This may be deemed slightly off topic but I felt like this community might know the answer to this. I'm looking for a way to permanently embed information about who is in a photo, but when I search Google I just get some forum posts from 10 years ago. Surely there is something more recent? How would you go about doing this? Let's assume they are JPG.
I thought about this when looking through photos from my grandparents, where the names are written on the back of the photo. I have many digital photos from ten years ago and I've already forgotten the names of some of the people so imagine what it will be like in another 30 years.
darktable used xmp, and that looks like an alternate metadata format, it looks like exiftools might be able to work with the xmp standard, and it looks like there's some face tagging features in xmp.