Macworld forum visitor skfx4 faces the daunting job of identifying faces. He writes:
I just upgraded to iPhoto 11 and now have the dubious task of assigning face names to 24,000 faces in my iPhoto library. Does anyone know of any shortcuts to this process?
iPhoto’s magical powers go only so far. But that doesn’t mean that when identifying faces in your images you have to click every single image and name it. It works like this:
After you’ve imported your images, iPhoto will set about identifying faces in your library. It obviously can’t assign names at this point, but it can separate human faces from random patterns on a tortilla. Select Faces in iPhoto’s Library pane and you can watch it work through your images, displaying faces it finds as it goes.
When it’s completed the job, you’ll see a collection of faces on a cork-board background with “Unnamed” appearing beneath each image. Highlight one of these fields and enter the name of the person in the image. Repeat for the other images on the cork-board. If you like, click Show More Faces and you’ll see other faces from your library. Enter their names as well. When you’re ready for serious naming, click Continue to Faces.
This screen will show one picture of each face you’ve identified. Double-click on one of those faces and you’ll see the entire image the face came from. Now, here’s where the shortcut comes into play. At the bottom of the window you’ll see a Bubba May Be in 46 Additional Photos entry (where Bubba is only Bubba if you know and have named a Bubba). Click the Confirm Additional Faces button at the bottom of the window.
This is where the magic happens. iPhoto has made its best guess about which of your images contain Bubba’s mug. At the top of the window is the one image you’ve named and confirmed. Below are unconfirmed faces. Beneath each is a Click to Confirm entry. If you were to click each of 24,000 images, you would set yourself on the short path to insanity. So don’t.
Instead, click and drag across contiguous images of Bubba. When you do so, each image is assigned that name. If iPhoto’s done its job properly (and honestly, it’s pretty good), far more faces will be Bubba’s than another person’s. Alternatively, if nearly all the faces are Bubba's drag across all the images and then just click those that aren't Bubba to reject them. If you've chosen the first method, before clicking Done, be sure to Option-click those faces that don’t belong to Bubba. This helps with iPhoto’s identification as well. If you find an incorrectly named face that you’d like to name, Control (right) click on the image, choose Name from the menu, and enter the correct name. If you’ve already named this person, their name should appear when you’ve typed the first couple of letters.
When you click Done, you’ll return to Bubba’s page where you'll likely see another entry at the bottom indicating that Bubba may be in additional photos. Your first training has helped iPhoto identify subsequent images of Bubba. Click Confirm Additional Faces and repeat the previous process. You may find that you have to do this a few times before you’re no longer prompted to identify Bubba in other images.
Once you’ve finished with Bubba, continue on with other faces. I understand that this sounds like a tedious process, but when you invoke the power of selecting multiple images, the job gets a heck of a lot easier. And it’s not something you need to do in one sitting. In those minutes when your Mac is tied up doing other things—downloading a movie from the iTunes Store or processing iPhoto thumbnails in iMovie—dash over to iPhoto and spend a few minutes identifying faces. A few of these sessions and your work will be done.