This past weekend my little sister and I were going through the Facebook profiles of various cousins, and I noticed something about Facebook’s photo support that I somehow missed before: it automatically detects the presence of faces in each photo, and allows users to tag each face with the identity of its owner. Already-tagged faces have the owner’s name superimposed over the image.

That’s an awesome feature, and reminds me of the stuff Riya was working on a few years back (although FB doesn’t do facial recognition (yet, anyway), so you still have to tag everyone yourself). I was immediately jealous that my photo hosting software of choice, Gallery, didn’t have this feature.

I investigated this a bit, and I found that Intel’s OpenCV library includes open-source face detection code. Using Intel’s sample face detect app, I found it to be both quick (~150ms per photo) and accurate. I wonder how much work would be required to create a Gallery module that used opencv to detect faces in photos, and provided an AJAX UI for tagging the photos. It would certainly be cool.