2. CONTENT
Introduction
History
How we see 3D
How to create 3D ?
Common 3D display technique
Viewing through glass
Anaglyphic 3D
Polarization 3D
Active glasses
Auto stereoscopic display
Lenticular lenses
Parallax barrier
Architecture of 3D TV
Transmission
3D display
Application
Advantages and disadvantage
3. INTRODUCTION
A 3D television is a television that employs techniques
of 3D presentation, such as stereoscopic capture, multi-
view capture, or 2D plus depth, and a 3D display a
special viewing device to project a television program
into a realistic three-dimensional field.
Three dimensional TV is expected to be next revolution
in the TV history.
4. HISTORY
The stereoscope was first invented by Sir Charles
Wheatstone in 1838.
Stereoscopic 3D television was demonstrated for
the first time on 10 August 1928.
A stereoscope is a device for viewing
a stereoscopic pair of separate images, depicting
left-eye and right-eye views of the same scene, as
a single three-dimensional image.
5. HOW WE SEE 3D
Basic principle tricking our dumb, binocular brain
into interpreting a 2Dimage into one with depth.
A key part of this process is binocular disparity. It
means each eye has a slightly different viewpoint.
When an object is far away, the light traveling to one
eye is parallel with the light traveling to the other
eye. But as an object gets closer, the lines are no
longer parallel --they converge and our eyes shift to
compensate.
6. HOW TO CREATE 3D?
It involves the usage of two cameras (or a camera having
two lenses), placed side by side with the center of their
lenses spaced approximately and ideally, the same
distance as the space between our eyes.
Both cameras record in sync and the resulting left and
right eye videos or images are then edited and presented
to the viewer (in cinemas) via different techniques.
7. COMMON 3D DISPLAY TECHNOLOGY
Projecting stereoscopic image pairs to the viewer
include:
Passive glass:
Anaglyphic 3D (with red-blue glasses)
Polarization 3D (with polarized glasses)
Active glass: Alternate-frame sequencing
Auto stereoscopic displays (without glasses)
8. VIEWING THROUGH GLASSES
Two sets of images are meant to be seen by only
particular eye.
Hence each eye can only see one set of images,
your brain interprets this to mean that both eyes
are looking at the same object.
That's what creates the illusion of depth.
9. ANAGLYPHIC 3D
RED-BLUE GLASSES
There are two sets of images slightly offset from one
another. One will have a blue tint to it and the other
will have a reddish hue.
Anaglyph glasses use two different color lenses to
filter the images you look at on the television screen.
The two most common colors used are red and blue.
10. POLARIZATION 3D
POLARIZED GLASSES
Light waves of two images are projected at certain angles.
Each lens only allows light to pass through that is polarized
in a compatible way.
It is more popular than anaglyph glasses because the
polarization don't distort the color of the image.
Hence it is popular in projector based display.
11. ACTIVE GLASSES
ALTERNATE-FRAME SEQUENCING
An active glasses system alternates between the two sets
of images at very high speeds.
Active glasses have infrared (IR)sensors.
As the 3-D content appears on the screen, the picture
alternates between two sets of the same image.
12. ADVANTAGE OF ACTIVE GLASSES OVER
PASSIVE GLASSES
It's easier to present 3-D in HD content using active
glasses than with passive glasses.
That's because with a passive glass system, the television
has to display two sets of images at the same time.
An active glasses system alternates between that two
sets of images at very high speeds--it's less information
for the television to handle at any particular moment.
13. BUT STILL HAVE A PROBLEM WITH
THOSE GLASSES?
Stereoscopic method leads to problems:
The glasses are really cumbersome and expensive, and
you don't want to accidentally sit on one or lose it. And
what to do when we don't have enough lenses.
Plus, it takes away the simplicity of television as it
stands today, where you simply hit the remote and start
watching.
Also, without the glasses, any 3D content is completely
unusable.
15. LENTICULAR LENSES
Basically A lenticular lens is an array of
magnifying or directing lenses, designed so
that when viewed from slightly different
angles, different images are magnified.
Lenticulars are tiny lenses on the base side
of a special film.
The screen displays two sets of the same
image. The lenses direct the light from the
images to your eyes each eye sees only one
image.
It creates a particular space from which
images can seen clearly called ‘sweet spot’.
16. PARALLAX BARRIER
On a 3D screen, a very fine grating, called a "parallax
barrier", is placed in front of the LCD screen.
The parallax barrier is a fine grating of liquid crystals
placed in front of the screen, with slits in it that
correspond to certain columns of pixels of the screen.
It does the job of the polarizing glasses, directing
light from each image slightly in different direction so
that at a so-called "sweet spot" about 30 inches in front
of the screen the two images are separated just enough
that the brain will create a composite 3D image.
17. ADVANTAGE OF PARALLAX BARRIER
OVER LENTICULAR LENSES
parallax barrier can be switched on and off with
ease (one button on the remote is all it would take),
allowing the TV to be used for 2D or3D viewing.
So on a computer monitor, you could play video
games in full 3D and then easily switch to 2D mode
for your work requirements.
21. APPLICATION OF 3D TV
video games
TV
applications for physicists, scientists, and engineers
could also be extremely useful.
Richer ,Lifelike and entertaining experience than 2D
TV for home users.
Future use in mobile.
23. CONCLUSION
Thus we have seen various technologies used for 3D
imaging and viewing.
We also explained technology of 3D TV, discussed
various aspects and features of 3D TV.
Another area of future research is precise colour
reproduction of natural scenes on multiview
displays.
In future we will be able to touch and smell the
objects being projected from a screen to the viewers.
