Hello,
I have experience with QGIS, PostGIS, various formats (SHP, GeoJSON, KML, GPX) and libraries (pyproj, rtree, shapely, fiona).
I have also worked worked with many mapping platforms like Google, Here, Openstreetmap and I have georeferenced large images.
If I understand the project correctly you already have a file with GIS data about the graves but you need to match the photos to the file in order to fill in new attributes in the file.
What format do you already have / need the output to be in?
Best wishes,
iticus