Sathu G Rajan Nov. 2006

8/9/2019 Sathu G Rajan Nov. 2006

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Seminar Report

on

TELE - IMMERSION,

Submitted in partial fulfillment of th e requirements for the award of the degree of

Bachelor of Technologyy p t . .-. a. 2-

* ' .,in , - ir

- 7 ,

Computer Science and Engineering

by

SATHU G. RAJAN

b4

-C

November 2006

Department of Computer Science and EngineeringSree Narayana Gurukulam College of Engineering, Kolenchery


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Tele - Immersion

ACKNOWLEDGEMENT

Firstly I would like to express my sincere gratitude to the Almighty for His

solemn presence throughout the seminar study.I would also like to exp ress my

special thanks to the Principal Prof.K. Rajendran for providing an opportunity

to undertake this seminar .I am deeply indebted to our seminar coordinator Mr.

Saini Jacob, Assistant Professor in the Department of Computer Science and

Engineering for providing me with valuable advice and guidance during the

course of the study.

I would like to extend my heartfelt gratitude to the Faculty of the Department

of Computer Science and Engineering for their constructive support and

cooperation at each and every juncture of the seminar study.

Finally T would like to express my gratitude to Sree Narayana Gurukulam

College of Engineering for providing me with all the required facilities

without which the seminar study would not have been possible.

Dept. of CSE SNGCE. K o l ~ r z I ~ t ~


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TELE-I MMERSION

ABSTRACT

Tele-immersion is a technology to be implemented

together in a simulated environment to interact. Users will feel like they are actually

looking, talking, and meeting with each other face-to-face in the same room. This is

achieved using computers that recognize the presence and movements of individuals and

objects tracking those individuals and images and reconstructing them onto one stereo-

immersive surface. 3D reconstruction for tele-immersion is performed using stereo,

which means two or more cameras take rapid sequential shots of the same object,

continuously performing distance calculations, and projecting them into the computer-

simulated environment, as to replicate real-time movement.

Tele immersion is a technology that will be implemented

with Intemet2lt will enable users in different geographical locations to come together and

interact in a simulated holographic environment. Users will feel as if they are actually

1looking, talking and meeting with each other face to face in the same place, even though!they may be miles apart physically. In a tele immersive environment, computers!recognize the presence and movements of individuals as well as physical and virtual11I objects. They can then track these people and non-living objects, and project them in a

realistic way across many geographic locations.

It has varied applications and it will significantly affect the

educational, scientific and medical sectors.

Its main application is in video conferencing and it

takes video conferencing to the next level.

It is a dynamic concept, which will transform the way

human interact with each other and the world in general.

Dept-of CSE SNGCE,Kolenchery


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TELE-IMMERSION

CONTENTS

Introduction ....1The H istory....What is tele- immersion? ....

Requirements of Tele immersion....

3D environment scanning ........econstruction in a holographic environm ent 6

Projective and display technologies....Tracking technologies ....7Moving sculptures ....

Audio technologies ....

Powerhl networking ....

Computational needs ....9Telecubicle .... 10Tele imm ersion studio.... 1

Applications....12

Challenges of Tele-Immersion.... 5

Solution....16About Internet2.... 16

....esktop Supercomputers 17....andwidth issues 17

....urrent developments 18Conclusion .... 0Future scope .... 1Bibliography .... 2

Dcpr.of CSE SKGCE.E;G!~~; :~~,


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INTRODUCTIONI Tele-immersion, a new medium for human interaction

enabled by digital technologies, approximates the illusion that a user is in the sameI1 physical space as other people, even through the other participants might in fact beI

I .hundreds or thousands of miles away. It combines the display and interaction~

techniques of virtual reality with new vision technologies that transcend the traditional

limitations of a camera. Rather than merely observing people and their immediate

environment from one vantage point, tele- immersion stations convey them as "moving

sculptures,'' without favoring a single point of view. The result is that all theparticipants, however distant, can share and explore a life-size space.

I

Beyond improving on videoconferencing, tele-immersion~

was conceived as an ideal application for driving network-engineering research,

specifically for Tnternet2, the primary research consortium for advanced network

studies in the U.S. If a computer network can support tele-immersion, i t can probablyI

support any other application. This is because tele-immersion demands as little delay as~

possible from flows of information ( and as little inconsistency in delay ), in addition to'

the more common demands for very large and reliable flows.

Tele-immersion car? be of i~nmense use i n rnedict~l

industry and i t also finds its application i n the field of edi~cation

TH E HJSTORY

It was i11 1965 that, Ivan Sutherland, proposed the conceptI

of the 'Ultimate Display'. It described a graphics display that would allow the user to

experience a completely computer-rendered environment. 'The term Tele-immersion

\\as first used in October 1996 as the title of a workshop organized by EVL and'

sponsored by Advanced Network & Services, Inc. to bring together researchers in,

distributed computing, collaboration, VR, and networking. At this workshop. specific

attention was paid to the future needs of applications in the sciences. engineering- an d

education. In 1998 Abilene, a backbone research project was launched and no\\ senes

as the base for Internet-2 research. Tele-immersion is the application that \ \ i l l dr i \e

forward the research of Internet-2.

Dept.of CSE 1 sh(;c~-x :-- -_ - -.


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TELE-IMMERSION

WHAT IS TELE- IMMERSION ?

I

!

Tele-immersion enables users at geographically distributed

sites to collaborate in real time in a shared, simulated, hybrid environment as if they wereI

in the same physical room.

It is the ultimate synthesis of media technologies:

J 3D environment scanning.

J Projective and display technologies.Tracking technologies.

J Audio technologies.

J Powerful networking.

The considerable requirements for tele-imm ersion system,

such as high bandwidth, low latency and low latency variation make it one of the most

challenging net applications. This application is therefore considered to be an ideal driverfor the research agendas of the Internet2 community.

Tele-immersion is that sense of shared presence with

distant individuals and their environments that feels substantially as if they were in one's

own local space. This kind of tele-immersion differs significantly from conventional

video teleconferencing in that the use's view of the remote environment changes

dynamically as he moves his head.

Dept.of CSE 2 SNC;CE.Kolencher>


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TELE-IM MERSION

REQUIREMENTS OF TELE-IMMERSION

Tele-immersion is the ultimate synthesis of media

technologies. It needs the best out of every media technology. The requirements are

given below.

3D ENVIRONMENT SCANNING

For a better exploring of the environment a stereoscopic

view is required. For this, a mechanism for3D environment scanning method is to be

used. It is by using multiple cameras for producing two separate images for each ofeyes. By using polarized glasses we can separate each of the views and get a 3D view.

The key is that in tele-immersion, each participant must

have a personal view point of remote scenes-in fact, two of them, because each eye

must see from its own perspective to preserve a sense of depth. Furthermore,

participants should be free to move about, so each person's perspective will bei n

constant motion. Tele-imm ersion demands that each scene be sensedi n a manner that is

not biased toward any particular viewpoint (a camera, in contrast, is locked intoI portraying a scene from its own position). Each place, and the people and things in it,I

has to be sensed from all directions at once and conveyed as if it were an animated

three-dimensional sculpture. Each remote site receives information describing the

whole moving sculpture and renders viewpoints as needed locally. The scanning

process has to be accomplished fast enough to take place in real time at most within a

small fraction of a second.

The sculpture representing a person can then be updated

quickly enough to achieve the illusion of continuous motion. This illusion starts to

appear at about 12.5 frames per second (fps) but becomes robust at about 25 fps and

better still at faster rates.

Measuring the moving three-dimensional contours of the

inhabitants of a room and its other contents can be accomplished in a variety of ways.

In 1993, Henry Fuchs of the University of North Carolina at Chapel Hill had proposed

'one method, known a s the "sea o f cameras" approach, in w hich the viewpoints o f many

cameras are compared. In typical scenesi n a human environment, there will tend to be

Dept.of CSE 3 SNGC E.Kolencher!


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TELE-IMMERSION

Ivisual features, such as a fold in a sweater, that are visible to more than one camera. By

comparing the angle at which these features are seen by different cameras, algorithmscan piece together a three- dimensional model of the scene.

This technique had been explored in non-real-time

'configurations, which later culminated in the "Virtualized Reality "demonstration at

Carnegie Mellon University, reported in 1995. That setup consisted of 51 inward-

looking cameras moun ted on a geodesic dom e. Because it was not a real- ime device,it could no t be used for tele-immersion.

Ruzena Bajcsy, head of GRASP ( General Robotics,Automation, Sensing and Perception) Laboratory at the University of Pennsylvania,

was intrigued by the idea of real-time seas of cameras. Starting in 1994 , small scale

,"puddles" of two or three cameras to gather real-world data for virtual- realityapplications w as introduced.

But a sea of cameras in itself isn't complete solution.

Suppose a sea of cameras is looking at a clean white wall. Because there are no surface

futures, the cameras have no information with which to build a sculptural model. Aperson can look at a white wall without being confused. Humans don't worry that a

wall might actually be a passage to an infinitely deep white chasm, because we don't

I rely on geometric cues alone- we also have a model of a room in our minds that can

'

rein in errant mental interpretations. Unfortunately, to today's digital cameras, a

person 's forehead or T-shirt can present the same challenge as a white wall, and

today's software isn't smart enough to undo the confusion that results.

Researchers at Chapel Hill came with a novel method that

has show n prom ise for overcoming this obstacle, called" imperceptible structured light

-' r ISL. Conventional light bulbs flicker 50 or60 times a second, fast enough for the

.flickering to be generally invisible to the human eye. Similarly, ISL appears to the

human eye as a continuous source of white light, like an ordinary light bulb, but in fact

it is filled with quickly changing patterns visible only to specialized, carefullyI synchronized cameras. These patterns fill in voids such as white wall with imposedI

features that allow a sea of cameras to complete the measurements. If imperceptible

structured light is not used, then there may be holes in reconstruction data that result


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from occlutions, areas that aren't seen by enough cameras, or areas that don't provide

distinguishing surface features.To accomplish the simultaneous capture and display an

office of the fbture is envisioned where ceiling lights are controlled cameras and

"smart". projectors that are used to capture dynamic image-based models with

imperceptible structured light techniques, and to display high-resolution images on

designated display surfaces. By doing simultaneously on the designated display

surfaces, one can dynamically adjust or auto calibrate for geometric, intensity, and

1 resolution variations resulting from irregular or changing display surfaces, or

overlapped projector images.

Now the current approach to dynamic image-based

.modeling is to use an optimized structured light scheme that can capture per-pixel depth

and reflectance at interactive rates. The approach to rendering on the designated

(potentially irregular) display surface is to employ a two-pass projective texture scheme

to generate images that when projected onto the surfaces appear correct to a moving

head-tracked observer.


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1 RECONSTRlJCTION IN A HOL OGR APH lC EN VIIIONMBNrl'1k1

The process of reconstruction of image occursi n

a/ holographic environment. At the translnitting end. the3d imagc scanned i s generatedusing two techniques. The reconstri~ction process is different fhr sharedtable and ic3d

I approach.

I Sharer1 Table App roachI

Here, the depth of the 3d image is calculated usirig 3d wireI

ffames. this technique uses various calncraviews and con~plexnlage analqsis algorithms

to calci~latche depth.~

1 Assulning that the geonletrical paralnetcrs o f the multi-I

Iview c apture device, the virtual gcene and thc virtual cam era are n ell fittcdt o each otl~er.

I .~t is cnsurcd that thc scenc is viewed in thc right pcrspectivc view, m e n wl~ilc. hanging

I the vien ing position.

r Ic3d(incornplete 3d) ApproachI

In this case, a colnmon teuturc surfact: is extracted from the

alailable camera vielvs and thc depth information is codcd in an associated disparit~

nidp. This representation can be encoded into a mpeg-3 vidcool~ jcc t .which is then

transmitted.

The decoded disparities are scaled according to the uscr's

3d viewpoint in the virtual scene, anda disparity-contt.olled prq jec tiot~ s carried out. 'I'l~c

36 perspective of the person cha nges Lvith the ~n ov eni en t f the virtual cam era.

In both the approaches, at the receiving end the entirely

composed 3d scene is rendered onto the 2d display of the terminal by using a virtual

a m e r a . the position of the virtual camera coincides with the current position of the

conferee's head. for this purpose the head position is permanently registered by a head

tracker and the virtual ca mera is moved w ith the head.


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PROJECTIVE & DISPLAY TECHNOLOGIES

By using tele-immersion a user must feel that he is

immersed in the other person's world. For this, a projected view of the other user's

world is needed. For producing a projected view, big screen is needed. For better

projection, the screen must be c u ~ e dnd spe cial projection cameras are to be used.

TRACKING TECHNOLOGIES

It is great necessity that each of the objects in the

imm ersive environment be tracked so that we get a real world experience. This is done

by tracking the move ment of the user and ad justing the came ra accordingly.

Head & Hand tracking

The UNC and Utah sites collaborated on several joint

design-and-manufacture efforts, including the design and rapid production of a head-

tracker component (HiBall) (now used in the experimental UNC wide-area ceiling

.tracker). Precise, unencum bered tracking of a u ser's head and hands ov er a room sized

working area has been an elusive goal in modern technology and the weak link in mostvirtual reality systems. Currant commercial offerings based on magnetic technologies

perform poorly around such ubiquitous, magnetically noisy computer components as

CR Ts, while optical-based products have a very small working volume and illuminateda beacon.targets (LEDs). Lack of an effective tracker has crippled a host of augmentedI

reality applications in which the user's views of the local surroundings are augmented

by synthetic data (e.g., location of a tumorin the patient's brain or the removal path of

a part from w ithin a complicated piece of machinery).

MOVING SCULPTURES

It combines the display and interaction techniqu es o f virtual

reality with new vision technologies that transcend the traditional limitations of a

camera. Rather than merely observing people and their immediate environment from

one vantage point, tele-immersion stations convey them as" moving sculptures",

without favoring a single point of view. The result is that all the participants, however

distant,'can share and explore a life size space.

Dept.of CSE 7 SNC;CE.Kolencher!


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AUDIO TECHNOLOGIES

For true immersive effect the audio system has to beextended to another dimension, i.e., a 3 D sound capturing and reproduction method has

to be used. This is necessary to track each sound source's relative position.

POWERFUL NETWORKING

The considerable requirements for tele-immersion system,

such as high bandwidth, low latency and low variation (jitter), make it one of the mostI

'Ichallenging net applications.

I P Internet 2 -the driving force behind Tele-immersion'

It is the next generation internet. Tele-immersion wasI conceived as ideal application for driving network engineering research. Internet2 is a

consortium consisting of the US government, industries and around 20 0 universities

: and colleges.

It has high bandwidth and speed. It enables revolutionary

internet applications.

i-. Need for speed:

If a computer network can support tele-immersion, it can

probably support any other application. This is because tele-immersion demands as

little delay as possible from flows of information (and as little inconsistency in delay),

in addition to the more common demands for very large and reliable flows.

-train to Network :

In tele-immersion not only participant's motion but also the

entire surface of each participant had to sent. So it strained a network very strongly.

Our demand for bandwidth varies with the scene and application; a more complex

scene requires more bandwidth.

i Network backbone:

A backbone is a network within a network that lets information//t

Itravel over exceptionally powerful, widely shared connections to go long distances

/ more quickly. Each of earlier net played a part in inspiring new applications for the

Dspt-of CSE


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TELE-IMMERSION

Internet, such as the World Wide Web. Another backbone research project, called

Abilene, began in 1998, and it was to serve a university consortium called Internet2.

Abilene now reache s more than 170 Am erican research

universities. If the only goal o f Internet2 were to offer a high level o f bandwidth (that

is, a large number of bits per second), then the mere existence of Abilene and related

resources be sufficient. But Internet2 research targeted additional goals, among them

the development of new protocols for handling applications that demand very high

.bandwidth and very low, controlled latencies (delays imposed by processing signals

and route).

COMPUTATIONAL NEEDS

Beyon d the scene-capture system, the principal com ponents

of a tele-immersion setup are the computers, the network services, the display and

interaction devices. Literally dozens of processors are currently needed at each site to

keep up with the dem ands of tele-immersion. R oughly speaking, a cluster of eight two-

gigahertz Pentium processors with shared memory should be able to process a triowithin a sea of cameras in approximately real time. Such processor clusters should be

available in the later year.

Bandwidth is a crucial concern. Our demand for bandwidth

varies with the scene and application; a more complex scene requires more bandwidth.

We can assume that much of the scene, particularly the background walls and such, is

unchanging and does not need to be resent with each frame.

Conveying a single person at a desk, without thesurrounding room, at a slow frame rate of about two frames per second has proved to

require around 20 megabits per second but with up to 80-megabit-per-second peaks.

With time, however, that number will fall as better compression techniques become

established. Each site must receive the streams from all the others, soin a three-way

conversation the bandw idth requirement m ust be m ultiplied accordingly.

Dept.of CSE 9 SN(;CE.Kolenchery


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'IELE-IMMERSION

TELE CUBICLE

The tele-cubiclc represents the next gerieration iriimcrsive

interface. It can also be seen as a subset of all possible imrricrsive interfaces. An oftice

appears as one quadrant in a larger shared virtual office space. 'l'he canvases onto which

the imagery can be displayed are a stero-immersive desk surface as \veil as at least two

stereo. Such a system represents the unitication of Virtual Reality and vidcoconfcrencing.

and it provides an opportunity for the full integration of VR into the workflow. Physical

and virti~al nvironments appear united for both input and display. 'l'liis combination, we

bclievc, offers a new paradigm for human communications and collaboration .

2 obliquefmnt stereo _ A

Tele cubicle which consists of two w-all surfaces and a desk surfacc wl~icli prqjects 3 D

images.

It consists of a stereo irnniersivc desk surface and two

btereo-imrncrsive wall surfaces. These three display surfaces join to form a corner desk

mit . The \.\ialls appear as windows to the otlier users' environment while thc desks join

3cpt.of CSE


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together to form a virtual conference tablc in the centre. This will a l l o ~ hc realistic

inclusion of tele-immersion into the work environment. as it \vill takc up the usualamount of desk space.

'Today's tcle-immersion conibincs the superior displa) of

CAVE and ImmersaDesk display systcnis ~ i t h dvaliced ~letuorl< apabilities .The

CAVE (Cave Automatic Virtual Environment) is a ~nulti-display virti~al eality device

comprised of three projection screcn,two "walls" and a *'floor" ~\hicI=i projects rcal-time

images in response to the user's eye and/or head movements. I'o ensure thc qualit) of the

picture and timeliness of response, the CAVE must be controllcd by a po~zerfi~l achine.

or supcrcompuier. I n some cases, CAVE proccssing units contain lip to sixteen

processors .CAVE is an example of 3D disply system which i~nplements ' l'elecubicle ".

TELE IMME RSION STIJDIO

It's a room uith all array of vidco cameras to provide

multiple viewpoints and a group of computers to process tlie digitized images. Tlie

people. who appeared as 3-D images. cberc tracked wit11 an array of eight ordinar) video

cameras whilc three other video cameras captured real liglit patterns in room lo calculate

distances. 'This enables tlie proper depth to be recreated on the 3 - D space.

In a remote location, a vicwcr sits In front of a screen.

\\earin:: polarized glasses like those used for 3-T) movics. The screen shows uhat or c ~ h o

's i n front of the arra) of video cameras. If the obserker rnovzd his or her head to the

'zfr. he/slie could see the corresponding images rliat \\auld bc seal if she were actually in

:5e rooni u ith the person on tlie screen.

I12~1 .~ffSE 1 1 SN(iC't:.Kolenchery


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APPLICATIONS

I) collaborative Engineering WorksTeams of engineers might collaborate at great distances on

computerized designs for new machines that can be tinkered with as through they were

real models on a shared workbench. Archaeologists from around the world might

experience being present during a crucial dig. Rarefied experts in building inspection or

engine repair might be able to visit locations without losing time to air travel.

2) Video Conferencing

Although few would claim that tele-immersion will be

absolutely as good as "being there" in the near term, it might be good enough for

business meetings, professional consultations, training sessions, trade show exhibits

and the like. Business travel might be replaced to a significant degree by tele-

immersion in I0 years. This is not only because tele-immersion will become better and

cheaper but because air travel will face limits to growth because of safety, land use and

environmental concerns.

3) Irnrnersive Electronic Book

Applications of tele-immersion will include immersive

.electronic books that in effect blend a "time machine" with 3D hypermedia, to add an

additional important dimension, that of being able to record experiences in witch a

viewer, immersed in the 3D reconstruction, can literally walk through the scene orj1 move backward and forward in time. While there are many potential application areasI'

for such novel technologies (e.g., design and virtual prototyping, maintenance and

repair, paleontological and archaeological reconstruction), the focus here will be on a

socially important and technologically challenging driving application, teaching

surgical management of difficult, potentially lethal, injuries.

4) Collaborative mechanical CAD

A group of designers will be able to collaborate from

remote sites in an interactive design process. They will be able to manipulate a virtual

'model starting from the conceptual design, review and discuss the design at each stage,

perform desired evaluation and simulation, and even finish off the cycle with the

production of the concrete part on the milling machines.

Dept-of CSE 13 SN(;GE.Kolenchery


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5) Entertainment

Tele-inimersive holographic environments have a number

of applications. Imagine a video game free of joysticks. i n which you become a

participant in the game, fighting rnonsters or scoring touchdowns.

6) Live chat

Instead oftraveling hundreds of miles to visit your relatives

during the holidays, you can simply call thein up and join them in a shared holographic

room.

7) Medicine

Tele immersion can be of immense use to the field of

medicine. The way medicine is taught and practiced has always been very hands-on. I t is

impossible to treat a patient over the phone or give i~lstructions for a tilmour to be

removed without physically being there. With the help of tele-immersion. 3 D surgical

learning for virtual operations is now in place and, i u the future. the hope is to he able to

carry out real surgery on real patients. A geographically distanced surgeon could be tele-immersed into an operation theatre to perform an operation. This could potentially be

lifesaving if the patient is in need of' special care (either a technique or a piece of

equipment), which is not available at that particular location.Tele-immersion 'will give

surgeons.the ability to superimpose anato~nic mages right on their patients \while they are

being operated on'.

8) Uses in education

I11 education, tele-immersion can be used to bring together

students at remote sites in a single environment. Kelationships among educational

institutions could improve tremendously in the future with the use of tele-immersion.

Already, the academic world is sharing information on research and development to

I better the end results. Doctors and soldiers could use tele-immersion to train in ai

simulated environment. This will be a distinct advantage in surgical training. While it

will not replace the hands-on training, this technology will give surgeons a chance toP learn complex situations before they treat their patients. With teleinlmersion in schools.

Dept.of CSE 13 SNGCE.Kolencher1


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students could have access to data or control a telescope from a reniote location. or meet

with students from other countries by projecting themsclvcs into a foreign space.

Internet2 will provide access to digital librarics and virtual labs, opening up the lil!es of

communication for students. Tele-immersion will bring to the111 places, equipnient and

situations earlier not available, helping tl-iem expcrience what they could have on11

watched. read or heard about earlier.

9) Future office

In years to come, instead of asking for a colleagi~e on the

phone you will find it easier to instruct your computer to find him or her. Once yo11 do

that, you'll probably see a flicker on one ol' your office walls arid lind that your

colleague, who's physically present in another city, is sitting right across you as if' he or

she is right there. The person at the other end will experience the sanlc inimersivc

connection. With tele-immersion bringing t ~ o r more distant people together in a single.

si~nulatcd ffice setting, business travel will become quite redundant.

g Other applications

Building inspectors could tour structures without leaving

their deslts. Automobile desigmers from different continents coi~ld meet to develop the

next generation of vehicles. In the entertainment industry, ballroo~n dancers could train

together from separate physical spaces. lnstead of cornmutirig to ~ o r k or a board

meeting, businesspersons could attend i t by projecting Lhemselves into the conferelice

room. The list of' applications is large atid varied. and one thing is crystal clear thistechnology \ w i l l signiiicantly affect the educational, scientific and nledical sectors.


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CHALLENGES OF TELE-IMMERSION

Tele-immersioii has emerged as a high-end driver for tlle Quality of Servicc (QoS),

bandwidth. and reservation efforts envisioned by the NGI and Internet2 leadership.

From a networking perspective, tele-immcrsion is a very challenging technology for

several reasons.

The networks must be in place and tuned to support high-bandwidth

applications.

Low latency, needed for 2-way collaboration, is hard to specify and guarantee

given current middleware.

The speed of light in fiber itself is a limiting factor over transcontinental and

transoceanic distances.

Multicast, unicast, reliable and unreliable data transmissions (called "flows")

need to be provided for and managed by the networks and the operating systems

of supercomputer-class workstations.

. Real-time considerations for video and audio reconstruction ("streaming") are

I critical to achieving the feel of telepresence, whether synchronous or recordedI and played backs1 The computers, too, are bandwidth limited with regard to handling very large11;11

data for collaboration~

Simulation and data mining are open-ended in computational and bandwidth

needs-there will never be quite enough computing and bitslsecond to fullyanalyze, and simulate reality for scientific purposes.

In Layman's language the realization of tele-imniersion is impossible today due

to

1. The non-availability of high speed networks

2. The non-availability of supercomputers

3. Large network bandwidth requirement reasons


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SOLUTION

The ilrst two basic problc~ns can be overcome Iwhen Internet-2 will come into picture later and third problem can be overcorue by the Ifast development of image compression techniques.

ABOUT INTERNE T3

Internet2 is not a separate physical ne~work and will not replace the current IInternet. It is not for profit consortium consisting of 200 I J S universities. 1Industries and is directly under the control of US govt..

Internet2 is for developing and deploying advanced network applica~ions and Itechnology, accelerating the creation of tomorroc\rfs nternet.

Jnternet2 enables completely new applications such as digital libraries. cirtual

laboratories, distance-independent learning and tele-immersion.

A key goal of this effort is to accelerate the diffusion of advanced Internet

technology, in particular into the commercial sector.

Internet2 is the second generation internet, helps to develop

advanced network applications and technologies for research and higher education, by

recreating the partnerships among academia, industry, and government.

Another backbone research project, called Abilene, begun

in 1998, and it was to serve Internet2. Abilene now reaches more than 170 American

research universities. Internet2 research targeted in the development of new protocols for

handling applications that demand very high bandwidth and very low, controlled

Iatencies (delay is reduced by processing signals along their travel through the network).

We need a po\verful network with high speed and high

bandwidth to transfer the large a~nounts of data that tele-immersion will

psoduce.lnternet2 will replace the current Internet infrastructure. l'his new network will

hale a higher bandwidth and speeds that are 1000 times faster than today's Intenlet. 1 his

. .hgh-bandwidth, high-speed provided by Internet2 is sui'licient to transfkr the largeamounts of data that tele-immersion will produce.

I$c;.r.of CSE 16 SNGCE.liolenchery


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TELE-IMMERSION

Internet 2 had a peculiar problem : no existing applications

that requires the high levcl of performance provided by internet 2 except teleinimersion

Desktop supercomputers

The Grid will use distributed cotnputiug. There are not

enough supercomputers to deal with the enorlnous amounts of data that n i l l rush through

the Net in the future. As a solution, new networks will connect their PCs so they can

share processing power and hard disk space. 'l'hey nil1 be locked in toa

grid-effectivelyci-eating one supercomputer. About a dozen American universities are doing research 011

various aspects of immersive technologies, including USC, the University of North

Carolina. the University of Pennsylvania and Brown University Mainly two institutions

called P E N N and UNC (University of north Carolina) are doing researches in tele

immersion.

Bandwidth issues

Network bandwidth required to make tclc-irnniersio~~ ork

is one of the main concerns of this new technology. It is estimated that a s much as 1.2

gigabits per second will be needed for future high-quality effects. This is much higher

than the average home connection bandwidth. l'he exact amount of bandwidth needed for

each scene depends on the complexity of the background. With time, the number of

megabits used for transmitting a scene will rcducc as advanced compsession techniques

are established. Initially, bandwidth-intensive applications will have to be limited to the

larger organizations that can afford high c,onnection speeds


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'I'ELE-I MMERSlON

CURRENT DEVELOPMENTS

Haptic sensors: Miniaturized forceltorque sensors

There is an increasing need for measuring forces acting

between human hands and the environment. External finger forces are measured by

placing force sensing pads at the fingertips. A wide variety of such pads have been

developed in the past for applications in robotics and medicine, using resistive,

11 capacitive, piezoelectric, or optical elements to detect force. A critical problem with these11

I force sensors is that they are often bulky and inevitably deteriorate the human's haptic

sense, since the fingers cannot directly touch the environment surface.1~

I Recently, much research has focused on rcducing this

problem by inventing thinner and morc tlexiblc force-sensing pads. a new approach to the

detection of finger forces is presented i n order to completely climinate any irnpedinient to

the natural haptic sense and hence thc name 'haptic sensors'. (Haptic mcans that '

relating to or based on the sense of touch ' ). An optical sensor mounted on the fingernailI detects the force. This allows the human to touch the environment with barc fingers andI

perform fine, delicate tasks using the full range of haptic sense. Miniaturized optical

components and circuitry allow the sensor to be disguised as a decorative fiiigernail

covering.

.l-laptic sensor is a new type of touch sensor for detecting

contact pressure at human fingertips. Ijence the sensor is rnounted on the fingernail rather

:ban on the fingertip. Specifically, the fingernail is instrumented with miniature light

emitting diodes (LEDs) and photo detectors in order to measure changes in the reflection

intensity whcn the fingertip is pressed against a surface. I'hc changes i n intensit), are then

~ s e do determine changes in the blood volume under the fingernail. a tcchniquc termed

--reflectance photoplethysmography." A ho~nodynalnic model is used to investigate the

d~namics f the blood volume at two locations under the fingernail.A

miniaturizedprototype nail sensor is de-signed. built, and tested. 'T'he theoretical analysis is verified

through experiment and simulation.


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TELE-IMMERSION

Fig :Implementation of tingernail touch sensors

Figure shows the implementation of fingernail touch sensors. For the prototjrpe s h o ~ nherc. two photodiode arrays of dimension4 mm 1 mm are attached end to cnd on the

bottom sidc. Up to 8 of the 32 total photodiodcs canbe m~iredup at once, rcsulting i n up

to cight sensing locations along the Icn@h of thc fingernail. IJp to three LEDs of

dimension 0.25 mm 0.25 min can be placedi n flexible locations beside the photodiode

arrays.

Haptic sensors would allow people to touch prc),jectionsas

if they were real. A 3D sensor and supporting software has been developed and patented

that ena bles the real-time visualization of the haptic sense of pressure. Haptic sen sors can

be used in tele immersion systems to sense the pressure and reconstruct the feeling of

touch in com bination with other devices

Dept.of CSE 19 SNC;CE.Kolencliery


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CONCLUSION

Tele-immersion is a fast developing technologq and it isgoing to benefit the common man once Internet-2 comes into picture. i t is of i~nmense

use in thc field of

J MedicineJ It helps in reducing business travel

J Education and numerous other fields

Tele immersion is a dynamic concept, which will

transform the way humans, interact with each other and the world in general.Tele-lmmersion is a technology that is certainly going to

bring a new revolution in the world and let us all hope that this technolog) reaches the

world i n its f i l l 1 flow as quickly as possible.

Dept.of C SE


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FUTURE SCOPE

The tele-immersion system of 20 10 would ideally:

Support one or more flat panels/projectors with ultra-high color resolution (say

5000x5000)

Be stereo capable without special glasses

Have several built-in micro-cameras and microphones

Have tether-less, low-latency, high-accuracy tracking

Network to teraflop computing via multi-gigabit optical switches with low

latency

Have exquisite directional sound capability

Be available in a range of compatible hardware and software configurations

Have gaze-directed or gesture-directed variable resolution and quality of

rendering

Incorporate AI-based predictive models to compensate for latency and anticipate

user transitions

Use a range of sophisticated haptic devices to couple to human movement and

touch

Accommodate disabled and fatigued users in the spirit of the Every Citizen

Interface to the NTlI (National Telc- Immersion Initiative ).

Dept.of CSE 2 1 SNC;Ck~.I.;olenchcry


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TELE-!MM ERSION

Dept.of CS E 22 SNGCE.Kolcr.z:- L -

Documents

Sathu G Rajan Nov. 2006