"Backward-compatible" tech lets video be watched in 2D and 3D simultaneously
By Ben Coxworth
July 19, 2012
According to just about every consumer electronics manufacturer on the planet, 3D TV is on its way to becoming mainstream – perhaps ultimately even ending up as the norm. That’s not good news for people who experience headaches or motion sickness when watching 3D video, or who simply don’t want to put on a pair of glasses every time they watch TV. Help may be on the way, however ... researchers have now devised a system known as “Backward-compatible Stereo 3D.” It allows some people to put on glasses and watch 3D video in its intended three-dimensional format, while others can watch that same video at the same time, in distortion-free 2D.
The system was developed by researchers from Germany’s Max Planck Institute for Informatics, the Computer Science department at Saarland University (also in Germany) and Telecom ParisTech in France. It is based around a new understanding of the way in which our visual system reacts to stereoscopic 3D video images, and how that relates to our perception of the depth of actual real-world objects.
With ordinary 3D systems, two overlapping images of the subject are displayed at once. When viewed through 3D glasses, one of those images is seen by one eye, while the other image is seen by the other eye. This simulates the phenomenon of binocular disparity, in which the brain analyzes the images of an object received by each of our eyes, and determines how far away that object is based on the differences in viewing angle between those two images. The closer the object is to us, the greater the difference between angles, and vice-versa.
One of the things that the scientists looked into was the way in which our visual system combines binocular disparity with other depth cues, such as the qualities of objects’ shadows. This led them to be able to predict what depth objects in 3D footage will appear to be at, via manipulation of these cues.
While the exact workings of the system are confidential, it does reportedly utilize the Cornsweet illusion, in which a gradated central line within an image creates the illusion that the two halves of the background behind it are of different brightnesses, when they’re in fact the same.
What it all boils down to is that when viewed without glasses, Backward-compatible Stereo 3D footage looks pretty much like normal 2D video. In the examples provided, there is still a little fuzziness around the edges of the subjects, although that could perhaps be finessed out with further refinements of the technology.
The system has just been licensed to Canada’s TandemLaunch Technologies, which is developing it for commercial use.
Source: Max Planck Institute