Douglas Lanman, Matthew Hirsch, Yunhee Kim, and Ramesh Raskar. Proceedings of SIGGRAPH Asia 2010
MIT Media Lab
We have developed a 3D display that eliminates the need for special glasses. Until now, the commercial potential of glasses-free 3D displays, particularly those based on liquid crystal displays (LCDs), has been primarily limited by decreased image resolution and brightness compared to systems employing special eyewear.
We have found a way to increase the brightness and resolution of LCD-based, glasses-free 3D displays using a method they call Content-Adaptive Parallax Barriers. Current commercially-available, LCD-based 3D displays are based on a simple concept, first proposed by Frederic Ives in 1903; Ives achieved the illusion of depth by introducing the notion of a parallax barrier. In his design an array of slits is placed slightly in front of a normal 2D display. The slits ensure that each eye sees different regions of the underlying display and, therefore, different images. This method is still widely-employed today, despite its limitations. In particular, the slits required by Ives's parallax barriers function by blocking rays of light and, as a result, significantly reduce the resolution and brightness of the underlying display.
Content-adaptive parallax barriers improve upon Ives's method by allowing the spacing and orientation of slits to be optimized to transmit as much light as possible, while retaining the fidelity of the projected 3D images. The key insight is to realize that the pattern of slits must be changed depending on the 3D scene being projected. By eliminating the prior fixed, heuristic design, content-adaptive parallax barriers can significantly increase the brightness of glasses-free 3D displays based on LCD technology. Furthermore, by using recent high-speed LCDs, the researchers have shown that full-resolution 3D images can be achieved. Content-adaptive parallax barriers are well-suited to mobile devices, optimizing the brightness of displays without reducing battery life.