3D movies provide viewers with a completely new experience by allowing them to visualize places and objects in ways that are otherwise not possible. However, unattractive 3D glasses are essential to enjoy every 3D experience. Fortunately, a display developed by a group of researchers from MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) and Israel’s Weizmann Institute of Science could enable audiences to watch 3D movies without wearing 3D glasses.
Called “Cinema 3D,” the prototype display enables viewers to watch a 3D film from any seat in a movie theater using a special array of mirrors and lenses.
Existing approaches to glasses-free 3D require screens whose resolution requirements are so enormous that they are completely impractical. This is the first technical approach that allows for glasses-free 3D on a large scale.
Wojciech Matusik, Professor, MIT
While the research group cautions that the system is not yet for ready for commercial use, they are optimistic that future variants could extend the technology to a place where movie theaters could provide glasses-free options for 3D films.
MIT research technician Mike Foshey; former CSAIL postdoc Piotr Didyk; and two Weizmann researchers, including Efrat and professor Anat Levin, are the other co-authors on the paper. The paper will be presented by Efrat at SIGGRAPH computer-graphics conference in Anaheim, California.
Although Glasses-free 3D technology is not a new thing, it is not available in a scale large enough for movie theaters. Conventional techniques for television sets use a series of slits before the screen (a “parallax barrier”), which allow each eye to observe a different set of pixels, generating a simulated sense of depth.
However, parallax barriers need to be at a constant distance from a viewer, this method is not feasible for larger spaces such as movie theaters, where viewers are at different distances and angles. In other approaches, including a method from the MIT Media Lab, completely new physical projectors need to be developed that are capable of covering the complete angular range of the viewers. However, this development often comes at the expense of lower image-resolution.
The principle factor behind Cinema 3D is that viewers in theaters make head movements only over a narrow range of angles, restricted by the width of their seat. It is sufficient to display images to a small range of angles and reproduce that to all seats in the movie theater. Cinema 3D then encodes multiple parallax barriers in one display, allowing each viewer to see a parallax barrier customized to their position. It then replicates that range of views across the movie theater using a series of mirrors and lenses in its special optics system.
With a 3-D TV, you have to account for people moving around to watch from different angles, which means that you have to divide up a limited number of pixels to be projected so that the viewer sees the image from wherever they are. The authors [of Cinema 3D] cleverly exploited the fact that theaters have a unique set-up in which every person sits in a more or less fixed position the whole time.
Gordon Wetzstein, Assistant Professor, Stanford University
The researchers showed that their method allows audience from various places of an auditorium to see consistently high-resolution images.
At the moment, Cinema 3D is practically not feasible: 50 sets of lenses and mirrors are required for the prototype, but it is still only slightly larger than a pad of paper. Theoretically, this technique could function in any context where 3D visuals would be displayed to a large number of people simultaneously, for example, storefront advertisements or billboards. Matusik explains that the researchers hope to develop a larger variant of the display and to refine the optics to further improve the resolution of the images.
It remains to be seen whether the approach is financially feasible enough to scale up to a full-blown theater. But we are optimistic that this is an important next step in developing glasses-free 3-D for large spaces like movie theaters and auditoriums.
Wojciech Matusik, Professor, MIT
The Israel Science Foundation and the European Research Council funded the research work.