Can Facebook recognize faces?
Yes, Facebook can recognize faces and even recommends “tags” for people whose faces it recognizes. Facebook will look at your friend’s list and try to figure out if anyone in your friends list is in your photos and will suggest the names for tagging.
Facebook will also give you the option of removing the tags that it suggests in case you don’t want to tag that person or if Facebook is wrong in it’s suggestion.
What does this Face Recognition Mean?
Well, it means that Facebook has basically created a database that associates peoples’ names with their faces. And not only does Facebook have a database, they also have some facial recognition software that allows them to compare what they have in their database to the faces that they find in your photographs. Pretty amazing, no? Especially considering the fact that Facebook would have to narrow down it’s search to just one person – so if you have a lot of friends, then Facebook has to find the one person whose face matches the face in your photograph.
How could this algorithm work?
Well, this is speculation, but Facebook would probably start by looking at the people who you have tagged in photo’s recently before comparing to other people in your friends list. And, if you have listed someone as “Married/Engaged to” or “In a Relationship With”, then presumably Facebook would start looking at those people first, since those are the people you’re most likely to be tagging in photographs. Remember that this algorithm must be fast, otherwise there’s really no point in having it since people don’t like to wait for more than 5 seconds.
The other thing is that the face showing up in the photograph would probably have to be big enough and clear enough for Facebook to recognize – so long distance shots would be hard to apply this face recognition software to. So, close-ups are much easier to work with.