A computational method called light-field moment imaging creates 3-D images using a single, stationary lens, a discovery that could have implications for medical imaging and even future 3-D displays. Principal investigator Kenneth B. Crozier, an associate professor at the Harvard School of Engineering and Applied Sciences (SEAS), and graduate student Antony Orth discovered that by taking two images from the same camera position and focusing them at different depths, a 3-D image can be stitched together. The slight differences between the two images can provide enough information for a computer to mathematically create a new image, as if the camera had been moved to one side. Research by Antony Orth and Kenneth Crozier (at left) enables photographers and microscopists to quickly create 3-D images without special equipment. Photo by Eliza Grinnell courtesy of Harvard SEAS. The investigators relied upon clues hidden within the rays of light entering the camera to develop a computational method called light-field moment imaging. Instead of directly measuring the angle of light at each pixel, they simply infer it. This technique provides new ways of creating 3-D images of translucent materials, such as biological tissues. “This method devised by Orth and Crozier is an elegant solution to extract depth information with only a minimum of information from a sample,” said assistant professor Conor L. Evans of Harvard Medical School, a bioimaging expert who was not involved in the research. “Depth measurements in microscopy are usually made by taking many sequential images over a range of depths; the ability to glean depth information from only two images has the potential to accelerate the acquisition of digital microscopy data.” Courtesy of Antony Orth. The discovery could also have applications in the film industry; the perspective-shifted images needed to make 3-D movies may now be created with a regular camera. “So maybe one day this will be a way to just use all of the existing cinematography hardware, and get rid of the glasses,” Orth said. “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.” The work was published in Optics Letters. For more information, visit: www.seas.harvard.edu