# Face Detection Questions ("Find Faces Again...", Starting Face Detection from scratch, etc.)



## mjs_sf (May 19, 2020)

Thank you to all of the helpful people here. I've learned so much from you

I have several related Lightroom facial recognition questions. Hopefully asking them all in one post won't be too confusing. I’ve looked here and elsewhere and haven’t found definitive answers.

*Find Faces Again...*

Does this start from scratch - forgetting all face regions and, when present, the names associated with those regions? Does this apply only to the selected photos?

Is this the way to restart face recognition from scratch? In other words, can I get Lightroom to remove & forget all face & region detection and all names associated with those regions?  I *think* “Find Faces Again…” with all photos selected and both of the “Skip” options turned off might do this. Can anyone confirm or correct this understanding?


*Face detection running unexpectedly*

Does face scanning run when looking at the people view, even if of the Catalog's “Automatically detect faces…” being off and even if Face Detection is paused in the activity view in the upper left corner? I have the Catalog value off and the activity area says Face Detection is paused. But if I look at the People few, the “Unamed People“ bar says “Looking for more people…“ and the number of people found keeps increasing. This apparently stops if I switch away from the People view and to the Grid view. 


*When too many faces are detect*

Is there a way, when looking at a photo in the People view, to tell Lightroom to delete all of the unnamed regions, or even all of the regions? Why: I have many pix with a large number of photos in them - e.g. team photos, crowded scenes. In these cases Lightroom finds as many as 20 faces in the same picture, and all but 1-2 of the are irrelevant

Alternatively is there a way to have Lightroom never scan some set of photos?


Thank you very much for your help,
Mike


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## johnrellis (May 20, 2020)

mjs_sf said:


> can I get Lightroom to remove & forget all face & region detection and all names associated with those regions?  I *think* “Find Faces Again…” with all photos selected and both of the “Skip” options turned off might do this.



That's correct. But note that contrary to what many hope, Find Faces Again won't improve face recognition -- assuming you retag all the same faces the same way, the algorithm will give the same answers.  (An exception is if you have just upgraded from LR 7.2 or earlier.)

If you're going to do this on many photos, be sure to make a catalog backup first, in case things don't work the way you expected.


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## johnrellis (May 20, 2020)

mjs_sf said:


> Does face scanning run when looking at the people view, even if of the Catalog's “Automatically detect faces…” being off and even if Face Detection is paused in the activity view in the upper left corner? I have the Catalog value off and the activity area says Face Detection is paused. But if I look at the People few, the “Unamed People“ bar says “Looking for more people…“ and the number of people found keeps increasing. This apparently stops if I switch away from the People view and to the Grid view.


What you observe is what I've always observed as well.


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## johnrellis (May 20, 2020)

mjs_sf said:


> Is there a way, when looking at a photo in the People view, to tell Lightroom to delete all of the unnamed regions, or even all of the regions? Why: I have many pix with a large number of photos in them - e.g. team photos, crowded scenes. In these cases Lightroom finds as many as 20 faces in the same picture, and all but 1-2 of the are irrelevant


Select one or more photos and go to People view. Then select all the faces in Unnamed People, right-click a thumbnail, and do Remove Face Region.  You can also do that with Named People faces.

You can use the Any Filter plugin to find all photos with more than (say) 5 unconfirmed faces:





I used that to find all the team/group photos I didn't want to face-tag.


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## Linwood Ferguson (May 20, 2020)

I've been digitizing old images lately and a big priority has been to do face recognition.  Some suggestions: 

Turn off the mass, do-everything opton (top left corner, pause it). 

Do one folder or collection or related subject at a time.  Just get the images shown in grid view, then click on the face icon on the bottom and it will run recognition on those images (if not already done).  The reason I suggest this is that usually faces are from a limited set of people on a similar group of images, e.g. a party or event or whatever.  So for the human involved it is easier when you expect certain faces, and when you have a bunch left you do not want to tag, just select all the remaining regions and remove. 

However, one thing I am finding is that LR misses a LOT of faces.  A lot.   So I then go into loupe with the face region option active, and look at each photo, and draw in any faces I want that it missed.  It's interesting that it might miss 100 faces entirely in a group, but usually gets only 1 or 2 non-faces incorrectly.  It's got a very high false negative rate. 

Doing it  group or folder at a time also makes it easier to completely ignore a set. You can just never go into it, or you can go into it, let it build the region list, then just remove all of them so it will not do it again.


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## mjs_sf (May 21, 2020)

johnrellis said:


> Select one or more photos and go to People view. Then select all the faces in Unnamed People, right-click a thumbnail, and do Remove Face Region.  You can also do that with Named People faces.
> 
> You can use the Any Filter plugin to find all photos with more than (say) 5 unconfirmed faces:
> View attachment 14604
> ...



Thank you very much for your help. I've learned a lot.

John, I'm hoping you can clarify something for me. I tried your instructions but I must be missing something. I [a] selected a single image in the filmstrip - the image has four tentative identification regions and one region without a guess.  switched to People View and [c] opened the Unnamed People section. Unfortunately for this use case the Unnamed People section has hundreds of entries. Based on your suggestion I was hoping it would have only five - which would make clearing very easy. Did I misunderstand or miss a step?

Thanks again for your help,
Mike


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## johnrellis (May 22, 2020)

Oh, I forgot that People View is a little "different" -- it shows you the faces for all the photos in the current source (folder, collection) regardless of what's selected.  So to delete the unnamed faces from a single photo, put it in the Quick Collection by itself, then select the Quick Collection, then go to People View.


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## mjs_sf (May 22, 2020)

johnrellis said:


> Oh, I forgot that People View is a little "different" -- it shows you the faces for all the photos in the current source (folder, collection) regardless of what's selected.  So to delete the unnamed faces from a single photo, put it in the Quick Collection by itself, then select the Quick Collection, then go to People View.



Thanks for your help!


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