Phillips is now producing television sets the reproduce 3D images without the need for viewer glasses. Technology Review reports:
The technology uses image-processing software, plus display hardware that includes sheets of tiny lenses atop LCD screens. The lenses project slightly different images to viewers' left and right eyes, which the brain translates into a perception of depth. For now, the screens are expensive and not yet marketed for home use. But Philips, which first released the technology in 2006, is working on technical improvements that will make the screens better suited for the home. [...]
This isn't the first time that 3-D has made a splash. The early 1950s and early 1980s each saw their own fads. The 3D movies from the 1950s were filmed with two cameras, with the separate images then projected simultaneously. The familiar red-and-blue-lensed glasses were used to trick the eyes into interpreting color differences as distance. Modern 3-D movies employ more-sophisticated approaches, such as projecting the separate images in polarized light and using glasses with polarized lenses that filter out one image on each side.
But a combination of advances in computer image processing and industrial optics has allowed companies like Philips to develop their glasses-free technique.
As with earlier techniques, the illusion requires specially-created content to start with. In this case, a digital movie file effectively has two frames for each ordinary movie frame. The first is an ordinary color image, identical to what would be seen on a two-dimensional screen. A second frame, rather than showing a second offset view, encodes information about how viewers should perceive depth in the first frame. It appears as a grayscale version of the first, with white indicating foreground objects, black denoting deep background, and shades of gray indicating points in between
Then, special PC-based hardware and software--housed in the display itself--processes the pair of images as the video is played. The information in the second frame is used to transform the original color frame into nine separate images, each slightly offset from the last, as though the camera had been moved a few inches to the side each time. All nine are then sent to the screen.
To allow viewers to perceive these images, the LCD screens are overlaid with three-pixel-wide cylindrical lenses that direct the different images into side-by-side paths. A nearby viewer will see one of these images with each eye--the first and third, or third and fifth, for example--thus producing the illusion of image depth.
The multiple images allow viewers to walk around the viewing area--a cone about 20 degrees wide--without disturbing the 3-D illusion, says Philips product manager Erik van der Tol. This cone is duplicated several times on each screen, further widening the 3-D viewing area. [...]
As with any new technology, there are glitches. With the company's 42-inch screens, the 3-D effect works most effectively only up to a distance of about 12 feet, and if you view the screen at the boundary between the three "cones," you experience garbled images. In addition, the quality of ordinary two-dimensional images on the screens is diminished. Finally, a 42-inch screen will set you back $12,000 (prices on the new 52-inch and 22-inch models being released next week have not yet been specified)."
Look for this in the home in a couple of years.
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