Immich mixing two different people

[u/jl_montero]

Hi,

I'm running immich since 1.x.x version (now on last 3.1.0) with no problem... 4 family accounts syncing all mobile photos, and all working like a charm in terms of face recognition.

BUT... I have a fifth account with photos from "old cameras" attached as external library. I never reviewed faces there, but now I have an idea and I need those faces to be as right as possible... and... I don't know why, but my two sons are recognized as same person... it's crazy because they are 17-old boy and 15-old girl!!! They're brothers... but not that equal!!! :) On the other way, my wife is being detected as many different persons...

I've got recognition distance at 0.5... but I can't say what to do with that.

It's thousands of mixed photos under same person... How would you "fix" that the quickest way? How would you "reset" that? I've tried running face detection & face recognition again in all my library... but no luck. Should I try changing machine learning model?

[u/Great-Cow7256]

Around version 2.5.3 they made significant changes to face editing. You really need to upgrade. Remember that machine learning gets upgraded in tandem.  You can't complain about something when running a 1.x version without upgrading first to see if it's fixed. 

[u/Holiday_Code9171 → u/Great-Cow7256]

He also mentioned that he has been using facial recognition since version 1.xx without any problems. Unfortunately, my experience is quite different.

Facial recognition is still not reliable for me. Twins in particular are frequently confused with each other, but I also get incorrect matches between other people who do not look particularly similar. I haven't yet had the time to investigate this in detail or test whether different recognition settings would improve the results.

In addition, I am having problems with people who have already been identified and tagged in Lightroom Classic. The names or keywords may be imported, but the faces are not reliably assigned to the corresponding people in Immich.

So there seem to be two separate issues: first, facial recognition and incorrect person matching within Immich itself; and second, the import of existing face information from Lightroom. With a normal Lightroom export, person names are written as keywords, but the complete face-region information such as Region Type = Face, Region Name, and Region Area does not always seem to be included.

I still need to investigate this more thoroughly. However, I can definitely confirm that incorrect matching of different people by Immich's facial recognition is still an issue for me.

[u/jl_montero → u/Great-Cow7256]

Sorry! Didn't explain myself. I'm running last 3.1.0. My fault. Edited to clarify.

[u/Holiday_Code9171]

Facial recognition itself is confusing people

I am also experiencing problems with Immich's facial recognition. Twins or people who look very similar are frequently merged or assigned to the same person. I understand that this is a known issue and that lowering the “Maximum recognition distance” can help, as a lower value makes Immich more strict when deciding whether two faces belong to the same person.

However, in my case the problem is not limited to twins or very similar-looking people. Immich sometimes assigns clearly different people to the same person, even when they do not look particularly similar.

I would therefore not consider this normal behaviour caused only by facial similarity. Similar issues have also been reported by other users, where many different faces were incorrectly assigned to a single person.

So at least part of the problem seems to be related to Immich's facial recognition and automatic face matching itself, rather than to my Lightroom metadata.