I don’t really use iPhoto. Its casual-user focus makes it poorly suited to what I want in a photo-management app, and it’s not particularly useful as a general-purpose image catalog tool, either.

There’s some interesting technology in it, however, including Faces, which attempts to detect and recognize human faces in photos, allowing you to (potentially) organize your pictures by who’s in them. It’s not integrated into the app very well yet, and there are some odd bugs, but it turns out to be surprisingly accurate and useful.

Since I was home sick yesterday and not up to much else, I imported a collection of 1,421 scanned photos of attractive young women and told it to look for faces. On the first pass, it found faces in about 80% of the pictures, and only a few of those were false positives (jewelry, plaids, etc). A second recognition pass got it up above 90%, out of a total of 95% that really did have at least one human face. Most of its failures involved faces that were tilted at roughly 45 degree angles, as well as profiles and low-contrast images. It did surprisingly well at finding low-resolution faces, and even did a fair job of auto-naming them correctly, once I had a good sample size.

[Bug note: There are a few images that I simply cannot manually add a face to, and I don’t know why. I draw out the rectangle, add a name, hit Done, and it deletes my work. It thinks there’s something there, because it will offer them as options in the “person X might be in this picture” section, but it never accepts the face.]

It takes a little while to figure out a decent workflow for adding names to pictures, but it does work. If you select a few good matches for each major face, the name-guesser will perform a lot better, and save you a lot of manual selection. I’d like to see it offer the top three choices instead of just the best one, and the UI needs some work (especially in keyboard navigation consistency and false-positive handling), but it works, and in normal usage, most people won’t be tagging a thousand images at once.

As far as integration goes, the names you tag a picture with aren’t keywords, don’t show up in the Get Info page, can’t be searched via Spotlight, can’t be displayed or printed as captions, can’t be used to sort, etc, etc. There’s a Faces-specific browser, and you can click the Names button on a full-sized image to view all the tagged Faces present, but that’s it. It’s not useful as a general “person X is in photo Y” tagging system yet.

[Update: I was just reminded of another missing feature that I really want: a “faceless” rule for Smart Albums, so I can say “all pictures from Album X that have no faces in them”. After 80% of the 1400+ images in my album had names, I only wanted to sort through the ones that didn’t, and the only way I could find to do it was to create a smart album Y as “pictures from Album X that have faces, none of which are unnamed”, manually copy its contents to another non-smart album Z, then define a new smart album as “pictures from X that aren’t in Z”, and remember to keep Z up to date. (the app won’t let me say “pictures from X that aren’t in Y”)]

Now for the amusing picture. This is what happens when all of the faces you’ve identified come from professionally shot photos of young Japanese women in full makeup:

The correct answer is “none of the above”. I hadn’t manually named any of her pictures yet, so it couldn’t have made the correct guess, Mana Ogawa, but I liked the way it picked a different name for each picture.