3-D It Yourself, Thanks to New Library Site Four years ago, a San Francisco artist and writer named Joshua Heineman began making animated versions of digitized vintage stereographs from the New York Public Library's collection and posting them on his blog. The project quickly went viral, attracting as many as 70,000 visitors a day to its mesmerizing 3-D animations of old-school cyclists zipping around on penny-farthings and heavy-skirted matrons reclining over a picnic. Now the library itself has done Mr. Heineman's populist raid on the archives one better and created its own Stereogranimator, a graphic tool that allows users to try their hand at bringing the more than 40,000 digitized stereographs from its collection back to flickering life. "It's a nice example of the cool things that can happen when you put library collections online in free, repurposable forms," Ben Vershbow, the manager of NYPL Labs, the unit responsible for the project, said in a telephone interview. Mr. Heineman puts it more vividly in an essay on the project's Web site, writing: "This is my Frankenstein's monster. Now, thanks to the NYPL team, it's your monster too. 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, like Mr. Heineman's original project, 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. The newfangled "RealD" glasses you brought home from last night's showing of "Hugo," alas, won't work. The more "objective" anaglyphs, Mr. Vershbow said, will probably be a bigger draw for scholars and stereoscope nerds. Yes, they exist. But the GIF animations, he insisted, are more than just crowd-pleasing eye candy. Instead, he said, they themselves provide a kind of stereographic historical vision, fusing nostalgia for early 3-D technology with nostalgia for the early days of the Web, when it seemed that every other homespun site featured a cheesy GIF image flashing "New!" or "Under Construction." "These animations were one of the first ways ordinary creators could add a little visual pizzazz to their Web pages," Mr. Vershbow said. They were often used to convey the way the medium for the Web was changing. The Stereogranimator also reflects how the library itself is changing, using digital technology to open its collections to patrons in new ways. NYPL Labs's What's On the Menu? project, for example, started last April, has already enlisted some 65,000 participants to transcribe 730,000 dishes from the more than 40,000 restaurant menus in its collection, generating data that others might use to study price trends, or the rise and fall of sun-dried tomatoes. Mr. Vershbow said he expects a lot of users to retweak the library's tweak of Mr. Heineman's original idea. All the images are in the public domain. And if any the results are interesting enough, they may be archived as part of the library's collection. "The central purpose of the Stereogranimator," he said, "is to make new things out of old things."