Section: Application Domains
Video processing for 3-D displays
Participants : Frédéric Devernay, Sergi Pujades, Elise Mansilla, Martin Guillon.
Until recently, in order to view stereoscopic 3-D video, the user had to wear special glasses. Recent advances in 3-D displays provide true 3-D viewing experience without glasses. These screens use either a micro-lenticular network or a parallax barrier placed in front of a standard LCD, plasma, or LED display, so that different viewpoints provide different images. If the characteristics of the network and the screen are carefully chosen, the user will perceive two different images from the viewpoints of the left and right eyes. Such glasses-free 3-D screens usually display between 8 and a few dozen different viewpoints.
When the 3-D scene which has to be displayed is computer-generated, it is usually not a problem to generate a few dozen viewpoints. But when a real scene has to displayed, one would have to shoot it through the same number of synchronized cameras as there are viewpoints in order to display it properly. This makes 3-D shooting of real scenes for glasses-free 3-D displays mostly unpractical. For this reason, we are developping high-quality view-interpolation techniques, so that the many different viewpoints can be generated from only a few camera positions.
Another problem with 3-D displays is transmission bandwidth. There is much redundant information between the images to be displayed at different viewpoints. Transmitting video streams separately, even if each of these is compressed, would not take advantage of this redundancy. Most video compression techniques only take into account the temporal redundancy of video streams. For 3-D video compression we must also exploit the redundancy between viewpoints. We are approaching this problem using stereo-vision techniques that are currently used for view interpolation.