3-D movies in your living room may soon be a reality, writes Anthony Fordham, and you won't have to wear goofy glasses, either. Some of our readers may be able to remember the experience of going to the movies as children and seeing Disney's Snow White, or the Wizard of Oz, both films that used an amazing new technology called Technicolor. Now content providers and hardware manufacturers want to give a whole new generation of viewers a similarly paradigm-shifting experience, with 3-D TV.
The real surprise is not that three dimensional, or 3-D TV, is only a few years off, it's that the technology has taken this long to reach us. Indeed, while much of our current technology is more advanced than say the props in Star Trek‚ we still can't enjoy holographic real-time images as seen in every half-baked sci-fi film since about 1950.
First, the good news. Several developers are ready to roll out 3-D TV technology, using commercial installations such as advertising billboards and information displays in shopping centres to jumpstart the 3-D display industry. Then, as always, we'll see the kit filter down into our own lounge rooms.
Four eyes and 3-D
The 3-D TV we're talking about here isn't like the various 3-D theatre experiences you might have had any time between the early 1980s to just last year with the release of Disney's Meet the Robinsons.
In those 3-D films, you need to wear a pair of glasses to create an illusion of depth. The most primitive systems use paper glasses with one red lens and one blue, with colour 'ghosts' on screen that are filtered out alternately by each eye, fooling your brain into thinking there's depth.
More sophisticated systems use flickering LCD glasses, which can cause headaches in some users, or polarised glasses which are the simplest and most effective.
Going to the movies with the kids and getting popcorn and wearing silly glasses for two hours is fun, but who wants to do that all night on the couch?
Researchers such as Philips and the Fraunhofer Institute for Telecommunications, as well as specialist companies like SeeReal, have spent the last decade working to perfect 3-D systems that don't need glasses. You watch them just like a normal TV but, incredibly, the image has depth. It appears three-dimensional.
WoWvx from Philips
Philips is one of the companies closest to a real-world release. With a technology called WOWvx, the company is deploying 3-D flat panels into shopping centres to see how passers-by react. And judging from the dozens of videos the company has proudly posted on YouTube, the response has been good indeed: people seem unable to walk past a 3-D TV.
How does it work?
Brace yourself: it's about to get a bit technical.
Actually making a 3-D image in theory is easy. You simply show a human one image in their left eye and the same image from a slightly different angle in their right eye. The brain automatically combines both images and interpolates them in such a way to create a sensation of depth.
So the only trick is to get those two images into the correct eyes, when beaming light out of a single flat display, without the need to wear special glasses.
The solution is a system called a multiview lenticular lens. Along with a flat panel with LCD pixels arranged in a grid, a 3-D display includes a sheet of lenticules across the very front.
It's a little bit like those novelty pictures where if you turn the picture in one direction it shows one image, but if you tip it in the other you see something completely different.
Another low-tech example is the new energy drink Mother, which is being promoted using a mat with a lenticular sheet on the top to display a static 3-D ad which you might have seen on the counter at a service station. The can of drink appears to 'float' just below the surface of the mat.
It's the lenticular sheet that creates the 3-D effect, because it bends light from the image below to put one view of the image to your left eye, and a slightly different view to the right.
Since this method is so well established, it should come as no surprise that Philips' WOWvx tech uses the same system, albeit on a high resolution display that can show moving images.
As the viewer watches and objects move across the screen, the lenticular sheet scatters the light in different directions, ensuring the left eye sees a different image to the right. The fact the sheet has hundreds of lenticules means there doesn't have to be a 'sweet spot' for viewing the display - you can sit anywhere within the display's normal LCD viewable angle.
Confused? Or perhaps you're wondering, if soft drinks can be advertised using this tech, why didn't we see it five years ago or more?
The challenges of generating 3-D images
Well here's the problem: take the lenticular sheet away from the display and you won't see an ordinary 2-D image. In fact, you'll see an image broken up into many different strips. The more strips - or views - the more complete the 3-D effect.
You can see right away that if you're splitting an image into strips and replicating the same image at a bunch of slightly different angles, that means the resolution you used to be able to dedicate to a single 2-D image you now have to 'share' among the different views.
So a 3-D image effectively lowers your display resolution. In the case of WOWvx, Philips says it cuts resolution threefold, thanks to some clever thinking. In other 3-D technologies, it decreases resolution by a factor equal to the number of views. Got nine views? Awesome 3-D, but only a ninth of the horizontal resolution.
Five years ago, a 19 inch (48cm) LCD monitor running at 1280 x 1024 cost $2,000. Divide the horizontal resolution by a third and you get a display running at about 426 x 341. Not exactly HDTV.
Nowadays, $2,000 in the consumer space buys you a 32 inch (81 cm) monitor running at 2560 x 1600. Or, in 3-D terms, 853 x 533 (more or less). That's still not awesome, but it approaches the resolution of standard PAL TV, at 768 x 576.
The other challenge back in 2004 was finding a PC powerful enough to do the complex signal processing to ensure the right bit of the image was positioned correctly under the right bit of the lenticular sheet.
Today, we have access to dual- and even quad-core processors in our home PCs, and lots and lots of RAM. We can also get our hands on powerful video processor cards, currently used mainly by gamers.
The actual 'trick' of generating a 3-D image on an LCD screen is simple, but the processing required to pull the trick off is complex. As our PCs continue to increase in power, that technology will filter down to consumer electronic devices, and 3-D will make it into our homes.
Making 3-D content
So if we have a 3-D TV and 3-D Blu-ray player (you'll need a very, very high resolution display to get a full 1080 vertical lines in 3-D though, but we believe it's just a matter of time), how do you actually get a 3-D movie?
What's great about the systems developed by Philips and SeeReal - which uses a similar lenticular sheet - is that content providers can choose how they want to encode their 3-D image.
They can use a stereoscopic camera, with two lenses, each of which captures a slightly different image. Or, more cleverly, they can shoot in conventional 2-D but then go in and add depth information.
Signal processing technology in the movie player -be it a PC or some future set-top box - then combines the depth information with the 2-D image to create a surprisingly convincing 3-D image.
What this means is that existing movies can be turned into 3-D films, much as some black-and-white films were colourised until people told the directors to stop. What's more, computer games that use what we currently call 3-D graphics can be turned into real 3-D automatically, thanks to software. So hang on to your copy of Doom 3 - it's going to get a lot more interesting!
When will 3-D TV arrive?
Which begs the question: how long until a 3-D TV has pride of place in your lounge room? Start saving now if you want, but don't hold your breath. The resolution challenge is a big one. We need displays capable of many thousands of pixels horizontally instead of the 1920 pixels you get on the most expensive TVs of today. We also need high definition players packed with the kind of processing power you currently find in a $3,000 PC.
If you want to experience 3-D TV right now, keep an eye out at your local shopping centre. Philips and SeeReal and others are rolling out displays to demonstrate the tech. The units will be big and flashy, showing ads most likely, but look closer.
You'll note the actual resolution of the image is pretty low compared to what you're enjoying from your Blu-ray system at home. Great for the novelty, but not quite up to the standards of your AV taste?
Thanks to the snowballing state of computer power in the world today, 3-D TV is an inevitability. It might take five years, or a decade, but it is coming. And when 3-D meets HD, that's when everyone will sit up and start spending.
The contenders
Several companies are hard at work on 3-D TV, or more correctly 3-D display technology. Here are the leaders.
Philips
Tech: WOWvx
Concept: Uses a slanted lenticular sheet on the surface of an LCD panel to scatter light and create depth perception.
Drawback: Cuts horizontal and vertical resolution, though not as much as similar technologies.
Expect it: At your local shopping centre next year.
Seereal
Tech: NextGen Stereo
Concept: As the name suggests, a next-generation 3-D display that doesn't cut back resolution like the lenticular system, works for multiple users at once and can even support real time filming in 3-D with a bolt-on camera.
Drawback: Some prototypes built, but the multi-user concept doesn't work yet, and ominously the company is still looking for an 'efficient light source'.
Expect it: To finally appear, minus some promised features, within the decade.
Mitsubishi
Tech: 3-D TV
Concept: A system for creating and transmitting 3-D TV, such as news and sporting events, using a grid of multiple cameras. Mitsubishi has also developed an anti-aliasing system for 3-D TV that vastly improves image quality.
Drawback: Requires not just one PC, but clusters of PCs to process the image. Relies on processing 'brute force' to get the job done.
Expect it: To be remembered as an important step on the road to 3-D.
Fraunhoffer Institute for Telecommunications
Tech: 3-D Travel Aid
Concept: A 30 inch (78 cm) display running at 1600 x 1200 shows maps but brings in elevation information and turns it into a 3-D image. Useful for planning trips, especially treks through rough terrain.
Drawback: Uses a camera to track the position of the user's eyes to adjust the image on the fly, which keeps costs and complexity up.
Expect it: To have been radically rethought since we last saw it in 2006.
