I would particularly be interested in self-hosted solutions that still support image recognition, which is very useful for large libraries. Does such a thing even exist?
If you use macOS, you can use Apple Photos (with its client-side image recognition) without using iCloud for storage. Just put your Photo Library bundle-directory on a NAS instead, and then either sync it to your local machine, or work with it over SMB.
(Or, for optimal performance, the hybrid solution: put the library in a sparsebundle disk image, put that on the NAS, and then mount the disk image over SMB. This is what Time Machine does under the covers, because it vastly improves the overhead of filesystem operations over directly manipulating the files in SMB.)
This is what I currently do, but it doesn't expose the output of the object recognition to me. You have to guess what objects it might be able to recognize, and then search for them. I'd rather have the raw data.
(It's also frustrating that the VoiceOver image recognition is far superior to Photos', but is inaccessible to the Photos app.)
