PORTLAND, Ore.—A new algorithm for rendering higher resolution 3-D images was recently described by the Massachusetts Institute of Technology (MIT) Media Lab. The high-resolution 3-D technique is glasses-free, but does not reduce brightness or restrict viewer orientation as with conventional auto-stereoscopic techniques, according to its inventors.
Prototyped by professor Ramesh Raskar’s Camera Culture group, the technique performs calculations for both vertical and horizontal parallax on every pixel in separate left and right images from a stereo camera. Then, instead of converting the images into vertical slits that route the original images to the correct eye with a parallax barrier, the new technique uses a customized multi-perspective parallax barrier that adapts to the amount of 3-D information present at each pixel.
MIT's prototype uses two stacked liquid crystal displays with a parallax barrier that is calculated separately for each image, resulting in an auto-stereoscopic image that is brighter—since it does not half the light from each pixel as with conventional glasses-free displays—plus can be properly perceived even if the viewers head tilts from side-to-side.
Because the parallax barrier blocks less light, the display itself also consumes less energy than conventional glass-free 3-D methods. However the computational complexity of creating a custom parallax barrier for each image will require extra power.
To remedy, the researchers are currently working to simplify the algorithm's complexity, as well as create custom acceleration chips that offset the extra computational effort expended to create the customized parallax barriers that enable the higher resolution 3-D display. Details are available on the MIT Camera Culture website.
Camera Culture members include professor Ramesh Raskar and Doug Lanman, post-doctoral researcher Yun Hee Kim and doctoral candicate Matthew Hirsch.
Instead of using the unedited left and right images from a twin-lens camera, MIT's dual-stacked LCD displays uses content-adaptive parallax barriers as displayed here.
Auto-stereoscopic technology has been around for decades, but only recently have scientists been reexamining its basic principles to fit today's more advanced technologies. MIT's algorithm is just one example of forward thinking that will eventually make 3-D a standard capability for more displays.
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