Advanced documentaiton

[simogasp]

For users that need to export data or use it externally, some documentation is needed

• format of feature files
• format of matches files
• sfmdata is kind of self-explanatory (being a json) although it is worth mentioning that
  • the focal length is in mm (and how to get the pixel value that everybody else uses)
  • the principal point is an offset wrt the principal point
  • observations are stored in distorted coordinates (original extracted features)
  • the poses are stored as R and C, with C being the center of the camera, so that one needs to compute t = -RC to create the pose matrix
  • the order with which matrices are stored (column/row major) --> it should be column-major, default in eigen https://eigen.tuxfamily.org/dox/group__TopicStorageOrders.html
• the format required for the masks (naming must be the same as the original image or its id?)

[natowi]

https://github.com/Fraunhofer-IIS/camorph/blob/main/docs/sphinx/formats/Meshroom/Meshroom.md#sfm-file

https://github.com/Fraunhofer-IIS/camorph/blob/main/docs/sphinx/formats/Meshroom/Meshroom.md#camera-models