3D Television
Three-dimensional TV is expected to be the next revolution in the TV history. They implemented
a 3D TV prototype system with real-time acquisition transmission, & 3D display of dynamic
scenes. They developed a distributed scalable architecture to manage the high computation &
bandwidth demands. 3D display shows high-resolution stereoscopic color images for multiple
viewpoints without special glasses. This is first real time end-to-end 3D TV system with enough
views & resolution to provide a truly immersive 3D experience. Japan plans to make this
futuristic television a commercial reality by 2020as part of abroad national project that will bring
together researchers from the government, technology companies and academia. The targeted
"virtual reality" television would allow people to view high definition images in 3D from any
angle, in addition to being able to touch and smell the objects being projected upwards from a
screen to the floor.
The evolution of visual media such as cinema and television is one of the major hallmarks of our
modern civilization. In many ways, these visual media now define our modern life style. Many
of us are curious: what is our life style going to be in a few years? What kind of films and
television are we going to see? Although cinema and television both evolved over decades, there
were stages, which, in fact, were once seen as revolutions:
1) at first, films were silent, then sound was added;
2) cinema and television were initially black-and-white, then color was introduced;
3) computer imaging and digital special effects have been the latest major novelty.
BASICS OF 3D TV
Human gains three-dimensional information from variety of cues. Two of the most important
ones are binocular parallax & motion parallax.
A. Binocular Parallax
It means for any point you fixate the images on the two eyes must be slightly different. But the
two different image so allow us to perceive a stable visual world. Binocular parallax defers to the
ability of the eyes to see a solid object and a continuous surface behind that object even though
the eyes see two different views.
B. Motion Parallax
It means information at the retina caused by relative movement of objects as the observer moves
to the side (or his head moves sideways). Motion parallax varies depending on the distance of the
observer from objects. The observer's movement also causes occlusion (covering of one object
by another), and as movement changes so too does occlusion. This can give a powerful cue to the
distance of objects from the observer.
C. Depth perception
It is the visual ability to perceive the world in three dimensions. It is a trait common to many
higher animals. Depth perception allows the beholder to accurately gauge the distance to an
object. The small distance between our eyes gives us stereoscopic depth perception[7]. The brain
combines the two slightly different images into one 3D image. It works most effectively for
distances up to 18 feet. For objects at a greater distance, our brain uses relative size and motion
As shown in the figure, each eye captures its own view and the two separate images are sent on
to the brain for processing. When the two images arrive simultaneously in the back of the brain,
they are united into one picture. The mind combines the two images by matching up the
similarities and adding in the small differences. The small differences between the two images
add up to a big difference in the final picture ! The combined image is more than the sum of its
parts. It is a three-dimensional stereo picture.
ARCHITECTURE OF 3D TV
The whole system consists mainly three blocks:
1 Aquisition
2. Transmission
3. Display Unit
A. Acquisition
The acquisition stage consists of an array of hardware-synchronized cameras. Small clusters of
cameras are connected to the producer PCs. The producers capture live, uncompressed video
streams & encode them using standard MPEG coding. The compressed video then broadcast on
separate channels over a transmission network, which could be digital cable, satellite TV or the
Internet.
Generally they are using 16 Basler A101fc color cameras with 1300X1030, 8 bits per pixel CCD
sensors.
1) CCD Image Sensors: Charge coupled devices are electronic devices that are capable of
transforming a light pattern (image) into an electric charge pattern (an electronic image).
2) MPEG-2 Encoding: MPEG-2 is an extension of the MPEG-1 international standard for digital
compression of audio and video signals. MPEG-2 is directed at broadcast formats at higher data
rates; it provides extra algorithmic 'tools' for efficiently coding interlaced video, supports a wide
range of bit rates and provides for multichannel surround sound coding. MPEG- 2 aims to be a
generic video coding system supporting a diverse range of applications. They have built a PCI
card with custom programmable logic device (CPLD) that generates the synchronization signal
for all the cameras. So, what is PCI card?
3) PCI Card:
There's one element the bus. Essentially, a bus is a channel or path between the components in a
computer. We will concentrate on the bus known as the Peripheral Component Interconnect
(PCI). We'll talk about what PCI is, how it operates and how it is used, and we'll look into the
future of bus technology.
All 16 cameras are individually connected to the card, which is plugged into the one of the
producer PCs. Although it is possible to use software synchronization, they consider precise
hardware synchronization essential for dynamic scenes. Note that the price of the acquisition
cameras can be high, since they will be mostly used in TV studios. They arranged the 16 cameras
in regularly spaced linear array
3D DISPLAY
3This is a brief explanation that we hope sorts out some of the confusion about the many 3D
display options that are available today. We'll tell you how they work, and what the relative
tradeoffs of each technique are. Those of you that are just interested in comparing different
Liquid Crystal Shutter glasses techniques can skip to the section at the end. Of course, we are
always happy to answer your questions personally, and point you to other leading experts in the
field[4]. Figure shows a diagram of the multi-projector 3D displays with lenticular sheets.
They use 16 NEC LT-170 projectors with 1024'768 native output resolution. This is less that the
resolution of acquired & transmitted video, which has 1300'1030 pixels. However, HDTV
projectors are much more expensive than commodity projectors. Commodity projector is a
compact form factor. Out of eight consumer PCs one is dedicated as the controller. The
consumers are identical to the producers except for a dual-output graphics card that is connected
to two projectors. The graphic card is used only as an output device. For real-projection system
as shown in the figure, two lenticular sheets are mounted back-to-back with optical diffuser
material in the center. The front projection system uses only one lenticular sheet with a retro
reflective front projection screen material from flexible fabric mounted on the back. Photographs
show the rear and front projection
