Posted by admin | 3D Tech,Broadcasting | Monday 2 August 2010 13:25

3D Broadcasting Worldwide Technology

The broadcast signal input interface in television sets is actually settling on side-by-side technologyNote 1) (Fig. 2). Different manufacturers have adopted different approaches to displaying the 3D imagery, such as frame sequential (FS) or Xpol, but the input interface is fairly independent of the display technology. Panasonic and Sony say their 3D sets can handle 3D broadcasting and video distribution from BS11, Jupiter Telecommunications Co., Ltd. (J:COM) of Japan and SKY Perfect JSAT Holdings Inc. of Japan. BS11’s Endo adds “We are still verifying interoperability of sets from various manufacturers, but there aren’t any problems so far.”

Note 1) 3D TVs from Panasonic and Sony support side-by-side, High-Definition Multimedia Interface (HDMI) 1.4, and top-and-bottom, which inserts each images for left and right eye at the top and bottom of each frame.

Fig. 2 3D Imagery Display Method Independent of Broadcast/Transfer Data Format
Diagram shows content flow for display of 3D imagery on a 3D set. The multiplexing technology for the left and right images, broadcast encoding technology, and 3D image display technology are largely independent of each other.

†Frame sequential (FS) method: One method of displaying 3D imagery. The frame of the images for left and right eye are displayed alternately over time, synched to LCD shutter glasses for viewing.

†Xpol method: Another method of displaying 3D imagery. Polarizing film is affixed over the panel, and the polarization direction alternated for each horizontal row of pixels. The left and right images are displayed line-by-line.

Most 3D image broadcasting systems have adopted side-by-side because it ensures frame compatibility with existing broadcast technology (Fig. 3). In side-by-side, two images for left and right eye captured with the 3D camera are compressed into two frames, and broadcast as a single video frame. The television splits out the left and right images from the received frame, decompresses each to 2x and displays the result.

†Frame compatibility: A video frame using the new broadcasting method is still compatible with existing broadcast video frames, which means that the relay systems will not have to be changed when the broadcasting scheme is.

Broadcasting Technology: Interoperability or Resolution?
The side-by-side solution retains frame compatibility with existing 2D broadcasting, but horizontal resolution is roughly halved. MVC, on the other hand, offers high-resolution frames incompatible with existing schemes, making it impossible to use in general MPEG-2 based broadcasting.