Microsoft's Photosynth stitches pictures into 3D collages

Last night, Microsoft agreed to share one of its favorite web toys. Photosynth, a dazzling application that’s been kicking around Microsoft’s back shop for more than a year, released a public beta version on Wednesday.

The clever code takes flat digital images and sows them into a 3D collage. For example, if I’m selling my condo, Photosynth can take some pictures of the apartment and turn them into a full walk-through tour. It recognizes when objects – a sofa, bookcase, doorway – appear in multiple frames and automatically figures out how to overlap the images to give the greatest sense of depth and accuracy. A prospective buyer could then virtually walk around a room, taking it all in from different perspectives.

For the program to work well, it requires a lot of photos of the same thing from different angles. You need at least three photos of any one object to pull off the 3D effect, but Microsoft project architect Blaise Aguera y Arcas told me a few months ago that Photosynth works best when it can churn through hundreds of images. So, if I were selling my place, I might spend a whole afternoon snapping pictures before my tour is worthwhile.

If you want to see Photosynth in action without the time investment, Microsoft has several impressive examples of museums and major landmarks. (Right now, the program only work on PCs.)

Mr. Aguera y Arcas muses about connecting Photosynth to an image service like Flickr. Then, millions of images taken by thousands of people could be compiled into 3D models of popular tourist destinations. Check out his TED talk, where he shows off Photosynth’s rendering of Notre Dame.