Millions of moviegoers have donned stereoscopic glasses to experience Hollywood films in 3-D. As the concept catches on in broadcast television, sports fans increasingly are putting on the filtering spectacles to watch their favorite stars compete in tournaments.
In the future, military robot operators may search for roadside bombs in 3-D.
Demand for 3-D television is growing, and technology efforts are under way to provide viewers with better resolution on high-definition displays. But scientists also are researching ways to get rid of the glasses to let viewers see three-dimensional images with the naked eye. Ultimately, the goal is to produce holographic images that can be projected onto coffee tables — a concept popularized in science fiction films including “Star Wars”
and “Minority Report.”
Humans perceive the world in three dimensions because of the two-inch distance between their eyes. Each eye sees a slightly different field of view and the brain combines the two perspectives. Depth perception results from the binocular vision system that calculates the distances between objects.
To capture the 3-D world on film, cinematic photographers place two cameras side-by-side like eyes and shoot footage through both lenses simultaneously. When the two image sets are superimposed over each other, they show varying perspectives of the same objects. Stereoscopic glasses filter one set of images into each eye so that the blended picture registers in three dimensions in the brain.
James Cameron’s 2009 film “Avatar” set a new film industry standard with its fully immersive qualities. His achievements are fueling an aggressive push into 3-D programming by the broadcast television industry, says Chris Lennon, chief technology organization group lead for Harris Corp., which produces communications equipment for commercial and governmental sectors. The company in April unveiled a suite of signal processing and encoding technologies that will allow the TV industry to broadcast programs in 3-D.
Initial 3-D offerings involve a single HD stream that is split in half — one half for each eye. The quality of the picture is the same, but it only has half the resolution, Lennon says. Full HDTV streams for each eye, similar to those seen on the silver screen, are several years away as technologists wrangle with bandwidth challenges.
Compressing the signals is one solution, but there are ways to attain 3-D video more efficiently than transmitting two full HD streams, Lennon says. There are several “2-D plus data” schemes. One method is to transmit a compressed HD signal with data representing images for the second eye. On the receiving end, the signal is decompressed to produce the two full HD pictures.
Reliant on imaging feeds, the Defense Department could benefit from those advancements. It has been shifting to HD video in recent years. Its next step could be to adopt 3-D systems. The power of 3-D will be evident in close-up video, Lennon says. Explosive ordnance teams that control robots to dismantle bombs may find good use for the technology. “Just as a 3-D image can be more pleasing to a home viewer, it can also provide more information to a government viewer,” says Lennon. Operators of remotely piloted aircraft, such as the Predator and the Reaper that fly high above the objects that they capture on video, may find the technology less useful because distance becomes a limiting factor.
On the commercial side, the gradual transition to HDTV is progressing at a steady pace. The adoption of 3-D TV by comparison is happening at a rapid and unprecedented clip, says Lennon. The Consumer Electronics Association estimates that a quarter of all televisions will be 3-D capable by 2013. But viewers still will have to peer through special glasses to see the displays properly.
“Getting rid of the glasses is probably the most complex problem to be solved in the area of 3-D TV,” says Lennon.
A number of scientists around the world are working on the problem. Experts predict that breakthroughs in display and imaging technologies are imminent in the coming decade and will make 3-D viewing without glasses a reality.
“Glasses-free 3-D TV will be a necessary interim step on the road to live holography,” says Lennon. “They share many of the same challenges.”
In its bid to host the 2022 World Cup, Japan announced that it plans to broadcast the tournament in live holography. It is an ambitious goal, but the nation is exploring the realm of the possible.
Japan’s National Institute of Information and Communications Technology last year demonstrated the world’s first live holography prototype. Research continues on conical screens through which rays of light travel to produce a 3-D image above a tabletop. A team of scientists also is developing a color holography system to capture and display live scenes in real time.
But technological and financial hurdles abound. “There are several of those to get through before you have no TV on the wall and holographic images on a coffee table,” says Lennon.