[Feature] Merge Faces from Metadata with detected faces

[hjed]

I have searched the existing feature requests to make sure this is not a duplicate request.

• Yes

The feature

In #4348 immich implemented reading face metadata from files.

These faces show up in the people view, etc but they are often duplicated with immich's own detected faces. When there is a significant overlap with an ML detected face immich should merge the detected faces with the one provided by metadata (and ideally their linked groups too).

My observation is that most detected face bounding boxes detected by digikam very closely match the size and shape of the bounding boxes generated by immich for the same faces so this would be very useful for portability.

Platform

• Server
• Web
• Mobile

[tye-mustafa]

my guess the tags come from xml are bad i tried with Lightroom and exported it to immich ended up same,

[hjed]

The ones from digikam work great except they don't merge with the autodetected ones which is really annoying because it means to use immich's better algorithm I'd have to go through a retag all faces (and having gone through this with several over programs and since immich doesn't support exporting faces its a big time sink that I'll have to do again next time I change programs w/ the associated data loss, etc with that)

[5TDg9]

Is this really needed? This is probably going to get a little bit messy... i would be statisfied, if the face tags generated by im mich woulde be just somehow "exportable" in a format, that other software Mike Digikam is able to read vor extract.
Instead of merging two face tags from immich and from another software Mike Digikam, they could surely co-exist both in the XML-File with an special description-tag like mentioned here
(how mylio is doing it). This would be lot easier to implememt than the merging.

[hjed]

It means that every face has to be retagged in immich at the moment to use the immich features and is duplicated in the UI. The data should be portable.

[rhatguy]

I think the way forward for something like this is a comparison from a % of size perspective. For example if Immich detects a region that overlaps say 90% (guessing at an appropriate % here) with a region from metadata, it should assume those two faces are the same. Using a % should help with different size faces rather than an absolute like number of overlapping pixels.

It would be super nice if Immich had a function somewhere that could report these overlaps and "correct" them if the user confirmed. For example, metadata said this face was here....Immich detected it here (overlapping by 90%). If user confirms, update the pictures metadata to match Immich's face region.

[dnnr]

For what it's worth, digikam internally appears to do a very similar thing. Sometimes there can be multiple face regions (detected but unrecognized) on the same face, so that they overlap by a lot. If the user assigns a specific name to one of them, the other one disappears. Maybe it's worth checking their implementation for how they decide this?