The prior two versions of Microsoft Photosynth, which offer the original synths and stitched panoramas, are still available on the main Photosynth website.
Meanwhile, the updated technology now supports four basic experiences: “spin,” “panorama,” “walk” and “wall” - see Synth types bellow. As their respective names describe, each offers a different kind of 3D image viewing experience – a spin around an object as small as a teacup or as large as a glacial peak, Microsoft explains, a panoramic view, a walk – like down a path through the woods, for example – or a slide across a scene.
Synth TypesPhotosynth : spin
Spin around an object as small as a seashell or as large as a mountain.
Put yourself in the center of a space and look in every direction.
Follow a path through the woods or fly toward a destination.
Slide across a scene, checking out every last detail.
In order to create one of these four different synth types, users upload a set of photos to Microsoft’s cloud service then the technology begins to looking for points (“features”) in the successive photos that appear to the be same object. It then determines where each photo was taken from, where in 3D space each of these objects were, and how the camera was oriented. Next, it generates the 3D shapes on a per-photo basis. And finally, the technology calculates a smooth path – like a Steadicam – through the locations for each photo, and then slices the images into multi-resolution pyramids for efficiency.
The end result is an immersive, and smoother 3D photo experience which gives you more of the feeling of really seeing what the camera had captured. You can actually fly through the scene – it’s almost like a movie. There’s even a play and pause button. You can also share the Photosynth images to Facebook or Twitter, or embed them.
For end users, there’s an expert shooting guide available to help them learn how to make better synths.
How Does It Work?When you upload a set of photos to our cloud service, our technology starts by looking for points (called "features") in successive photos that appear to be the same object.
If it finds many features that reoccur in your set of photos, it passes this information on to the second step: bundle adjustment. Bundle adjustment, a standard technique in photogrammetry, determines where in 3D space each feature is, exactly where each photo was taken from, and how the camera was oriented for each photo.
Third, the technology uses the feature points in each photo to generate 3D shapes. It does so on a per-photo basis rather than trying to generate a global 3D model for the scene. The 3D model generated by Photosynth is coarse—you can see it if you type "c" (for camera) in the viewer and then use your mouse wheel to zoom out.
Next, the technology calculates a smooth path (think of it as a Steadicam) through—or very close to—the camera locations for each photo. Using this path, Photosynth presents the experience of moving through a synth as a gliding motion even if the actual photos were shot at different heights or slightly off-angle. You can see the path if you type "m" (for map) in the viewer. Finally, Photosynth slices and dices the images into multi-resolution pyramids for efficient access.
You need Silverlight plugin to view/edit Photosynth images.
Open source alternative for panorama photo stitching and HDR merging: http://hugin.sourceforge.net/