With the new Faces functionality in iPhoto ‘09 it is easy to tag and identify “who” is in each of your photos.  With a Smart Album, it’s easy to recall photos that contain 1 or more people in them.

Once you have face tagged a portion of your photos, create a Smart Album.  In the Smart Album choose the Name field. For the condition field choose is.  You can now specify the name of a person from your Faces data.  Next, click on the Plus sign to add another line item, again choosing Name and entering the name of another person.  Make sure before you save that the Match condition is set to all.  This will make sure that this search contains both people you listed.

Here’s a sample of the smart album:

Click OK and you’ll have a smart album that will show you all the photos that contain those 2 people in them.

You can of course add more people if you wish.

TIP: A shortcut to creating the smart album is to just go to your Faces screen, select all the people you want included in the search from the cork board by CMD + clicking them, then simply drag the people to the iPhoto sidebar.  This will create the Smart Album for you.  However, by default this sets the album to the any Match, which means it will find all photos that contain any of the people.  Simply right click on the Smart Album and choose Edit, and change the any to all in the Match field.

Some people have been noting that the initial scan of their iPhoto library for faces has either failed, or has not identified any possible faces.  It seems that Apple has not given a way for users to easily rebuild the faces data.  However, if you want to force iPhoto to rescan your library to identify faces you can do the following:

DISCLAIMER:  This is only for users comfortable with navigating into their iPhoto Library.  Make sure you have a backup of your iPhoto Library before doing anything.  This is not official documentation from Apple.

This procedure will erase any Faces tagging that you have done.

1. Close iPhoto
2. Go into your iPhoto Library in the Finder by selecting iPhoto Library, right click and choose Show Package Contents
3. Delete the file face_blob.db
   
4. Delete the file face.db
5. Restart iPhoto

iPhoto should now start the initial Faces scan again, and it will rebuild anything thumbnails it may have previously created.

Here’s hoping someone finds a hidden terminal preference command to do this, or that Apple adds this ability into the UI.

Apple released iLife ‘09 this week which includes the updated iPhoto ‘09.  iPhoto has a new feature called Faces, which is a face recognition technology that identifies faces in your photos and allows you to assign a name to each face.  This allows you to sort and view photos based on a person or group of people…..very handy.

After you install iLife ‘09 and start iPhoto ‘09 for the first time, iPhoto will scan all your photos and identify what part of each photo may be a face.  This process can be lenghy, so be patient.

After poking around, here’s what I have found so far as to what iPhoto is doing.

iPhoto scans the library the first time it opens, and creates 2 faces .db files within the iPhoto Library:

face_blob.db
face.db

iPhoto creates Faces thumbnails files and places them in the iPhoto Library/Data folder along with the other thumbnails it creates.

For example, I have:

DSC_0202_face0.jpg
DSC_0202_face1.jpg
DSC_0202.jpg

So the DSC_0202.jpg is the thumbnail image that iPhoto had already created when the photo was first added, and the initial face scan added the other 2 images because it recognized 2 faces in that image.

If anyone finds out any other technical data on how faces works, please feel free to drop a comment and I’ll update the post.

Watch out Time Machine users who have upgraded to iPhoto ‘09.  Seems that if you let iPhoto manage your library (meaning you have iPhoto copy all your photos into the default ~/Pictures/iPhoto Library), after the upgrade Time Machine will backup your entire photo library again.  All of it….photos and data files.

I suspect this is due to the fact that Apple is doing special things with the iPhoto Library package.  Because you can browse your Time Machine backups from within iPhoto itself (you don’t need to browse through Finder), Apple probably wanted to get a good full backup of the entire library.

For me it was a 40GB backup that I didn’t want.  So I just went into the Time Machine interface, deleted all backups of iPhoto Libraries, and then let iPhoto backup the new upgraded library again.  This of course means that if you wanted to go back in time to say 3 months ago and get a photo you deleted, that you probably couldn’t, but I was ok with that.

If your library isn’t that large, then I wouldn’t worry about the extra space being taken up on your Time Machine drive.