Facebook Uses Face Recognition To Help Tag Photos


It’s no secret that Facebook’s Photo product is the most popular photo sharing service on the web by a huge margin. And one of the key features that made it so popular has been tagging, which lets you associate your friends with the photos they’re in — Facebook says that 100 million photo tags are added every day. Which is all the more amazing given that tagging is kind of a pain. Fortunately it’s getting better.

Back in October Facebook launched a feature that had some face detection built in — if someone appeared in multiple photos in the same album, Facebook would group them together and ask you who that person was, allowing you to tag them in one fell swoop. Now it’s improving on that by using face recognition technology to guess who the person is, using your network of friends as a reference.

Of course, any time the words “Face recognition” and Facebook are put together, there are going to be questions about privacy. Facebook VP Product Chris Cox says that the new feature complies with all relevant laws, and that users are given a choice of opting out of it entirely (i.e. your name won’t be suggested in the ‘tag your friends’ dialog, though your friends can still add it manually).

He also says that the technology couldn’t currently be used for any kind of site-wide face search, because it’s reliant on your social graph. Because you’ve got a fairly small number of friends, and typically appear in photos alongside an even smaller number of those, Facebook doesn’t need to be super accurate when it’s matching faces. Cox guesses that most people won’t even notice that the feature is active, though there will be an announcement at the top of the tagging screen.

The new face recognition technology will be rolling out to 5% of users next week, and will ramp up gradually after that. It’s also worth noting that Facebook licensed some of the technology it used to build this (it wouldn’t say from whom), and built some of it in-house.