVG data are stored in the project folder specified with the `--dir` option, within the results folder for the current pipeline, under the openmvg subfolder.
+
+To run OpenMVG processing pass to `--openmvg` option the configuration file that containes path to the binaries and run for instance:
+
+```
+python ./main.py --dir ./assets/example_cyprus --pipeline superpoint+lightglue --openmvg ./config/openmvg_win.yaml
+```
+
+An example of openmvg configuration file for windows:
+```
+general:
+  path_to_binaries: path\to\OpenMVG\ReleaseV1.6.Halibut.WindowsBinaries_VS2017
+  openmvg_database: path\to\ReleaseV1.6.Halibut.WindowsBinaries_VS2017\sensor_width_camera_database.txt
+```
+
+An example of openmvg configuration file for linux:
+```
+general:
+  path_to_binaries: null # If None, the binaries are assumed to be in the PATH
+  openmvg_database: null # If None, it will be downloaded from the openMVG repository
+```
+
+Camera model for openmvg can be specified in `config/cameras.yaml`:
+```
+general:
+  camera_model: "pinhole" # ["simple-pinhole", "pinhole", "simple-radial", "opencv"]
+  openmvg_camera_model: "pinhole_radial_k3" # ["pinhole", "pinhole_radial_k3", "pinhole_brown_t2"]
+  single_camera: False
+```
+Cameras can be shared between all the images (`single_camera == True`), or each camera can have a different camera model (`single_camera == False`).