23618894 3d Tv Technology Seminar

8/8/2019 23618894 3d Tv Technology Seminar

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An Assessment of

3DTV

Technologies

By:

Aniket Singh

B.Tech final year

EC A

Roll No. 0703231020

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CONTENTS:

3DTV

INTRODUCTION

ARCHITECTURE

MULTIVIEW AND STEROSCOPIC

DISPLAY

3D DISPLAY

CONCLUSION

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CHAPTER-1

3D TV

Creation of 3D Television

Tokyo - Imagine watching a football match on a TV that not only

shows the players in three dimensions but also lets you experience the

smells of the stadium and maybe even pat a goal scorer on the back.

Japan plans to make this futuristic television a commercial

reality by 2020as part of a broad 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.

"Can you imagine hovering over your TV to watch Japan versus

Brazil in the finals of the World Cup as if you are really there?" asked

Yoshiaki Takeuchi, development at Japan's Ministry of Internal

Affairs and Communications.

While companies, universities and research institutes around the

world have made some progress on reproducing 3D images suitable

for TV, developing the technologies to create the sensations of touch

and smell could prove the most challenging, Takeuchi said in an

interview with Reuters.

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Researchers are looking into ultrasound, electric stimulation and

wind pressure as potential technologies for touch.

Such a TV would have a wide range of potential uses. It could

be used in home-shopping programs, allowing viewers to "feel" a

handbag before placing their order, or in the medical industry,

enabling doctors to view or even perform simulated surgery on 3D

images of someone's heart.

The future TV is part of a larger national project under which

Japan aims to promote "universal communication," a concept

whereby information is shared smoothly and intelligently regardless

of location or language.

Takeuchi said an open forum covering a broad range of

technologies related to universal communication, such as languagetranslation and advanced Web search techniques, could be established

by the end of this year.

Researchers from several top firms including Matsushita

Electric Industrial Co. Ltd. and Sony Corp. are members of a report

on the project last month.

The ministry plans to request a budget of more than 1 billion yen to

help fund the project in the next fiscal year starting in April 2006

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CHAPTER-2

INTRODUCTION

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 withoutspecial glasses. This is first real time end-to-end 3D TV system with

enough views & resolution to provide a truly immersive 3D

experience.

2.1 Why 3D TV

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;

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3) computer imaging and digital special effects have been the latest

major novelty.

So the question is: what is the next revolution in cinema and

television going to be?

If we look at these stages precisely, we can notice that all types

of visual media have been evolving closer to the way we see things in

real life. Sound, colors and computer graphics brought a good part of

it, but in real life we constantly see objects around us at close range,

we sense their location in space, we see them from different angles as

we changeposition. This has not been possible in ordinary cinema.

Movie images lack true dimensionality and limit our sense that what

we are being seeing is real.

Nearly a century ago, in the 1920s, the great film director SergeiEisenstein said that the future of cinematography was the 3d motion

pictures. Many other cinema pioneers thought in the same way. Even

the Lumire brothers experimented with three-dimensional

(stereoscopic) images using two films painted in red and blue (or

green) colors and projected simultaneously onto the screen. Viewers

saw stereoscopic images through glasses, painted in the opposite

colors. But the resulting image was black-and-white, like in the first

feature stereoscopic film "Power of Love" (1922, USA, Dir. H.

Fairhal).

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CHAPTER-3

ARCHITECTURE OF 3D TV

Figure 5 shows the schematic representation of 3D TV system.

Fig.5.1 3D TV System

The whole system consists mainly three blocks:

1. Acquisition

2. Transmission

3. Display Unit

The system consists mostly of commodity components that are

readily available today. Note that the overall architecture of system

accommodates different display types. Let's understand the three

blocks one after another.

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5.1 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 theInternet.

As explain above each camera captures progressive high-

definition video in real time. Generally they are using 16 Basler

A101fc color cameras with 1300X1030, 8 bits per pixel CCD sensors.

The question might be arising in your mind that what are CCD imagesensors & MPEG coding?

5.1.1 CCD Image Sensors

Charge coupled device are electronic devices that are capable of

transforming a light pattern (image) into an electric charge pattern (an

electronic image). The CCD consists of several individual elements

that have the capability of collecting, storing and transporting

electrical charge from one element to another. This together with the

photosensitive properties of silicon is used to design image sensors.

Each photosensitive element will then represent a picture element

(pixel). With semiconductor technologies and design rules, structures

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are made that form lines, or matrices of pixels. One or more output

amplifiers at the edge of the chip collect the signals from the CCD.

An electronic image can be obtained by - after having exposed the

sensor with a light pattern - applying series of pulses that transfer the

charge of one pixel after another to the output amplifier, line after

line. The output amplifier converts the charge into a voltage. External

electronics will transform this output signal into a form suitable for

monitors or frame grabbers. CCDs have extremely low noise figures.

Figure 6 shows CCD sensors.

Fig.5.2 CCD Image SensorCCD image sensors can be a color sensor or a monochrome

sensor. In a color image sensor an integral RGB color filter array

provides color responsively and separation. A monochrome image

sensor senses only in black and white. An important environmental

parameter to consider is the operating temperature.

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5.1.2 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. Different algorithmic

'tools', developed for many applications, have been integrated into the

full standard. To implement all the features of the standard in all

decoders is unnecessarily complex and a waste of bandwidth, so a

small number of subsets of the full standard, known as profiles and

levels, have been defined. A profile is a subset of algorithmic tools

and a level identifies a set of constraints on parameter values (such as

picture size and bit rate). A decoder, which supports a particular

profile and level, is only required to support the corresponding subset

of the full standard and set of parameter constraints.

Now, the cameras are connected by IEEE-1394 High

Performance Serial Bus to the producer PCs. The maximum

transmitted frame rate at full resolution is 12 frames per seconds. Two

cameras each are connected to one of the eight producer PCs. All PCs

in this prototype have 3 GHz Pentium 4 Processors, 2 GB of RAM, &

run Windows XP.

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They chose the Basler cameras primarily because it has an

external trigger that allows for complete control over the video

timing. 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?

5.1.3 PCI Card

The power and speed of computer components has increased ata steady rate since desktop computers were first developed decades

ago. Software makers create new applications capable of utilizing the

latest advances in processor speed and hard drive capacity, while

hardware makers' rush to improve components and design new

technologiesto keep up with the demands of high end software.

Fig.5.3 PCI Card

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There's one element, however, that often escapes notice - the

bus. Essentially, a bus is a channel or path between the components in

a computer. Having a high-speed bus is as important as having a good

transmission in a car. If you have a 700-horsepower engine combined

with a cheap transmission, you can't get all that power to the road.

There are many different types of buses. In this article, you will learn

about some of those buses. 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. See the

figure 8.

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Fig.5.4 Arrays of 16 Cameras

The optical axis of each camera is roughly perpendicular to a

common camera plane. It is impossible to align multiple cameras

precisely, so they use standard calibration procedures to determine theintrinsic & extrinsic camera parameters. In general, the cameras can

be arranged arbitrarily because they are using light field rendering in

the consumer to synchronize new views. A densely spaced array

proved the best light fields capture, but high-quality reconstruction

filters could be used if the light field is under sampled.

5.2 Transmission

Transmitting 16 uncompressed video streams with 1300X1030

resolution & 24 bits per pixel at 30 frames per seconds requires 14.4

Gblsec bandwidth, which is well beyond current broadcast

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capabilities. For compression & transmission o1 dynamic muitiview

video data there are two basic design choices. Either the data from

multiple cameras is compressed using spatial or spatio-temporal

encoding, or each video stream is compressed individually using

temporal encoding. The first option offers higher compression, since

there is a lot of coherence between the views. However, it requires

that a centralized processor compress multiple video streams. This

compression-hub architecture is not scalable, since the addition of

more views will eventually overwhelm the internal bandwidth of the

encoder. So, they decided to use temporal encoding of individual

video stream on distributed processors.

This strategy has other advantages. Existing broadband

protocols & compression standards do not need to be changed for

immediate real world 3D TV experiments. This system can plug into

today's digital TV broadcast infrastructure & co-exist in perfect

harmony with 2D TV.

There did not have access to digital broadcast equipment, they

implemented the modified architecture as shown in figure 9.

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of Ethernet (the most widely installed LAN technology), that can

provide data transfer rates of about 1 gigabit per second (Gbps).

Gigabit Ethernet provides the capacity for server

interconnection, campus backbone architecture and the next

generation of super user workstations with a seamless upgrade path

from existing Ethernet implementations.

5.3 Decoder & Consumer Processing

The receiver side is responsible for generating the appropriate

images to be displayed. The system needs to be able to provide all

possible views to the end users at every instance. The decoder

receives a compressed video stream, decode it, and store the current

uncompressed source frame in a buffer as shown in figure 10. Each

consumer has virtual video buffer (VVD) with data from all current

source frames. (I.e., all acquired views at aparticular time instance).

Fig.5.6 Block Diagram of Decoder and Consumer processing

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The consumer then generates a complete output image by

processing image pixels from multiple frames in the VVB. Due to the

bandwidth 8 processing limitations it would be impossible for each

consumer to receive the complete source of frames from all the

decoders. This would also limit the scalability of the system.

Here is one-to-one mapping between cameras & projectors. But

it is not very flexible. For example, the cameras need to be equally

spaced, which is hard to achieve in practice. Moreover, this method

cannot handle the case when the number of cameras & projectors is

not same.

Another, more flexible approach is to use image-based

rendering to synchronize views at the correct virtual camera positions.

They are using unstructured lurnigraph rendering on the consumer

side. They choose the plane that is roughly in the center of the depth

of field. The virtual viewpoints for the projected images are chosen at

even spacing. Now focus on the processing for one particular

consumer, i.e., one particular view. For each pixel o (u, v) in the

output image, the display controller can determine the view number

v& the position (x, y) of each source pixel s (v, x, y) that contributesto it.

To generate output views from incoming video streams, each

output pixel is a linear combination of k source pixels:

0 (u, v) wts (v, x, y)

............ (1)

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The blending weights w can be pre-computed by the controller

based on the virtual view information. The controller sends the

position (x, y) of the k source pixels to each decoder v for pixel

selection. The index c of the requesting consumer is sent to the

decoder for pixel routing from decoders to the consumer. Optionally,

multiple pixels can be buffered in to the decoder for pixel block

compression before being sent over the network. The consumer

decompresses the pixel blocks & stores each pixel in VVB number v

at position (x, y). Each output pixel requires from k source frames.

That means that the maximum bandwidth on the network to the VVB

is k times the size of the output image times the number of frames per

second (fps). This can be substantially reduced if pixel block

compression is used, at the expense of more processing. So to provide

scalability it is important that this bandwidth is independent of thetotal number of the transmitted views. . The processing requirements

in the consumer are extremely simple. It needs to compute equation

(1) for each output pixel. The weights are pre computed & stored in a

lookup table. The memory requirements are k times the size of the

output image. Assuming simple pixel block compression, consumers

can easily be implemented in hardware. That means decoders,

networks, & consumers could be combined on the one printed circuit

board. Let's move on to the different types of display.

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CHAPTER-4

MULTIVIEW AUTO STEREOSCOPIC DISPLAY

6.1 Holographic Displays

It is widely acknowledged that Dennis Gabor invented the

hologram in 1948. he was working on an electron microscope. He

coined the word and received a Nobel Prize for inventing holography

in 1971. The holographic image is true three-dimensional: it can be

viewed in different angles without glasses. This innovation could be a

new revolution a new era of holographic cinema and of holographic

media in whole.

Holographic techniques were first applied to image display by

Leith & Upatnieks in 1962. In holographic reproduction, interference

fringes on the holographic surface to reconstruct the light wave front

of the original object diffract light from illumination source. A

hologram displays a continuous analog field has long been considered

the holy grail of 3D TV. Most recent device, the Mark-2

Holographic Video Display, uses acousto-optic modulators, beam

splitters, moving mirrors & lenses to create interactive holograms. In

more recent systems, moving parts have been eliminated by replacing

the acousto-optic modulators with LCD, focused light arrays, and

optically addressed spatial modulators, digital micro mirror devices.

Figure shows the holographic image.

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Fig.6.1 Holographic Image

All current holo-video devices use single-color laser light. To

reduce the amount of display data they provide only horizontal

parallax. The display hardware is very large in relation to size of the

image. So cannot be done in real-time.

6.2 Holographic Movies

We have developed the world's first holographic equipment with

the capability of projecting genuine 3-dimensional holographic films

as well as holographic slides and real objects for the multipleviewers simultaneously. Our Holographic Technology was primarily

designed for cinema. However it has many uses in advertising and

show business as well.

At the same time we have developed a new 3d digital image

processing and projecting technology. It can be used for creation the

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modern 3d digital movie theaters and for the computer modeling of 3d

virtual realities as well. On the same principle we have already tested

a system 3d color TV. In all cases audience can see colorful 3-d

inconvenient accessories.

Developed in the Holographic Laboratories of Professor Victor

Komar (NIKFI), these technologies have received worldwide

recognition, including an Oscar for Technical Achievement in

Hollywood, a Nika Film Award in Moscow, endorsement from MIT's

Media Lab and many others.

On this website you can find general information about our

technology, projects, brief history of 3d and holographic cinema,

investment opportunities and sales. For more specific questions please

check FAQ section on the ENQUIRE page. You can also send us a

message via email: the addresses are on the CONTACT page. Wehave developed the world's first holographic equipment the genuine 3-

dimensional holographic films as well as holographic slides and real

objects for the multiple viewers. Our Holographic Technology was

primarily designed for cinema. However it has many uses in

advertising and show business as well.

6.2.1 Volumetric Displays

It use a medium to fill or scan a three-dimensional space &

individually address & illuminate small voxels. However, volumetric

systems produce transparent images that do not provide a fully

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convincing three dimensional experience. Furthermore, they cannot

correctly reproduce the light field of a natural scene because of

their limited color reproduction & lack of occlusions. The design of

large size volumetric displays also poses some difficult obstacles.

6.2.2 Parallax Displays

Parallax displays emit spatially varying directional light. Much

of the early 3D display research focused on improvement to Wheat

stone's stereoscope. In 1903, F.Ives used a plate with vertical slits as a

barrier over an image with alternating strips of left-eye/right-eye

images. The resulting device is called a parallax stereogram. To

extend the limited viewing angle 8 restricted viewing position of

stereogram, Kanolt & H.Ives used narrower slits & smaller pitch

between the alternating image strips. These multiview images are

called parallax panorama grams.

Stereogram & panorama grams provide only horizontal parallax.

Lippmann proposed using an array of spherical lenses instead of slits.

This is frequently called a 'fly's eye" lens sheet, & resulting image is

called integral photograph. An integral is a true planar light field with

directionally varying radiance per pixel. Integral sacrifice significant

spatial resolution in both dimensions to gain full parallax. Researchers

in the 1930s introduced the lenticular sheet, a line of array of narrow

cylindrical lenses called Isnticules. Lenticular images found

widespread use for advertising, CD covers, & postcards. To improve

the native resolution of the display, H.Ives invented the multi-

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projector lenticular display in 1931. He painted the back of a

lenticular sheet with diffuse paint & used it as a projection surface for

39 slide projectors. Finally high output resolution, the large number of

views & the large physical dimensions of or display leads to a very

immersive 3D display. Other research in parallax displays includes

time multiplexed 8 tracking-bass systems. In time multiplexing,

multiple views are projected at different time instances using a sliding

window or LCD shutter. This inherently reduces the frame rate of the

display & may lead to noticeable flickering. Head-tracking designs

are mostly used to display stereo images, although it could also be

used to introduce some vertical parallax in multiview lenticular

displays. Today's commercial auto stereoscopic displays use

variations ofparallax barriers or lenticular sheets placed on the top of

LCD orplasma screens. Parallax barriers generally reduce some ofthe brightness & sharpness of the image. Here, this projector based

3D display currently has a native resolution of 12 million pixels.

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Fig.6.2 Images of a scene from the viewer side of the display (top row) and

as seen from some of the cameras (bottom row).

6.2.3 Multi Projector

Displays offer very high resolution, flexibility, excellent cost

performance, scalability, & large-format images. Graphics rendering

for multiprojector systems can be efficiently parallelized on clusters

of PCs using, for example, the Chromium API. Projectors also

provide the necessary flexibility to adapt to non-planar display

geometries. Precise manual alignment of the projector array is tedious

8 becomes downright impossible for more than a handful of

projectors or non-planar screens. Some systems use cameras in the

loop to automatically compute relative projectors poses for automatic

alignment. Here they will use static camera for automatic image

alignment & brightness adjustments of the projectors.

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CHAPTER-5

3D DISPLAY

This 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.

Figure shows a diagram of the multi-projector 3D displays with

lenticular sheets.

Fig.7.1 Projection-type lenticular 3D displays

They use 16 NEC LT-170 projectors with 1024'768 native

output resolution. This is less that the resolution of acquired &

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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.

Fig.7.2 Rear Projection and Front Projection

The projection-side lenticular sheet of the rear-projection

display acts as a light multiplexer, focusing the projected light as thin

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vertical stripes onto the diffuser. Close up of the lenticular sheet is

shown in the figure 6. Considering each lenticel to be an ideal

Pinhole camera, the stripes capture the view-dependent radiance

of a three-dimensional light field. The viewer side lenticular sheet acts

as a light de-multiplexer & projects the view-dependent radiance back

to the viewer. The single lenticular sheet of the front-projection screen

both multiplexes & demultiplexes the light.

The two key parameters of lenticular sheets are the field-of-view

(FOV) & the number of lenticules per inch (LPI). Here it is used 72" '

48" lenticular sheets with 30 degrees FOV & 15 LPI. The optical

design of the lenticules is optimized for multiview 3D display. The

number of viewing zones of a lenticular display is related to its FOV.

For example, if the FOV is 30 degrees, leading to 180/30 = 6 viewing

zones.

7.1 3D TV for 21st Century

Interest in 3D has never been greater. The amount of research

and development on 3D photographic, motion picture and television

systems is staggering. Over 1000 patent applications have been filed

in these areas in the last ten years. There are also hundreds of

technical papers and many unpublished projects.

I have worked with numerous systems for 3D video and 3D

graphics over the last 20 years and have years developed and

marketed many products. In order to give some historical perspective

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Ill start with an account of my 1985 visit to Exposition 85 in

Tsukuba, Japan, I spent a month in Japan visiting with 3D researchers

and attending the many 3D exhibits at the Tsukuba Science

Exposition. The exposition was one of the major film and video

events of the century, with a good chunk of its 2 1/2 billion dollar cost

devoted to state of the art audiovisual systems in more than 25

pavilions. There was the worlds largest IMAX screen, Cinema-U (a

Japanese version of IMAX), OMNIMAX (a dome projection version

of IMAX using fisheye lenses) in 3D, numerous 5, 8 and 10

perforation 70mm systems - several with fisheye lens projection onto

domes and one in 3D, single, double and triple 8 perforation 35mm

systems, live high definition (1125 line) TV viewed on HDTV sets

and HDTV video projectors (and played on HDTV video discs and

VTRs), and giant outdoor video screens culminating in Sonys 30meter diagonal Jumbotron (also presented in 3D). Included in the 3D

feast at the exposition were four 3D movie systems, two 3DTV

systems (one without glasses), a 3D slide show, a Pulfrich

demonstration (synthetic 3D created by a dark filter in front of one

eye), about 100 holograms of every type, size and quality (the

Russians were best), and 3D slide sets, lenticular prints and

embossed holograms for purchase. Most of the technology, from a

robot that read music and played the piano to the worlds largest

tomato plant, was developed in Japan in the two years before the

exposition, but most of the 3D hardware and software was the result

of collaboration between California and Japan. It was the chance of a

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lifetime to compare practically all of the state of the art 2D and 3D

motion picture and video systems, tweaked to perfection and running

12 hours a day, seven days a week. After describing the systems at

Tsukuba, I will survey some of the recent work elsewhere in the

world and suggest likely developments during the next decade.

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CHAPTER-6

CONCLUSION

Most of the key ideas for 3D TV systems presented in this

paper have been known for decade, such as lenticular screens,

multi projector 3D displays, and camera array for acquisition.

This system is the first to provide enough view points and

enough pixels per view points to produce an immersive and

convincing 3D experience. Another area of future research is

to improve the optical characteristic of the 3D display

computationally. This concept is computational display.

Another area of future research is precise color reproduction

of natural scenes on multiview display.

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23618894 3d Tv Technology Seminar