Communications groups have developed an affordable 3-D television that could be commercially available in three years, writes Karlin Lillington.

INITIALLY, THE large flatscreen television monitor in one corner of the meeting room looks pretty much like any other. But shift your viewing position slightly and it is clear that something is very odd. The heads of the running horses in the foreground actually seem to be sticking out of the screen.

Welcome to 3-D television, thanks to research and development by Spanish communications group Telefonica and electronics manufacturer Philips. No bi-coloured glasses are required; you just sit and watch. A series of film clips show the possibilities of the medium - a group of dancers undulate across the screen and when one throws a handful of rose petals towards the viewer, they seem to hang suspended in front of the screen.

The muzzle of a gun held by a soldier seems disconcertingly to emerge about a foot into space. A coiled snake strikes and it seems to half-exit the screen. A car appears ready to drive into the room.

So convincing is the display that a group of technology journalists, normally dulled by viewing numerous demonstrations of gizmos and gadgets, starts firing questions. Who made the programmes? Is this a prototype or a product? When will it be released? So how does it work?

According to Telefonica's research and development arm at its headquarters in Madrid, the service comprises a mix of a specially designed screen and a system for preparing programmes so that parts appear to be in three dimensions.

"It is stereo 3-D, with the ability to see 180 degrees around an object," says Gerard Mulá Rodríguez, R&D manager of Telefónica.

The three-dimensional effect is achieved by producing a grey scale 'disparity map' that converts the images on the screen to a series of greyscale objects. Items that will protrude are lighter in colour than others.

Meanwhile, the screens generate a 3-D view by placing millions of miniature lenses over each of the coloured pixels that make up the display. The lenses enable the viewer to see the screen from one of nine angles, while a processor in the television produces a slightly different view for each of the nine angles.

This lets a viewer see a different angle depending on where they are positioned before the screen - generating the 180-degree effect. It does, however, mean that viewers moving from side to side briefly pass in and out of positions that generate the 3-D effect. It also means that sometimes, only some of the objects onscreen have a strong 3-D presence.

The effect is similar to those 3-D postcards from childhood that need to be tilted to see the image. Nonetheless, the 3-D television experience is very convincing.

The technology isn't entirely new. Philips has had a 3-D screen on the market for a couple of years, but it has been very much a pricey early adopter trophy. Not many people would have paid €15,000 for a 42-inch television in 2006. But the WOWvx 3-D displays (www.wowvx.com) are now approaching half that amount, says Rodriguez, and quality keeps improving as prices drop.

Telefonica, which is in the television service provision market in several countries, is convinced that there will be demand for 3-D viewing. Rodriguez points to plans by Steven Spielberg to release the entire Star Wars catalogue in 3-D, as well as his upcoming film of Tintin. Shrek 4 is also promised in 3-D in 2010. Icelandic singer Bjork has released a 3-D song video.

The European Union has also put money towards developing 3-D television, with a four-year research project involving 200 people in 19 research groups winding up later this year (www.3-Dtv-research.org).

True 3-D, however, would involve holograms. If that seems too fantastical, some researchers predicted in February that initial holographic television displays will be available within two to three years, with proper commercial protoypes available in a decade.

Initially, these will probably have military and medical applications, say researchers. But strong demand for consumer versions are expected. Podge and Rodge will never be the same again.