In January 2012 NYPL Labs, the digital library development division of the New York Public Library, introduced the Stereogranimator, a website and collaborative program to turn digital copies of analog stereographic photograph pairs into shareable 3D web formats.
"Stereographs, produced by the millions between the 1850s and the 1930s, were a wildly popular form of entertainment, giving viewers a taste of the kind of richly rounded images now readily available on screens of all sizes. No motion was involved, however. Instead, viewers looked through a stereoscope at two slightly different photographs of the same scene, which the brain was tricked into perceiving as a single three-dimensional image.
"The Stereogranimator . . . uses GIF animation to create the illusion of three-dimensionality by flickering back and forth between the two images. Users can adjust the speed, as well as the spatial jump between the images. The tool also generates an old-fashioned anaglyph, one of those blurry, two-toned images that snap into rounded focus when viewed through a stereoscope or vintage blue-red 3-D glasses. . . ." (http://artsbeat.blogs.nytimes.com/2012/01/26/3-d-it-yourself-thanks-to-new-library-site/, accessed 11-02-2013).
The Stereogranimator grew out of a project originated by writer / photographer Joshua Heineman, who in 2008 observed that
"The parallax effect of minor changes between the two perspectives created a sustained sense of dimension that approximated the effect of stereo viewing. When I realized how the effect was working, I set about discovering if I could capture the same illusion by layering both sides of an old stereograph in Photoshop & displaying the result as an animated gif. The effect was more jarring than through a stereoscope but no less magic" (http://stereo.nypl.org/about, accessed 11-02-2013).