New technique creates 3D images through a single lens

End of 3D glasses? Researchers have developed a novel new way to create 3D images through a single lens, without moving the camera. The technology developed by the Harvard School of Engineering and Applied Sciences suggests an alternative way to create 3D movies for the big screen. It could also allow amateur photographers and microscopists to create the impression of a stereo image without using expensive hardware, researchers said.

The improbable-sounding technology relies only on computation and mathematics - no unusual hardware or fancy lenses. The effect is the equivalent of seeing a stereo image with one eye closed, researchers said.

Offering a workaround, principal investigator Kenneth B Crozier and graduate student Antony Orth essentially compute how the image would look if it were taken from a different angle. To do this, they rely on the clues encoded within the rays of light entering the camera. The key, they found, is to infer the angle of the light at each pixel, rather than directly measuring it (which standard image sensors and film would not be able to do).

The team's solution is to take two images from the same camera position but focused at different depths. The slight differences between these two images provide enough information for a computer to mathematically create a brand-new image as if the camera had been moved to one side.

By stitching these two images together into an animation, Crozier and Orth provide a way for amateur photographers and microscopists alike to create the impression of a stereo image without the need for expensive hardware.They are calling their computational method "light-field moment imaging".

Importantly, the technique offers a new and very accessible way to create 3D images of translucent materials, such as biological tissues. The new technique makes no allowance for overlapping materials, such as a nucleus that might be visible through a cell membrane, or a sheet of tissue that's folded over on itself."Using light-field moment imaging, though, we're creating the perspective-shifted images that you'd fundamentally need to make that work—and just from a regular camera," Orth said.

"So maybe one day this will be a way to just use all of the existing cinematography hardware, and get rid of the glasses. With the right screen, you could play that back to the audience, and they could move their heads and feel like they're actually there," said Orth. The study was published in the journal Optics Letters.