Think of it as a puzzle. Just as in a puzzle, all of the pieces need to be in place to see the entire picture. In this case, the picture we are talking about is 3D TV for the consumer and the puzzle piece is the means of transmitting the 3D image from the 3D source to the viewer. Transmission channels for other 3D applications such as digital cinema and visualization exist, but how do you transmit 3D television to millions of viewers, or hundreds of millions of viewers, without building a parallel 3D-TV broadcast and distribution infrastructure?

Art Berman
Insight Media Consultant

Matt Brennesholtz
Insight Media Analyst

Sensio Technologies of Montreal believes they have a solution to this problem. After discussing the technology with Nicholas Routhier, Sensio’s President and Chief Executive Officer, Insight Media believes that Sensio has a practical, easy to implement solution to the problem.

Any system for the transmission of 3D imagery must be compatible with the extensive infrastructure already in place for video. The entire video industry from content creator through viewer has gone through (or is going through) a massive disruption with the introduction of digital broadcasting and HDTV. No one wants a second disruption for 3D TV. This means that any method proposed for the transmission of 3D video should:

1. Be compatible with normal TV broadcast, satellite and cable transmission channels.
2. Be compatible with existing consumer recording and play-back systems, including DVD, Blu-ray, HD-DVD and DVRs.
3. Provide the high image quality the consumer has become accustomed to in HDTV systems, especially for movies and sports.

The Sensio approach is a variation on the squeeze-frame system that has been around for years. In a simple squeeze frame system, the left and right images are each reduced in resolution by a factor of 2x and placed side-by-side in the normal image area. The simple squeeze frame approach satisfies the first two requirements but not the third. When you unsqueeze the images and show them on a 3D-TV, you have lost half of the horizontal resolution, with a noticeable degradation in image quality. If one were to look at the image on a normal TV, the image would be two images side by side on the screen.

What is new is the fact that the Sensio squeeze frame approach does not reduce the horizontal resolution of the image by half. In the Sensio compression step, the high horizontal spatial frequency information that would normally be discarded is re-inserted into the video signal in place of information that encodes features the consumer would not normally see. To unsqueeze the video, the left and right eye frames are separated, the high horizontal spatial frequency is removed from where it was stored and inserted into the correct horizontal position. Routhier went on to explain that although the unsqueezing process does not perfectly restore the original image, the visual quality of the reconstructed left and right eye images is substantially indistinguishable from the originals.

To prove the point, Routhier reported that Sensio has run side-by-side visual tests. On one TV display the original 1080 video image was shown. On a second, identical TV, the Sensio algorithm was used to squeeze and then unsqueeze the video and one of the images from the stereo pair was shown. While Insight Media has not seen this demo, Routhier says that most viewers cannot tell the difference between the two signal paths. Sensio is expected be an exhibitor at 3D Biz-Ex September 18-19 in Burlingame, CA so we should see a demo there.

Sensio has recently announced it signed a letter of intent with Kerner Optical Research and Development Corporation (KORD). KORD wants to integrate Sensio technology into a new LCD HD television, which is currently the object of a development contract between KORD and LCD television manufacturer SpectronIQ. Sensio and KORD will share the development budgets allocated for the project and the final terms of the agreement will be specified in a contract to be concluded at a later date. According to Sensio, as a result of a recent tour of Asia with their demonstration, six other consumer electronics manufacturers have also expressed a serious interest in Sensio technology, although Routhier declined to name them.

The Sensio approach is not necessarily the perfect approach to 3D transmission standards. One additional requirement must be met by the ideal standard:

   4. Backward compatibility so a consumer with a 3D TV sees 3D and a consumer with a 2D TV sees a normal 2D image.

Sensio does not meet this requirement. Viewing a Sensio 3D image on a 2D TV gives you two rather low quality images side-by-side. Other transmission schemes such as the 2D+depth approach of Philips and the MPEG-style image difference approach of TDVision can meet all four requirements. Nevertheless, the Sensio approach provides a quick path to 3D TV. 2D movies have been released on two versions of the DVD for years: full screen and wide screen. Perhaps 3D will follow a similar path: normal 2D DVDs and Sensio-encoded 3D DVDs released simultaneously.

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