Official blog for the Windows Live Digital Memories
We've always had keyword (descriptive) tagging in Photo Gallery. Heck, we've had it in Microsoft photo products since Windows XP. So why add a whole new type of tag to Windows Live Photo Gallery? Because people take lots of pictures of people. Think about the photos that are most special to you. Let me guess— they have people in them, right? So it makes sense for the software you use to organize your photos to help you focus on the people in them. That's what people tags are all about.
In the beta version, you can see that once you sign in to Windows Live, we add your contacts to the navigation tree. When you click a contact, you see all the photos you've tagged of that person, as well as links to photos they're sharing with you.
But your contact list is just a start. Someone doesn't have to be a Messenger or Hotmail contact for you to tag them. You can tag anyone. Just click the Add a new person link, or type in a new name when you're tagging.
If there's a face in your photo, Photo Gallery automatically finds it, which makes tagging people faster and easier. From the gallery view, you can see how many untagged people are in your photos, and follow the link to tag them. Photo Gallery can't find every face, so you can always click Add people tag to add tags yourself.
There are a few ways to add people tags to photos. In gallery mode, you can bulk add by selecting several photos and dragging them to the person you want to tag in the navigation tree. When viewing a single photo, you can apply an individual tag to each found person by clicking the identify link in the info pane. You can also click the face of the person you want to tag.
What's unique thing about the Photo Gallery tagging system is that, like keywords, people tags are written to the file. So if you copy the photo to another computer or back up all your photos, your tags stay with the file. Because the people tags are attached to your photos, the people you share them with will be able to see your people tags. Of course, we also want to make sure you stay in control of your data, so we've added some new settings to let you manage the metadata you publish on photo-sharing sites.
For the developers out there, the people tags are written out as XMP and, yes, you can read them. I expect folks writing publish plug-ins to take advantage of this.
— John Thornton, Program Manager