
How was Google able to suddenly add this massive amount of new data to Google Maps? According to the announcement, the company is using aerial imagery and computer vision techniques to determine the shapes and heights of these buildings. “This process,” says Google, “enables us to provide more building footprints and a more comprehensive and detailed map than ever before.” The same aerial photography Google uses to render these footprints is, of course, also the basis of Google’s 3D maps and it’s probably no surprise that all of the cities Google is highlighting in this release are also included in its 3D maps.
Despite the fact that most of these shapes were created algorithmically, Google also continues to give its users the option to submit corrections through Google Map Maker.