Display Week 2010 Review: 3-D
3-D displays go mainstream.
by Alfred Poor
ONE MAJOR REASON to attend Display Week year after year is to see the new technologies as they develop. Some come and go, but some eventually make it to the retail market. This is the year that 3-D displays have really cleared that hurdle and are finding their way into retail channels at last. This does not mean that we are finished with the development of 3-D displays; to the contrary, we've only just begun.
3-D was in evidence throughout Display Week, with many different approaches on the show floor, seven of the 77 technical paper sessions, and a full evening of 3-D cinema demonstrations. Tracking the state of the art and what will likely come next was a full-time occupation at Display Week 2010.
Here and Now
SID drove a stake in the ground, marking the advent of the 3-D television age, with its choice for the Gold Winner of the SID Display of the Year Award. LG's 47-in. LCD panel is 3-D ready, and unlike many designs that rely on active shutter glasses, it works with passive polarized glasses similar to those often used in movie theaters. (The passive polarized glasses do not rely on batteries.) A patterned retarder on the display alternates the polarization of each line in the display, creating a half-resolution image for each eye all the time.
The winner of the Silver Award for Display Component of the Year was RealD for its XL Cinema System, which mounts externally to an existing digital projector. This eliminates the need for a second projector or complex alignment and is a system that can be quickly and easily changed back and forth between 2-D and 3-D modes. It provides frame-sequenced alternate polarization for the left- and right-eye images, and audience members can use passive polarized glasses to see the stereoscopic images.
While its booth was small, Panasonic showed off some of its products that are ready to deliver stereoscopic images for consumers. From a professional dual-lens video camera (vaguely reminiscent of the main character in Wall-E) to large plasma screens ready for 3-D images, Panasonic clearly has invested in creating a stereoscopic ecosystem for consumer entertainment (Fig. 1).
Fig. 1: The Panasonic professional 3-D camera can capture stereoscopic images in real time; see the double image of this article's author as he took this photo. Photo courtesy Alfred Poor.
The IMS Market Focus Conference TV 3.0 spent most of its first day just on 3-D TV, 3-D cinema, and related topics. From panels and components to content delivery, the presenters provided a deep and wide look at the 3-D markets.
Can You Believe Your Eyes?
One of the hot topics about stereoscopic displays is whether or not there is sufficient content available to justify their purchase by consumers. (For more on this topic, see this month's Display Marketplace article, "Broadcast and Production Embrace 3-D.") One school of thought states that nothing less than content captured in native 3-D is worth watching (and even then there are many pitfalls to be avoided that could ruin the shoot). Others concede that when performed carefully by experts, it is possible to extract depth information from 2-D original content and obtain results that are worth watching. Still others contend that real-time conversion of 2-D to 3-D content may not be as good as native 3-D content, but is adequate for most viewers.
Those who attended the special Display Week 3-D Cinema Event on Tuesday evening had the opportunity to judge stereoscopic content quality for themselves as dozens of short films and trailers were displayed on a 30-ft. silver screen. The images were shown using an NEC three-chip DLP digital cinema projector with a RealD XL stereoscopic system. Clips included commercials, movie trailers, animated sequences, and converted 2-D content. There was even a short clip from the 1947 Russian film Robinzon Kruzothat was converted to modern 3-D image files.
This content was presented without commentary, other than that the selections were chosen to represent a cross-section. As a result, some of the pieces were stunning, such as certain car commercials in which the depth effects greatly enhanced the experience of view-ing beautiful designs. In other cases, however, some of us gasped and took our glasses off as quickly as possible when the depth data was poorly rendered. This happened most frequently in title sequences where the text and graphics were presented as an overlay in front of a live-action background. The conflict between visual cues was painfully disruptive. And "negative Z" effects, in which objects appeared to be between the viewer and the screen, were the ones most likely to offend one's viewing systems.
Autostereoscopic
One limitation of stereoscopic images is that they typically only have two images: one for the left eye and one for the right eye. This is sufficient for creating the impression of depth in the combined image, but it does not let you see motion parallax in the image. In other words, you cannot move your head to "look around" an object in the foreground to see what is behind it. A new photo frame shown by Newsight Japan solves this problem with some clever processing. It can start with either a native stereoscopic image or just a 2-D digital photo. It then synthetically creates five different views of the scene and displays it on the special autostereoscopic panel (Fig. 2). It really works best for a single viewer, for whom the effect is surprising. By moving your head from side to side, you can see what is behind objects in the image. For now, the processing is done on a PC, but the next version is slated to do real-time conversion using on-board processing.
Fig. 2: The autostereoscopic photo frame by Newsight Japan creates five views of a scene so that you can "see around" objects in the foreground. Photo courtesy Alfred Poor.
Both LG and Samsung showed a variety of stereoscopic and autostereoscopic displays. LG stole the show with its 84-in. UHD LCD television, having the resolution of four 42-in. 1080p sets combined. Fraunhofer HHI demonstrated the Free2C, a single-viewer autostereoscopic system that uses head tracking to steer the images toward the user's eyes. It relies on a fast real-time subpixel sorter with a parallax barrier to adjust the image.
Both Toshiba and 3M showed an improved autostereoscopic single-viewer mobile display. Based on the same technology that the companies demonstrated last year, this frame-sequential system relies on a pair of LED edge lights with an OCB-LCD panel. When the left light is on, the right-eye image is displayed, and a special film directs the light just to the right eye. Then the left light turns off and the right light turns on, and the left image is directed just to the left eye. The "sweet spot" for the stereoscopic effect is rather large, making it easy to use. However, if you get too far off to one side or the other, the effect fails gracefully; you simply see just one image at a lower brightness. The film that makes this possible is just 0.1-mm thick.
None of the autostereoscopic demonstrations indicated that these will be viable options for anything but single-viewer displays any time in the near future. Even the complex head-tracking system was limited to a single viewer. Based on what was exhibited, multi-viewer autostereoscopic displays are still a long way off.
So with a little old news, a bunch of current news, and a whole lot of just-over-the-horizon news, it is clear that the stereoscopic 3-D industry has been well-launched and thriving, and the autostereoscopic industry is still developing. The displays on exhibit provided reinforcement for the position that mainstream 3-D displays for multiple viewers – especially at home – are likely to require either active or passive glasses for many years to come. So, 3-D is now an established part of the commercial display landscape, but we are still looking forward to Display Week 2011 to find out how it will develop next. •
Alfred Poor is an editor and publisher of the HDTV Almanac
and a freelance writer covering technology topics with special emphasis on displays. He can be reached at apoor@ verizon.net.