The tours are now available for more than 15,000 locations, and they include popular tourist spots like Italy’s St. Mark’s Basilica or Yosemite’s Half Dome. The new feature is accessible when a user searches for a place, and then the left-hand panel will display any live photo tours. Just click the thumbnail or link to embark on the photo tour. Indications for photo tours also appear when browsing Google Maps. In this instance, just click a landmark’s label to find an available photo tour.
On the Official Google Lat Long Blog, Google Software Engineer Steve Seitz described the production process of photo tours using advanced computer vision techniques from public images in Picasa and Panoramio:
We start by finding clusters of overlapping photos around major landmarks. From the photos, our system derives the 3D shape of each landmark and computes the location and orientation of each photo. Google Maps then selects a path through the best images, and adds 3D transitions to seamlessly guide you from photo to photo as if you’re literally flying around the landmark and viewing it from different perspectives.