In the original Star Wars, R2D2 projects a holographic
video of Princess Leia's plea for help. That was in 1977. But
today, three-dimensional projection has moved beyond George Lucas'
imagination. Last month, a UK-based video company,Musion, successfully transmitted a holographic projection
from an office in London to
Berlin.
Unlike Star Wars, however, Musion transmitted a life-sized,
interactive holographic image of Musion director Ian O'Connell
using an optical illusion used to stun theatre-goers in the 19th
century.
The illusion, known as Pepper's Ghost, gave audiences the
perception of live actors or objects materialising into a scene on
stage. The Victorian theatre used a pane of glass at an angle to
the stage to throw a three-dimensional reflection of the actor onto
the stage. The effect is the same as when a car driver sees a
reflection of the dashboard in the side window.
Musion has taken this principle into the 21st century with its
patented Eyeliner 3D Projection System, which was invented by the
company's managing director, Uwe Maass, who drew inspiration from
the
Pepper's
Ghost illusion.
The main stumbling block with the Victorian approach was that a
large pane of glass was needed to reflect life-size images of the
actor. Not only was this unwieldy, but when a really large piece
was set at a 45 degree angle it would brake under its own weight.
Instead of glass, Musion uses a lightweight polymer foil and a
front projection system using a single projector. The image from
the projector screen is bounced onto the foil, making it appear
three-dimensional. The image is a bit like the reflection you see
of yourself in a shop windows.
Musion sees the technology as a way to revolutionise
video conferencing, where telepresence suites represent the
state of the art. In telepresence, each suite is equipped with
three to five high definition displays each requiring 3-6Mbps of
bandwidth. Musion requires only a single projector, which bounces a
video image through its patented foil set at 45 degrees to a
projector screen to create the holographic illusion. The main
difference between Musion's system and telepresence systems is that
its approach needs only 6-8Mbps.
Musion also uses different cameras to the high definition video
cameras used in telepresence suites. Images are transmitted 50
times a second as interlaced frames, where odd frame numbers are
transmitted, then even numbers every 1/50 of a second producing
moving images at 25 frames per second. O'Connell says this is
better for capturing moving images than 1080i, which displays the
whole frame 25 times a second.
The quality of the network connection is key to ensure the
illusion is realistic, says, O'Connell. "The codecs we use to
compress and decompress the video feed requires a glitch-free
network line."
The network is run by Masergy, which provided a communications
network capable of transporting high-definition images and
sound.
Video-conferencing is not the only application. "Most telecoms
companies see Musion mostly for use in the boardroom, but we think
it can be far more inclusive than that," says O'Connell. "It is
bi-directional - both sides interact in real-time, so it could work
in education where a teacher can be transmitted to a class of two
or three hundred, but by using touch-screen technology, she could
home in on any PC for a one to one with a particular student.
"Churches can transmit preachers, prisoners can visit their
families in their living rooms, engineers and inventors can
collaborate, musicians can appear in nightclubs to launch a new
album in 1,000 music stores simultaneously and the possibilities
for politicians are obvious.
"What the implications are for dating I dread to think. If you
think the internet transformed everything, if you think YouTube and
MySpace are great, where will this go?"