Photonix doesn’t make any changes to your existing photos – it only generates tags and other data in it’s own database. If you upload photos through Photonix’s web or mobile interfaces then Photonix will add the uploaded files to your photos folder but they will remain unmodified.
If you want to be extra certain that Photonix can’t modify your photos you can bind the folder as a read-only Docker volume using something like
-v volume-name:/path/in/container:ro in Docker run or adding
:ro to the end of a volume path in your