Google Photos does facial recognition on people’s backs

Facial recognition has been one of the hallmark features of Google Photos since the app’s release, but it’s recently gotten a lot more powerful. I’ve just noticed a silent improvement that has made Photos capable of recognizing the back of people’s heads as a person and tagging them correctly with the right name. This is happening regardless of whether I uploaded these pics to Google Photos a week ago or a couple of years ago.

I like taking photos of my husband’s behind. No, not like that! Since we started traveling more frequently, I found myself snapping pics of him walking, hiking, or standing in different environments. It’s like a diary of where we’ve been and what we’ve done. However, those photos were never recognized by Google Photos as pics of him. Actually, Photos never detected a face there — because, well, there is no face — and hence didn’t let me manually tag those pics. It was annoying, so I had to create a manual album to keep these pics together.

Today, however, I was surprised to see that a lot of these pics are now showing up under his face profile in Google Photos. The app is now clearly detecting the back of his head and, even more surprisingly, properly tagging him. How? I’m not sure, but I have a couple of ideas.

It could be a case of Google creating an entire model of his head based on videos and other partial-face photos and thus recognizing his unique head shape, hair, and cute (he forced me to write this) bald patch. It could also be a case of Google smartly associating other photos in the same time span with this one: If someone is wearing the same clothes, in the same location, in the same time span, it must be the same person, right? Or maybe it’s both of these plus other Machine Learning techniques we’re not aware of. I’ve reached out to Google to ask.

However, the tag here appears a little differently than in regular facially-recognized pics. It shows with the notice of “face available to add.” So Google seems to be hedging its bets, doing the work but still signaling that it might not be 100% right. You can tap to change the person tagged if it’s wrong or remove the tag altogether.

I also noticed a significant improvement in facial recognition for partial faces and masked faces. A lot of our 2021-2022 pics weren’t tagged before, even though our face was partially visible but masked. Now they are.

Does it work for all photos?

I’d say that about 80-85% of my husband’s pics from behind and other partial face snaps have been properly recognized. There are still some outliers, though.

In this example, Photos doesn’t even acknowledge that there’s a face from a close side angle (left pic), so I can’t even add a manual tag. That photo can’t show up with the other snaps of my husband. But in the same pic from a wider angle (right), he’s properly marked as a person — ha! — and correctly tagged.

In this other example of two photos taken in the same minute and place, Photos acknowledges the presence of a person in both but only correctly tags him in the right photo. I can manually add a tag in the left one, though.

I’m pretty excited about this improvement in Google Photos because it means that more pics of the people I love will be grouped together, regardless of whether or not their entire face is visible. I won’t have to go manually digging for them anymore. That’s super cool. A little uncanny, for sure, but very cool.