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1/2011

Archive 02/24/2011
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Science magazine Interface 1/2011
Research

3D TV takes you inside virtual worlds

Atanas Gotchef

The 3D Media Group led by Atanas Gotchev conducts
R&D, for example, into multi-camera recording methods.

"The breakthrough of 3D television is coming, but it'll take a few more years," says Academy Research Fellow Atanas Gotchev, team leader of the 3D Media Team at Tampere University of Technology.

This visual spectacle will be hard to surpass, many viewers said after seeing James Cameron's Avatar that takes 3D to a new level. If leading television manufacturers are anything to go by, we will soon be able to enjoy 3D in our living rooms. The first 3D televisions hit the Finnish market last summer.

"3D is a natural step forward for the television industry, just like colour TV and stereo sound. Households are now starting to make the transformation to high-definition television and then, maybe in five years or so, 3D television will really take off," predicts Atanas Gotchev.

Although prices are still high, consumers already have their eye on 3D televisions.

"It's no wonder, because this technology creates an almost realistic viewing experience. It allows you to immerse yourself in the 3D world."

After the hype cools down, people will no longer crowd to see 3D films out of curiosity. Gotchev, who admits to being a critical viewer, expects filmmakers to invest in quality content in addition to first-rate technology.

"3D technology opens up incredible possibilities but still needs further improvement. And yes, I've watched Avatar. It was very well done, but you can also watch nowadays poor-quality, ‘flat' or ‘hyper-depth' 3D films on the big screen," he says.

From illusion to genuine three-dimensionality

The illusion of three-dimensionality is created by presenting slightly different-perspective images to each eye. The so-called first-generation 3D televisions available in the market achieve this by having the viewer wear shutter or polarized glasses.

Shutter glasses have LCD panels in each eye which black out one eye at a time, so each eye sees a slightly different angle of the same image. The shutters are synchronized via infrared with the refresh rate of the screen, alternating the images displayed to each eye at a rate of 60 frames per second.

Polarized glasses project the same scene into both eyes, but the two images come from differently polarized light sources and the glasses filter the proper image for each eye. Your brain does the rest.

3D Media Team conducts world-class research

  • The 3D Media Team within the Department of Signal Processing at TUT is part of the department's Centre of Excellence appointed by the Academy of Finland.
  • The group develops methods for 3D image capture, processing and display as well as novel signal processing methods for depth extraction.
  • The group's primary research interests are digital holography and the development of advanced imaging for 3D displays. Among others, the group collaborates with Nokia Research Center to develop techniques for real-time multi-camera depth analysis.
  • The group makes extensive use of user experience research methods and is engaged in close collaboration with the Unit of Human-Centered Technology at TUT. Both are involved in the EU's Mobile 3DTV project that aims at developing glasses-free 3D technology for mobile devices.
  • The group's international collaboration partners are, e.g. BIAS from Germany and ETRI from South Korea.

"Next-generation autostereoscopic 3D televisions are viewed without glasses. They're already available but not in the consumer market," says Gotchev.

An autostereoscopic display has an integrated lens system that casts images directionally into the viewer's eyes. This eliminates the need for 3D glasses, but viewers have to look at the display from a certain position called ‘sweet spot'.

"Our 3D Media Team is extensively involved in developing signal processing and measurement technologies for autostereoscopic displays and related user studies."

"Autostereoscopic 3D may be short-lived, since the advent of next-generation light-field 3D television is already on the horizon. It is an advanced version of an autostereoscopic display that still employs a lens system but with much more views thus facilitating the freedom to move around the displayed scene."

Current 3D imaging technology basically tricks the brain into creating the illusion of depth, but it is possible to produce genuine three-dimensional images by using a holographic display. Straight out of science fiction, scientists have already succeeded in creating 3D holographic images that appear to float in midair and can be viewed from all directions in a laboratory environment.

"Holography is a technique that allows the light reflected from an object to be recorded and later reconstructed as an exact replica of the original. It'll require in-depth knowledge of the principles of holography and advanced laser applications before holographic presentation technology becomes a reality," says Gotchev.

 

Text and photo: Päivi Eskelinen