2D-to-3D Conversion Chips a Commercial Necessity, Samsung Says

Building 2D-to-3D conversion into 3D TVs may be controversial, but it’s a commercially needed hedge against the lack of available 3D content, a Samsung engineer told us in the company’s European labs Tuesday near Yately, Hampshire, in the U.K.

"Things are moving so fast that our management felt we had to put 3D TVs on the market this year,” said the engineer, David Jung, quality assurance manager at the Yately labs. “When we first launched in the U.S. in March there was only one Blu-ray 3D title, Monsters vs Aliens. There is still very little. How could we deliver the goal of a 3D picture when there is so little 3D content? So we offer the chance to convert 2D material to 3D. It is purely to give the 3D experience to people who buy a set when there is no 3D software for use with it. If and when there is a huge amount of 3D content available, we may not put in the conversion function.” How well 2D-to-3D conversion chips work “depends on the source material,” Jung said. Converting from 2D high-resolution HD material with a high pixel count, “the 3D effect is almost perfect, as long as there are bright images and movement,” he said.

Bryan Burns, ESPN vice president of strategic business planning, has been sharply critical of TV makers that build conversion chips into their sets, fearing they might soil 3D TV’s reputation if consumers see a bad rendering (CED March 3 p1). Burns, whose network launches ESPN 3D on June 11, doesn’t necessarily buy Jung’s rationale, he told us in an interview Thursday. Told of Jung’s remarks, Burns said: “My only reaction to that would be I'm not sure how much consumers who walk into a retail store will ever have the access to understand what the gentleman said or the knowledge to understand what he said. This is about consumers walking in, making a decision at retail, and making a decision in their homes.” Image quality using 2D-to-3D conversion chips “could be a real mixed bag for a long period of time,” Burns said. The ESPN brand “is all about quality, and we don’t want consumers to get turned off about this technology if the quality is not there and not understand why."

Samsung started work on 3D panels and chipsets in 2006, Jung said. In 2010, Samsung is rolling out 17 models, including some LED-edge-lit LCD TVs and some plasma sets, all ranging in size from 40 to 60 inches. All use a single system-on-a-chip that integrates all the 3D functions, including 2D-to-3D conversion on the fly. Less controversially, the same chip that does 2D-to-3D conversion also converts 3D material to 2D, if, for example, there are not enough glasses for the whole family.

Samsung’s technical briefing notes on 3D conversion offer only a broad-brush description of the technology. “Typical 3D conversion,” explains Samsung’s technical document, is by “vertical location.” The image is sliced into half a dozen horizontal zones and the zone at the bottom of the screen -- which is usually the foreground -- is made to come forward, the document says. “But we did not like some of the effects,” admitted Jung, illustrating the point by imitating a man slumped backward in a chair with his feet forward.

Samsung’s proprietary “object based depth processing” uses “depth separation” and “disparity optimization” to suggeest separate left and right eye images, its technical document says. Samsung’s technical description is very sketchy on what this means, only showing a 2D image broken into a mosaic of squares for unexplained processing that separates a walker from trees. However, our search of 3D conversion patents filed by Samsung and others (CED May 27 p4) revealed that a flat 2D image is first analyzed to isolate prominent objects like people, animals, buildings, furniture and vehicles. A computer then scans for depth clues, such as relative size and motion, or focus, of the isolated objects. The flat image is then cloned to produce two identical frames, one of which is left untouched to create an image for viewer’s left eye, and the other right eye image modified under control of the depth clues by moving objects slightly sideways to create an illusion of depth when seen through glasses.

Samsung TVs offer adjustment by remote control of the conversion effect, with 10 levels of created depth. The sets ship from the factory with a default level of 5, Jung said. “We create the depth behind the screen rather than in front,” said Jung, as he provided a demonstration of converting 2D to 3D from live TV. This showed, as expected, a mild depth effect at the minimum setting 1, and an exaggerated and fatiguing effect at 10, with the foreground at the lower part of the screen pushing forward unnaturally from a blurry background. There was, also as expected, less depth when there was less motion. Interestingly, a live HD TV program of several chefs cooking in a studio showed good depth because the camera was continually panning and tracking around the work tops.

Jung thinks Sony, which calls its system “3D Up-Conversion,” will deliver “something similar to ours,” he said. “In the U.S. and Korea, there is a lot more HDTV than in Europe, where most broadcasts are still in SD. And conversion works better with HD. So much depends on the resolution and whether or not the foreground is blurred. That’s why feedback from editors in the U.S. and Europe has been different. You get very good conversion performance from a Blu-ray player. With normal DVD or digital TV, there is not a big improvement.”

By chance, an attempt at comparing the true 3D effect from the Blu-ray 3D of Monsters vs Aliens, played simultaneously from two Blu-ray 3D players through Panasonic and Samsung 3D TVs, revealed a practical issue that could create a new kind of headache for the trade. The infrared sync signals from the two TVs so seriously interfered with each other that it proved impossible to keep both sets running at the same time and change glasses to compare the 3D effect on the two sets. In particular the Panasonic IR swamped the Samsung glasses so badly that one set needed to be switched off for the other to show 3D. It suggested to us that dealers hoping to compare rival brands in the store will need to keep them physically well spaced apart.

We also noted that the Samsung 3D TV unexpectedly gave us a 3D effect when viewed through Panasonic glasses, albeit with curious holes in the picture. Although the holing effect is bad enough to prevent viewers from using the wrong brand of glasses, that the pictures appeared in 3D at all suggested it might not be too difficult for a third party manufacturer to make interoperable glasses that work with the two brands of TVs.

Samsung says its active-shutter glasses have a working battery life of 50 hours, with a manual “on” button. They automatically switch off after a few seconds when the infrared 3D transmitter in the TV is switched off. An alternative version of glasses, rechargeable through USB, gives 24 hours 3D viewing per charge, Samsung says.

Asked about recent Samsung Australia warnings that pregnant women and others not in peak health should avoid 3D viewing, Jung said both Samsung and LG issued health warnings, and “had to. There is no certain information and no research. If we don’t know, we can’t say what’s safe. So it was necessary to make a health announcement, in case of legal action. But it was a very difficult decision.”