This document discusses various 3D display techniques. It describes techniques that require glasses like anaglyph, polarization and eclipse method. It also covers glasses-free techniques like guided light, lenticular screens and parallax barriers. The document notes the challenges with current auto-stereoscopic displays in terms of higher costs, reduced resolution and limited viewing angles.

2. INDEX
• OVERVIEW
• 3D DISPLAY TECHNIQUES With Glasses
• ANAGLYPH
• POLARIZATION
• ECLIPSE METHOD
• 3D DISPLAY TECHNIQUES Without Glasses
• GUIDED LIGHT
• LENTICULAR SCREEN
• PARALLAX BARRIER
• OBSTACLES

3. OVERVIEW
HUMAN VISION & PERCEPTION OF 3D WORLD
• Human eyes are equipped with an absolutely amazing
binocular vision system. For objects up to about 20 feet (6 to
7 meters) away, the binocular vision system lets us easily tell
with good accuracy how far away an object is.
• The binocular vision system relies on the fact that our two
eyes are spaced about 2 inches (5 centimeters) apart.
Therefore, each eye sees the world from a slightly different
perspective, and the binocular vision system in our brain uses
the difference to calculate distance. Our brain has the ability
to correlate the images it sees in its two eyes even though
they are slightly different.

4. PRINCIPLE OF 3D DISPLAY
• Main concept behind 3D display is to
generate a sense of variation in depth.
To achieve this, two perspective of a
single image, each for one eye, is used.
The principle is to send an individual
image to each eye. our eyes can
correlate these images automatically
because each eye sees only one of the
images.

5. 3D TECHNIQUES WITH GLASSES
ANAGLYPH
In this system, two images are displayed on the
screen, one in red and the other in blue (or green).
The filters on the glasses allow only one image to
enter each eye, and our brain does the rest.
DRAWBACK: We cannot have a color movie when
we are using color to provide the separation, so the
image quality is not nearly as good as with the
polarized system.

6. 3D TECHNIQUES WITH GLASSES
POLARIZATION
Two synchronized projectors project two
respective views onto the screen, each with a
different polarization. The glasses allow only one of
the images into each eye because they contain
lenses with different polarization.
DRAWBACK: It's very difficult to use the
polarization technique for home theater systems --
most methods would require to coat our television
screen with a special polarizing film first.

7. 3D TECHNIQUES WITH GLASSES
ECLIPSE METHOD:
Liquid crystal shutter glasses are used in conjunction with a display screen.
Each eye's glass contains a liquid crystal layer which has the property of
becoming dark when voltage is applied, being otherwise transparent.
 The glasses are controlled by an infrared, radio frequency that sends a
timing signal that allows the glasses to alternately darken over one eye, and
then the other, in synchronization with the refresh rate of the screen.

8. 3D TECHNIQUES WITH GLASSES

9. PROBLEM
The most common 3D displays require
users to wear special glasses, which
has limited the technology’s
popularity. Now researcher and
vendors are working on glasses-free
3D displays.

10. SOLUTION
Using auto stereoscopic displays to
generate 3D images without glasses.

11. AUTO STEREOSCOPIC DISPLAY
There are two broad classes of auto
stereoscopic displays:
1). Multi view
2). Light field

12. MULTIVIEW
A multi view display uses optics to
render two or more views of a
scene, which the user’s optical system
fuses into single 3D image

13. LIGHT-FIELD
Light field displays generate pixel-like elements
that transmit image-brightness data and
information about the direction and angle that
light rays would travel from an object to a
viewer’s eyes. This makes it easier for the optical
system to interpret the image properly.

14. 3D TECHNIQUES WITHOUT GLASSES
Guided light:
This techniques use
special holographic
prisms that organize
multiple high end
projectors output into a
single 3D image.

15. 3D TECHNIQUES WITHOUT GLASSES
Lenticular sheet
This method relies on a display coated
with a lenticular film. Lenticuler 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 our eyes -- each eye sees only
one image. Our brain puts the images
together and interpret it as a three-
dimensional image.

16. 3D TECHNIQUES WITHOUT GLASSES
• Parallax barrier:
• A parallax barrier is a device placed in
front of an image source, such as a liquid
crystal display, to allow it to show a
stereoscopic image without 3D glasses.
Placed in front of the normal LCD, it
consists of a layer of material with a
series of precision slits, allowing each eye
to see a different set of pixels, so creating
a sense of depth through parallax in an
effect similar to what lenticular printing
produces for printed products.

17. OBSTACLES
• Because they entail complex projection and
display technologies, auto stereoscopic system
cost substantially more than traditional 3D
displays.
• To render multiple viewing angles for a group of
users, lenticular and barrier techniques lose
resolution.
• Moreover they offer a limited number of viewing
angles from which users can see 3D images.