Supporting localization for new land areas via Mapillary

Dear all,

I would like to extend the vanilla OrienterNet system to support localization in a new area of land which, as always, is bounded by a large rectangular patch. The patch is defined by two points A and B with latitude and longitude coordinates. I want to use the Mapillary service to provide such a functionality in the OrienterNet.

To do this, if I am correct (please correct me if I am wrong), I first need to update the file at ./maploc/data/mapillary/splits_MGL_13loc.json which is internally copied into datasets/MGL once you call "python3 -m maploc.data.mapillary.prepare --token MYTOKEN". There, I have to create two new key-value pairs for the region I need to support.

Here are some basic questions:

1) How can we obtain the "image IDs" used in the definitions of areas such as in **sanfrancisco_soma**? What script is needed to obtain the image IDs corresponding to the rectangular patch of a new geographic area? Can someone point to a Mapillary snippet that does so (especially the one that was actually used by the developers of the OrienterNet to create entries for, e.g., sanfrancisco_soma)?

2) In the file ./maploc/data/mapillary/splits_MGL_13loc.json, what is the difference between two key-value pairs that are put under "train" and under "val"? In particular, how should the image IDs be obtained (collected/selected) for either case?

Many thanks in advance.