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INTRODUCTION
It is 2010 and you have a very important meeting with your business associates in Chennai. However you have visitors from Japan coming for a mega business deal the same day. Is there any technology by which you can deal with both of them The answer is yes and the name of that technology is Tele-Immersion. Tele-Immersion is a technology by which youâ„¢ll interact instantly with your friend on the other side of the globe through a simulated holographic environment. This technology, which will come along with Internet2, will change the way we work, study and get medical help. It will change the way we live. Tele-Immersion (TI) is defined as the integration of audio and video conferencing, via image-based modeling, with collaborative virtual reality (CVR) in the context of data-mining & significant computation. The 3D effect behind the tele-immersion makes it feel like the real thing. The ultimate goal of TI is not merely to reproduce a real face-to-face meeting in every detail, but to provide the next generation interface for collaborators, world-wide, to work together in a virtual environment that is seamlessly enhanced by computation and large databases. When participants are tele-immersed, they are able to see and interact with each other and objects in a shared virtual environment.
Tele-immersion can be of immense use in medical industry and it also finds its application in the field of education
CAVE
THE HISTORY
It was in 1965 that, Ivan Sutherland, proposed the concept of the ËœUltimate Displayâ„¢. It described a graphics display that would allow the user to experience a completely computer-rendered environment. The term Tele-immersion was 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, and education. In 1998 Abilene, a backbone research project was launched and now serves as the base for Internet-2 research. Tele-immersion is the application that will drive forward the research of Internet-2.

There are several groups working together on National Tele-Immersion Initiative(NTII) to make this wonderful technology available to common man.


FIRST FEEL OF TELE-IMMERSION
A swift investigation revealed that three researchers, led by UNC computer Scientists Henry Fuchs and Greg Welch, in May 2000 opened a pair of portals connecting Chapel Hill with Philadelphia and New York. Through these portals, they could peer into the offices of colleagues hundreds of miles away, in life-sized three dimensions and real time. It was as if they had teleported distant chunks of space into their laboratory. The experiment was the first demonstration of Tele-immersion, which could radically change the way we communicate over long distances. Tele-immersion will allow people in different parts of the world to submerge themselves in one another's presence and feel as if they are sharing the same physical space. It's the real- world answer to the StarTrek Holodeck, the projection chamber on the Starship Enterprise where crew members interact with projected images as if they were real.
May's experiment was the culmination of three years' work by the National Tele-Immersion Initiative (NTII), a project led by virtual pioneer Jaron Lanier. The test linked three of the members of the group:UNC Chapel Hill, the University of Pennsylvania in Philadelphia, non-profit organisation called Advanced Network and Services in Armonk, New York, where Lanier is chief scientist.
At Chapel Hill, there were two large screens, hung at right angles above desk, plus projection cameras and head tracking gear. The screens were flat and solid, but once the demo was up and running they looked more like windows. Through the left-hand screen, Welch could see colleagues in Philadelphia as if they were sitting across the desk from him. The right-hand screen did the same for Armonk. When Welch changed point of view, the images shifted in a natural way. If he leaned in, images got larger, if he leaned out they got smaller. He could even turn his neck to look round the people.
To make it work, both target sites were kitted out with arrays of digital cameras to capture images and laser rangefinders to gather positional information. Computers then converted the images into 3D geometrical information and transmitted it to Chapel Hill via Internet2. There, computers reconstructed the images and projectors beamed them onto screens.
The images were split and polarised to create a slightly different image to each eye, much like an old-fashioned 3D movie. Welch wore glasses differently oriented polarising lenses so his left eye saw one image right eye the other, which his brain combined to produce 3D images.
A head-mounted tracker followed Welch's movements and changed the images on the screens accordingly. Like the first transcontinental phone call, the quality was scratchy, also jerky, updating around three times a second rather than 10, the minimum speed needed to capture the full range of facial expressions. It only worked one-way: the people in Armonk and Philadelphia couldn't see Chapel Hill.
All this may sound like conventional videoconferencing. But Tele-immersion is much, much more. Where videoconferencing delivers flat images to a screen, Tele-immersion recreates an entire remote environment.

SCIENCE OF TELE-IMMERSION
Tele-Immersion has an environment called TIDE. TIDE stands for Tele-Immersive Data exploration Environment. The goal of TIDE is to employ Tele-Immersion techniques to create a persistent environment in which collaborators around the world can engage in long-term exploration and analysis of massive scientific data-sets. When participants are tele-immersed, they are able to see and interact with each other and objects in a shared virtual environment. Their presence will be depicted by life-like representations of themselves (avatars) that are generated by real-time, image capture, and modeling techniques. The environment will persist even when all the participants have left it. The environment may autonomously control supercomputing computations, query databases and gather the results for visualization when the participants return. Participants may even leave messages for their colleagues who can then replay them as a full audio, video and gestural stream.
All users are separated by hundreds of miles but appear collocated able to see each other as either a video image or as a simplified virtual representation (commonly known as an avatar). Each avatar has arms and hands so that they may convey natural gesture such as pointing at areas of interest in the visualization. Digital audio is streamed between the sites to allow them to speak to each other.
TIDE will engage users in CAVEs, ImmersaDesks and desktop workstations around the world connected by the Science and Technology Transit Access Point (STARTAP) - a system of high speed national and international networks. TIDE has three main parts:
TELE-IMMERSION SERVER (TIS)
TELE-IMMERSION CLIENT (TIC)
REMOTE DATA AND COMPUTATIONAL SERVICES




TELE-IMMERSION SERVER:
The Tele-Immersion Serverâ„¢s primary responsibility is to create a persistent entry point for the TICs. That is, when a client is connected to the TIS, a user can work synchronously or asynchronously with other users. The environment will persist even when all participants have left it. The server also maintains the consistent state that is shared across all participating TICs. Finally the TIS stores the data subsets that are extracted from the external data sources. The data subsets may consist of raw and derived data sets, three dimensional models or images.
TELE-IMMERSION CLIENT
The Tele-Immersion Client (TIC) consists of the VR display device (either CAVE, ImmersaDesk, etc) and the software tools necessary to allow human-in-the loop computational steering, retrieval, visualization, and annotation of the data. The TIC also provides the basic capabilities for streaming audio and video, and for rendering avatars to allow participants to communicate effectively with one another while they are immersed in the environment. These capabilities come as part of EVLâ„¢s Tele-Immersion software framework called CAVERNsoft.


REMOTE DATA & COMPUTATION SERVICES
Remote Data and Computation Services refer to external databases and/or simulations/compute-intensive tasks running on supercomputers or compute clusters that may be called upon to participate in a TIDE work session.
The databases may house raw data, or data generated as a result ofcomputations. In most cases the data-sets contain too many dimensions and are much too large to visualize entirely. However data mining may be employed to clean the data, to detect specific features in the data, or to extract trends from the data. In some cases as the data mining processes may generate models of the data, the models can be used to make predictions on missing data points. Furthermore the models can be used to determine which attributes in a multidimensional data-set are the most significant. This is particularly valuable for visualization because the ability to fill missing data points means a more accurate estimate of the missing data can be made than by simple graphical interpolation. In addition by being able to isolate the most significant attributes, a viewer can prioritize the attributes that they assign to visual features (such as hue, intensity, shape etc) in the visualization. For example Nakayama and Silverman have shown that stereoscopic depth is the most powerful, pre-attentively detected visual feature as compared to other features such as intensity and hue (the features most commonly used in scientific visualizations.) This is a particularly interesting finding for VR because the medium in which VR resides is inherently stereoscopic. In TIDE the approach taken is to employ data mining algorithms where appropriate as a means to partition space non-isotropically; to exclude attributes with low significance; to smart average attribute values to summarize a number of attributes into a single attribute (as a means to reduce dimensionality); and to decimate the data based on the limits of the VR visualization system.
Initially many of these processes will be controlled on desktop interfaces of PSEs and the resulting decimated data is distributed amongst the collaborators via the Tele-Immersion server. However over time we will gradually allow an increasing number of these functions to be controlled directly from within the Tele-Immersion environment using three-dimensional interfaces.


VIRTUAL REALITY (VR) DISPLAY DEVICES
As stated earlier VR display devices are mainly four in number. They are listed below
CAVE
Immersa Desk
Desktop workstation
Desktop Workstation
CAVE
The CAVE virtual reality system is a 10 foot-cubed room that is projected with stereoscopic images creating the illusion that objects appear to co-exist with the user in the room. The CAVE„¢ is a multi-person, room-sized, high-resolution, 3D video and audio environment. Graphics are projected in stereo onto three walls and the floor, and viewed with stereo glasses. As a viewer wearing a location sensor moves within its display boundaries, thecorrect perspective and stereo projections of the environment are constantly updated, so the image moves with and surrounds the viewer to achieve immersion.

Figure of CAVE

IMMERSA DESK
The ImmersaDesk„¢ is a drafting-table format version of the CAVE. When folded up, it fits through a standard institutional door, and deploys into a 6™ x 8™ footprint. It requires a single graphics engine of the SGI Onyx or Octane class, one projector, and no architectural modifications to the working space. The Immersa Desk is software compatible with the CAVE library.

figure
DESKTOP WORKSTATION
The desktop workstationdisplays a data-flow model that can be used to construct the visualization that is shared between all three display devices. The participants in the VR displays can use three-dimensional tools to directly manipulate the visualization.
For example in the CAVE a user is changing the isosurface value in the data-set. These changes are automatically propagated to all the other visualization displays. In the meantime the ImmersaDesk user, noticing an anomaly in the data-set, inserts an annotation in the data-set as a reminder to return to more closely examine the region. Closer examination of the region is achieved by instructing a remote rendering server consisting of multiple giga-bytes of RAM and terabytes of disk space, to render the images in full detail as a stereoscopic animation sequence. These animations will take some time to generate and so the users continue to examine other aspects of the dataset. Eventually the rendering is complete and the remote server streams the animation to each of the visualization clients for viewing.
INFINITY WALL
The Infinity Wall is derivative of the Power- Wall, a research effort of Paul Woodward at the University of Minnesota. The PowerWall achieves very high display resolution through parallelism, building up a single image from an array of display panels projected from the rear onto a single screen. High-speed playback of previously rendered images is possible by attaching extremely fast disk subsystems, accessed in parallel, to an Onyx. The Infinity Wall is a simpler Power Wall that has tracking and stereo; it is CAVE library compatible.

figure
APPLICATIONS OF TELE-IMMERSION
The list of applications of tele-immersion is very large. Some of them are:
o Interacting with friends miles away in a simulated holographic environment.
o Tele-immersion can be of immense use in medical industry.
o Tele-immersion also finds its application in the field of education.
A large set of applications can be managed, depending on the position of infinity wall:
1. Full scaled model preview in industrial application (aircrafts, cars, ¦) when all three modules are lined up (180o)
2. Flight simulation scenarios visualization when side-modules are in 135° layout;
3. Immersive simulations when side-modules are in the room setup (90o)

MEDICAL APPLICATIONS


3D surgical learning for virtual operations is possible using this technology.
In future real surgery can be carried out on real patients.
It could be life saving if the patient is in need of special care.
It gives surgeons the ability to superimpose anatomic images right on their patients while they are being operated on. Surgeons get a chance to learn complex situations before they actually treat their patients.

USES IN EDUCATION
It can be used to bring together students at remote sites in a single environment. With tele-immersion students can access data from remote locations. Internet2will provide access to digital libraries and virtual labs.
Exchange of culture is possible without travel.

figure

FUTURE OFFICE


CHALLENGES OF TELE-IMMERSION
Tele-immersion has emerged as a high-end driver for the Quality of Service (QoS), bandwidth, and reservation efforts envisioned by the NGI and Internet2 leadership. From a networking perspective, tele-immersion 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 critical to achieving the feel of telepresence, whether synchronous or recorded and played back
¢ The computers, too, are bandwidth limited with regard to handling very large data for collaboration
¢ Simulation and data mining are open-ended in computational and bandwidth needs”there will never be quite enough computing and bits/second to fully analyze, and simulate reality for scientific purposes.

In Laymanâ„¢s language the realization of tele-immersion is impossible today due to
1. The non-availability of high speed networks
2. The non-availability of supercomputers
3. Large network bandwidth requirements

SOLUTION
The first two basic problems can be overcome when Internet-2 will come into picture later and third problem can be overcome by the fast development of image compression techniques.
ABOUT INTERNET-2

¢ Internet2 is not a separate physical network and will not replace the current Internet. It is not for profit consortium consisting of 200 US universities, Industries and is directly under the control of US govt..
¢ Internet2 is for developing and deploying advanced network applications and technology, accelerating the creation of tomorrow's Internet.
¢ Internet2 enables completely new applications such as digital libraries, virtual 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.
FUTURE DEVELOPMENTS
The tele-immersion system of 2010 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 NII [2]
CONCLUSION
Tele-Immersion is a fast developing technology and it is going to benefit the common man once Internet-2 comes into picture. It is of immense use in the field of
Medicine
Education and numerous other fields
It also helps in reducing business travel.
Tele-Immersion is a technology that is certainly going to bring a new revolution in the world and let us all hope that this technology reaches the world in its full flow as quickly as possible.

REFERENCES
1. electronicsforu .com
2. ieee.com
3. NTII.com
4. advancedorg.tele-immersion.com
5. newscientist.com
6. IT magazine August 2003

APPENDIX



The columns represent flow-type attributes:
¢ Latency is the sum of all delays in the system, from the speed of light in fiber, to operating system overhead, to tracker settling time and screen refresh
¢ Bandwidth is the bits/second the system can transmit
¢ Reliable flows are verified and retransmitted if bad
¢ Multicast flows go to more than one site at once
¢ Security involves encryption overhead that may or may not be warranted or legal
¢ Streaming data is a constant flow of information over time, as with video, audio and tracking
¢ Dynamic QoS can provide ways to service bursty high-bandwidth needs on request
The rows indicate the data flow types:
¢ Control information consists of data that is used to manage the tele-immersion session, to authenticate users or processes, to launch processes, to control the display or tracking systems, and to communicate out of band between the world servers and VR systems.
¢ Text provides simple communications capability within collaborative sessions for simple note taking and passing. Text can also command Unix processes driving the environments.
¢ Audio gives ambient auditory cues, allows voice communications among users, and is used to issue commands via voice recognition and speech synthesis. A typical application may use multiple audio streams.
¢ Video can allow teleconferencing or remote monitoring displayed within the virtual world. Synthetic 2D animated bitmaps in video format have application as well.
¢ Tracking is achieved with location and orientation sensors, and captures the position and orientation of the user. Typically this data is streamed to the computer responsible for computing the perspective of the scene. Tele-immersion requires tracking data to be shared among sites. Most VR systems only head and hand track; future systems will have many more sensors to track more complex posture and body motions.
¢ Database is the heart of a tele-immersion application world. The database contains the graphical models of virtual scenes, objects, and data, and since the database is used to provide the models that are rendered, it must be maintained in a coherent state across multiple sites. Databases might be as simple as shared VRML files or as complex as multi-terabyte scientific datasets, VR extensions of video serving, or even Virtual Director recorded sessions. (Virtual Director is a joint EVL/NCSA development project. [29])
¢ Simulation provides the basis for dynamics behaviors, like responding to the users™ actions. Small-scale simulations often run on the computer also generating the VR experience, but frequently the simulation will need a dedicated supercomputer. [28] User input is captured and transmitted to the simulation via the network and the simulation will generate an update, which is then propagated to each user site for local

ACKNOWLEDGEMENT
I express my sincere gratitude to Dr.Nambissan, Prof. & Head, Department of Electrical and Electronics Engineering, MES College of Engineering, Kuttippuram, for his sincere and dedicated cooperation and encouragement.
I would also like to thank my seminar guide Mrs. Haseena P.Y. Lecturer, Department of EEE, MES College of Engg., Kuttippuram, for her invaluable advice and wholehearted cooperation without which this seminar would not have seen the light of day.
Gracious gratitude to all the faculty of the department of EEE & friends for their valuable advice and encouragement.

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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 Internet21t 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 looking, 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 virtual ; 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.
INTRODUCTION
Tele-immersion, a new medium for human interaction enabled by digital technologies, approximates the illusion that a user is in the same physical space as other people, even through the other participants might in fact be 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 the participants, however distant, can share and explore a life-size space.
Beyond improving on videoconferencing, tele-immersion was conceived as an ideal application for driving network-engineering research, specifically for Internet^, the primary research consortium for advanced network studies in the U.S. 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.
Tele-immersion can be of immense use in medical industry and it also finds its application in the field of education
THE HISTORY
It was in 1965 that, Ivan Sutherland, proposed the concept 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 was 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, and education. In 1998 Abilene, a backbone research project was launched and now serves as the base for Internet-2 research. Tele-immersion is the application that will drive forward, the research of Internet-2.
WHAT IS TELE- IMMERSION
Tele-immersion enables users at geographically distributed sites to collaborate in real time in a shared, simulated, hybrid environment as if they were in the same physical room. It is the ultimate synthesis of media technologies:
¦S 3D environment scanning.
¦S Projective and display technologies.
¦S Tracking technologies.
S Audio technologies.
S Powerful networking.
The considerable requirements for tele-immersion 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 driver for the research agendas of the Intern et2 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.
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 for 3D environment scanning method is to be used. It is by using multiple cameras for producing two separate images for each of eyes. 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 be in constant motion. Tele-immersion demands that each scene be sensed in a manner that is not biased toward any particular viewpoint (a camera, in contrast, is locked into portraying a scene from its own position). Each place, and the people and things in it, 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 as the "sea of cameras" approach, in which the viewpoints of many cameras are compared. In typical scenes in a human environment, there will tend to be visual 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, algorithms can 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 mounted on a geodesic dome. Because it was not a real - time device, it could not 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 - reality applications was 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. A person 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 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 shown promise for overcoming this obstacle, called " imperceptible structured light or ISL. Conventional light bulbs flicker 50 or 60 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, carefully synchronized cameras. These patterns fill in voids such as white wall with imposed 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
Dept-ofCSE
4
SNGCE.KoIencfe"
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 future 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 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.
RECONSTRUCTION IN A HOLOGRAPHIC ENVIRONMENT
; The process of reconstruction of image occurs in a
holographic environment. At the transmitting end. the 3d image scanned is generated j using two techniques. The reconstruction process is different for shared table and ic3d I approach.
r Shared Table Approach
!; Here, the depth ofthe 3d image is calculated using 3d wire
j frames, this technique uses various camera views and complex image analysis algorithms :, to calculate the depth.
Assuming that the geometrical parameters of the multi-j view capture device, the virtual scene and the virtual camera are well fitted to each other, j; it is ensured that the scene is viewed in the right perspective view, even while changing ii the viewing position.
i
r Ic3d(incomplete 3d) Approach
In this case, a common texture surface is extracted from the available camera views and the depth information is coded in an associated disparity map. This representation can be encoded into a mpeg-4 video object, which is then transmitted.
The decoded disparities are scaled according to the user's 3d viewpoint in the virtual scene, and a disparity-controlled projection is carried out. The 3d perspective of the person changes with the movement ofthe virtual camera.
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 camera, 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 camera is moved with the head.
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 curved and special projection cameras are to be used.
TRACKING TECHNOLOGIES
It is great necessity that each of the objects in the immersive environment be tracked so that we get a real world experience. This is done by tracking the movement of the user and adjusting the camera 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, unencumbered tracking of a user's head and hands over a room sized working area has been an elusive goal in modern technology and the weak page link in most virtual reality systems. Currant commercial offerings based on magnetic technologies perform poorly around such ubiquitous, magnetically noisy computer components as CRTs, while optical-based products have a very small working volume and illuminated beacon targets (LEDs). Lack of an effective tracker has crippled a host of augmented reality applications in which the user's views of the local surroundings are augmented by synthetic data (e.g., location of a tumor in the patient's brain or the removal path of a part from within a complicated piece of machinery).
MOVING SCULPTURES
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 the participants, however distant, can share and explore a life size space.
AUDIO TECHNOLOGIES
For true immersive effect the audio system has to be extended to another dimension, i.e., a 3D 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 most challenging net applications.
> Internet 2 -the driving force behind Tele-immersion
It is the next generation internet. Tele-immersion was conceived as ideal application for driving network engineering research. Internets is a consortium consisting of the US government, industries and around 200 universities and colleges.
It has high bandwidth and speed. It enables revolutionary
internet applications.
> 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.
> Strain 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.
> Network backbone:
A backbone is a network within a network that lets information travel 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
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 reaches more than 170 American research universities. If the only goal of Internet^ were to offer a high level of 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
Beyond the scene-capture system, the principal components 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 demands of tele-immersion. Roughly speaking, a cluster of eight two-gigahertz Pentium processors with shared memory should be able to process a trio within 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 the surrounding 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, so in a three-way conversation the bandwidth requirement must be multiplied accordingly.
TELE CUBICLE
The tele-cubicle represents the next generation immersive interface. It can also be seen as a subset of all possible immersive interfaces. An office appears as one quadrant in a larger shared virtual office space. The canvases onto which
1
j the imagery can be displayed are a stero-immersive desk surface as well as at least two I stereo. Such a system represents the unification of Virtual Reality and videoconferencing, 1 and it provides an opportunity for the full integration of VR into the workflow. Physical and virtual environments appear united for both input and display. This combination, we believe, offers a new paradigm for human communications and collaboration .
Tele cubicle which consists of two wall surfaces and a desk surface which projects 3D images.
It consists of a stereo immersive desk surface and two stereo-immersive wall surfaces. These three display surfaces join to form a corner desk unit. The walls appear as windows to the other users' environment while the desks join together to form a virtual conference table in the centre. This will allow the realistic inclusion of tele-immersion into the work environment, as it will take up the usual amount of desk space.
Today's tele-immersion combines the superior display of CAVE and ImmersaDesk display systems with advanced network capabilities .The CAVE (Cave Automatic Virtual Environment) is a multi-display virtual reality device comprised of three projection screen,two "walls" and a "floor" which projects real-time images in response to the user's eye and/or head movements. To ensure the quality ofthe
;! picture and timeliness of response, the CAVE must be controlled by a powerful machine.
!' or supercomputer. In some cases, CAVE processing units contain up to sixteen processors .CAVE is an example of 3D disply system which implements Telecubicle ". TELE IMMERSION STUDIO
It's a room with an array of video cameras to provide multiple viewpoints and a group of computers to process the digitized images. The people, who appeared as 3-D images, were tracked with an array of eight ordinary video cameras while three other video cameras captured real light patterns in room to calculate distances. This enables the proper depth to be recreated on the 3 - D space.
In a remote location, a viewer sits in front of a screen, wearing polarized glasses like those used for 3-D movies. The screen shows what or who is in front of the array of video cameras. If the observer moved his or her head to the 'eft. he/she could see the corresponding images that would be seen if she were actually in :he room with the person on the screen.
APPLICATIONS
1) Collaborative Engineering Works
Teams 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 10 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) Immersive 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 or move backward and forward in time. While there are many potential application areas 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.
5) Entertainment
Tele-immersive holographic environments have a number of applications. Imagine a video game free of joysticks, in which you become a participant in the game, fighting monsters or scoring touchdowns.
6) Live chat
Instead of traveling hundreds of miles to visit your relatives during the holidays, you can simply call them 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. It is impossible to treat a patient over the phone or give instructions for a tumour to be removed without physically being there. With the help of tele-immersion. 3D surgical learning for virtual operations is now in place and, in the future, the hope is to be 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 surgeonsthe ability to superimpose anatomic images right on their patients while they are being operated on'.
8) Uses in education
In education, tele-immersion can be used to bring together students at remote sites in a single environment. Relationships 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 better the end results. Doctors and soldiers could use tele-immersion to train in a 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 to |
I
learn complex situations before they treat their patients. With teleimmersion in schools, j
students could have access to data or control a telescope from a remote location, or meet with students from other countries by projecting themselves into a foreign space. Internet2 will provide access to digital libraries and virtual labs, opening up the lilies of communication for students. Tele-immersion will bring to them places, equipment and situations earlier not available, helping them experience what they could have only watched, read or heard about earlier.
9) Future office
In years to come, instead of asking for a colleague on the phone you will find it easier to instruct your computer to find him or her. Once you do that, you'll probably see a flicker on one of your office walls and find 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 same immersive connection. With tele-immersion bringing two or more distant people together in a single, simulated office setting, business travel will become quite redundant.
Other applications
Building inspectors could tour structures without leaving their desks. Automobile designers from different continents could meet to develop the next generation of vehicles. In the entertainment industry, ballroom dancers could train together from separate physical spaces. Instead of commuting to work for a board meeting, businesspersons could attend it by projecting themselves into the conference room. The list of applications is large and varied, and one thing is crystal clear this technology will significantly affect the educational, scientific and medical sectors.
CHALLENGES OF TELE-IMMERSION
Tele-immersion has emerged as a high-end driver for die Quality of Service (QoS), bandwidth, and reservation efforts envisioned by the "NGI and lnternet2 leadership. From a networking perspective, tele-immersion 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 critical to achieving the feel of telepresence, whether synchronous or recorded and played back
¢ The computers, too, are bandwidth limited with regard to handling very large data for collaboration
¢ Simulation and data mining are open-ended in computational and bandwidth needs”there will never be quite enough computing and bits/second to fully analyze, and simulate reality for scientific purposes.
In Layman's language the realization of tele-immersion 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
SOLUTION
The first two basic problems can be overcome when lnternet-2 will come into picture later and third problem can be overcome by the fast development of image compression techniques. ABOUT INTERNET-2
¢ lnternet2 is not a separate physical network and will not replace the current Internet. It is not for profit consortium consisting of 200 US universities. Industries and is directly under the control of US govt..
¢ Internet2 is for developing and deploying advanced network applications and technology, accelerating the creation of tomorrow's Internet.
¢ Internet2 enables completely new applications such as digital libraries, virtual laboratories, distance-independent learning and tele-immersion.
i
" ¢ A key goal of this effort is to accelerate the diffusion of advanced Internet
¢ technology, in particular into the commercial sector.
jj
i 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. Internet^ research targeted in the development of new protocols for handling applications that demand very high bandwidth and very low, controlled latencies (delay is reduced by processing signals along their travel through the network).
We need a powerful network with high speed and high bandwidth to transfer the large amounts of data that tele-immersion will produce.Internet2 will replace the current Internet infrastructure. This new network will have a higher bandwidth and speeds that are 1000 times faster than today's Internet. This high-bandwidth, high-speed provided by lnternet2 is sufficient to transfer the large amounts of data that tele-immersion will produce.
Dept.ofCSE
16
SNGCE.IColencliery
Internet 2 had a peculiar problem : no existing applications that requires the high level of performance provided by internet 2 except teleimmersion
Desktop supercomputers
The Grid will use distributed computing. There are not enough supercomputers to deal with the enormous amounts of data that will 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. They will be locked in to a grid-effectively creating one supercomputer. About a dozen American universities are doing research on various aspects of immersive technologies, including USC, the University of North Carolina, the University of Pennsylvania and Brown University Mainly two institutions called PENN and UNC (University of north Carolina) are doing researches in tele immersion.
Bandwidth issues
j Network bandwidth required to make tele-immersion work
! is one of the main concerns of this new technology. It is estimated that as much as 1.2 j gigabits per second will be needed for future high-quality effects. This is much higher j than the average home connection bandwidth. The 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 reduce as advanced compression techniques are established. Initially, bandwidth-intensive applications will have to be limited to the larger organizations that can afford high connection speeds
TELE-IMMERSION
1 CURRENT DEVELOPMENTS
Haptic sensors: Miniaturized force/torque sensors
j 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, capacitive, piezoelectric, or optical elements to detect force. A critical problem with these 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.
j
Recently, much research has focused on reducing this problem by inventing thinner and more flexible force-sensing pads, a new approach to the detection of finger forces is presented in order to completely eliminate any impediment to the natural haptic sense and hence the name 'haptic sensors'. (Haptic means that ' relating to or based on the sense of touch ' ). An optical sensor mounted on the fingernail " detects the force. This allows the human to touch the environment with bare fingers and 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 fingernail covering.
.Haptic sensor is a new type of touch sensor for detecting contact pressure at human fingertips. Hence the sensor is mounted on the fingernail rather San 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 when the fingertip is pressed against a surface. The changes in intensity are then used to determine changes in the blood volume under the fingernail, a technique termed "reflectance photoplethysmography." A homodynamtc model is used to investigate the dynamics of the blood volume at two locations under the fingernail. A miniaturized prototype nail sensor is de-signed, built, and tested. The theoretical analysis is verified through experiment and simulation.
Fig :Implementation of fingernail touch sensors Figure shows the implementation of fingernail touch sensors. For the prototype shown here, two photodiode arrays of dimension 4 mm 1 mm are attached end to end on the bottom side. Up to 8 of the 32 total photodiodes can be wired up at once, resulting in up to eight sensing locations along the length of the fingernail. Up to three LEDs of dimension 0.25 mm 0.25 mm can be placed in flexible locations beside the photodiode arrays.
Haptic sensors would allow people to touch projections as if they were real. A 3D sensor and supporting software has been developed and patented that enables the real-time visualization of the haptic sense of pressure. Haptic sensors can be used in tele immersion systems to sense the pressure and reconstruct the feeling of touch in combination with other devices
CONCLUSION
Tele-Immersion is a fast developing technology and it is going to benefit the common man once Internet-2 comes into picture. It is of immense use in the field of S Medicine
S It helps in reducing business travel S 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-Immersion is a technology that is certainly going to bring a new revolution in the world and let us all hope that this technology reaches the world in its full flow as quickly as possible.
FUTURE SCOPE
The tele-immersion system of 2010 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 Al-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 NTH (National Tele-Immersion Initiative).
BIBLIOGRAPHY
1. www .tele-immersion.citris-uc.org2, fp.mcs.anl.gov3. ieee.com4. NTll.com5. advancedorg.tele-immersion.com6. newscientist.com7. internet2.edu8. cis.upenn.edu9. mrl.nyu.edu10. howstuffworks.com


CONTENTS
¢ Introduction ....1
¢ The History.... 1
¢ What is tele- immersion ... .2
¢ Requirements of Tele immersion ....3
¢ 3D environment scanning ... .3 Reconstruction in a holographic environment.. ..6 Projective and display technologies ... .7 Tracking technologies ... .7
Moving sculptures ....7
¢ Audio technologies ... .8 Powerful networking ....8 Computational needs ....9
¢ Tele cubicle ....10
¢ Tele immersion studio.... 11
¢ Applications....12
¢ Challenges of Tele-Immersion.... 15
¢ Solution....16
¢ About Internet^.... 16
¢ Desktop Supercomputers.... 17
¢ Bandwidth issues.... 17
¢ Current developments.... 18
¢ Conclusion....20
¢ Future scope ....21
¢ Bibliography ....22

[attachment=2751]

TELE-IMMERSION
PRESENTED BY:
SWAGATIKA MISRA
WHAT IS TELE-IMMERSION?
A developing application of Internet2 intended to allow multiple, geographically distributed users to collaborate in real time in a shared, simulated hybrid environment through a synthesis of media technologies such as three-dimensional (3D) environment scanning, projection and display, tracking, audio, video, robotics technologies.
WHY TELE-IMMERSION?
Drawbacks of Tele-conferencing are
¢ Poor sound and Image Quality
¢ Unacceptable delays
¢ Eye-contact problem
WHY TELE-IMMERSION?
The eye-to-eye problem is solved by tele-immersion a technology that goes several steps beyond teleconferencing to create the illusion that people separated by distance are together in the same room.
Using high-bandwidth networks and clusters of video cameras linked to banks of computers, tele-immersion scans a person's face and body and creates a kind of living statue that other tele-immersion participants see displayed on a large screen.
The overall effect is like talking face to face to another person, separated by a pane of glass.
OFFICE OF THE FUTURE !!!
Our goals include a better everyday graphical display environment, and 3D tele-immersion capabilities that allow distant people to feel as though they are together in a shared office space.
GROUP TELE-IMMERSION
Group Tele-Immersion (GTI) is for enabling high fidelity and immersive teleconferencing between groups at distant locations.
GROUP TELE-IMMERSION
3 projector display with 8 capture cameras mounted above the display
LINE SIGHT FIELD DESIGN:
Abutted projector display with a dense horizontal camera array at table level and actual camera array implementation
GROUP TELE-IMMERSION
Remote participants and local participants with display
INTERNET CONFERENCING
Conference at the internet also can be possible with more sophisticated compression scheme and increased frame rate with Tele-immersion.
BENEFITS :
¢ High reliability
¢ Propagation Delay and queuing is
less.
¢ Low latency data-transfer
¢ Advanced data transfer techniques
¢ Better quality of service.
¢ High throughput techniques
LIMITATIONS:
Tele-immersion has been one of the major developments but still there is one thing still left is the physical contact of individual at each end.
APPLICATIONS
Design and virtual prototyping, maintenance and repair, paleontological and archeological & Reconstruction.
In fields such as architecture, medicine, astrophysics and aeroplane design
SUMMARY
Overally Tele-Immersion can be
summarized as
Collaboration at geographically distributed sites in real-time
Synthesis of networking and media technologies
Full integration of Virtual Reality into the workflow
THANK
YOU!!!

[attachment=6145]

Technologies for Virtual Reality/Tele-Immersion Applications:
Issues of Research in Image Display and Global Networking

Tom DeFanti, Dan Sandin, Maxine Brown,
Dave Pape, Josephine Anstey, Mike Bogucki, Greg Dawe, Andy Johnson
Electronic Visualization Laboratory (EVL)
University of Illinois at Chicago
851 S. Morgan St., Room 1120
Chicago, IL 60607-7053 USA

Thomas S. Huang
Beckman Institute for Advanced Science and Technology
University of Illinois at Urbana-Champaign
405 N. Mathew Ave.
Urbana, IL 61801 USA

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Abstract
The Electronic Visualization Laboratory (EVL) at the University of Illinois at Chicago (UIC) has developed an
aggressive program over the past decade to partner with scores of computational scientists and engineers all over the
world. The focus of this effort has been to create visualization and virtual reality (VR) devices and applications for
collaborative exploration of scientific and engineering data. Since 1995, our research and development activities
have incorporated emerging high bandwidth networks like the vBNS and its international connection point STAR
TAP, in an effort now called tele-immersion.
As a result of eight years’ experience building first and second-generation projection-based VR devices to support
these applications, we wish to describe needed research in third-generation VR devices aimed at desktop/officesized
displays. Since no current projection technology is yet configurable with ideal resolution and size, we must first
describe the variety of emerging display devices, such as large color plasma displays, LCD projectors, LED panels,
Digital Light Valves (DLVs), Grating Light Valves (GLVs), and Digital Micro Mirror Displays (DMDs ).

[attachment=7431]

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TELE IMMERSION

TELE IMMERSION

OVERVIEW
INTRODUCTION
REQUIREMENTS FOR IMMERSIVE TELECONFERENCE SYSTEM
HOW TELE-IMMERSION WORKS
SHARED TABLE ENVIRONMENT
NOVEL VIEW SYNTESIS
TELE-CUBICLES
COLLABORATION WITH I2 & IPPM
PRESENT RESEARCH
CONCLUSION

INTRODUCTION
NTII TEAM ARE WORKING ON PROJECTS TO HAVE USERS THE SAME PHYSICAL SPACE IN A REAL TIME WORLD,AS IF THEY ARE SITTING IN FRONT OF EACH OTHER IN THE SAME ROOM.
IN THIS REGARD ADVANCED NETWORK & SERVICES PLAYED A VITAL ROLE ,TO BRING THE EXPERTS IN THIS FIELD CLOSE TOGETHER.
THIS TEAM IS LED BY JARON LANIER,WHO WAS THE ONE OF THE PIONEERS IN DEVELOPMENT OF VIRTUAL REALITY.
NTII TEAM STARTED THEIR WORK IN THE MIDDLE OF 1997 AND THE COLLABRATING SCHOOLS WERE BROWN UNIVERSITY,PROVIDENCE NAVAL POSTGUARD SCHOOL,MONTEREY UNIVERSITY OF NORTH CAROLINA,CHAPEL HILL AND UNIVERSITY OF PENNSYLVANIA,PHILADELPHIA.

DEFINITIONS:-
Jason Leigh “The term tele-immersion was first used…….as the title of a workshop….to bring together researchers in distributed computing,collaboration,virtual reality and networking.”

Watsen & Zyla “It enable the interaction between geographically remote participants within a shared,3-D space.”
FIRST FEEL OF TELE-IMMERSION
MAIN AIM OF THE TEAM WAS TO TAKE INTO ACCOUNT THE ULTIMATE SYNETHESIS OF MEDIA TECHNOLOGIES FOR SCANNING AND TRACKING OF 3D ENVIRONMENT.
IT WAS BASED ON VISION BASED 3D RECONSTRUCTION.
THE FIRST EXPERIMENT WAS CONDUCTED IN CHAPEL HILL LED BY THE SCIENTISTS HENRY FUCHS AND GREG WELCH.
IT LINKED CHAPEL HILL,THE UNIVERSITY OF PENNSYLVANIA AND ADVANCED NETWORK &SERVICES AT NEWYORK.
RESEARCHERS CAN PEER INTO THE OFFICE OF THEIR COLLEAGUES HUNDEREDS OF MILES AWAY.
THE APPARATUS OF THE TEST CONSISTED OF TWO LARGE SCREENS,PROJECTION CAMERAS AND HEAD TRACHING GEAR.
ONE SCREEN WAS AT LEFT SIDE OF WELCH AND OTHER WAS ON RIGHT.

THROUGH LEFT WALL WELCH CAN SEE HIS COLLEGEUS AT PHILADELPHIA (UNIVERSITY OF PENNSYLVANIA ) AND THROUGH THE RIGHT AT NEWYORK.HE FELT THAT THEY WERE SITTING ACROSS THE DESK FROM HIM.
WHEN WELCH CHANGED POINT OF VIEW, THE IMAGES SHIFTED IN A NATURAL WAY.
IF HE LEANED IN, IMAGES GOT LARGER, IF HE LEANED OUT, THEY GOT SMALLER. HE COULD EVEN TURN HIS NECK TO LOOK AROUND THE PEOPLE.


REQUIREMENTS FOR IMMERSIVE TELE CONFERENCE SYSTEMS
NECESSARY TO USE A LARGE DISPLAY THAT COVERS ALMOST THE WHOLE VIEWING ANGLE OF THE VISUAL SYSTEM.
ALSO THE LARGE DISPLAY HAS TO BE INTEGRATED INTO THE USUAL WORKSPACE OF AN OFFICE OR A MEETING ROOM.
A DESKTOP-LIKE ARRANGEMENT WITH LARGE FLAT SCREEN LIKE PLASMA DISPLAYS
PERSONS ARE SEAMLESSLY INTEGRATED IN THE SCENE AND DISPLAYED WITH AT LEAST HEAD,SHOULDERS,TORSO AND ARMS IN NATURAL LIFE-SIZE.
ALL VISUAL PARAMETERS OF THE SCENE AND THE DIFFERENT SOURCES HAVE TO BE HARMONISED.
THE PERSPECTIVE OF THE SCENE IS PERMANATLY ADAPTED TO THE CURRENT VIEWPOINT OF THE PERSON IN FRONT OF THE DISPLAY
EYE-CONTACT BETWEEN TWO PARTNERS TALKING TO EACH OTHER HAS TO BE PROVIDED

GAZE FROM ONE PERSON TO ANOTHER HAS TO BE REPRODUCED IN A SUFFICIENT MANNER SUCH THAT EVERYBODY CAN RECOGNISE WHO IS TALKING AT WHOM.
VOICE OF A PERSON MUST CAME FROM THE SAME DIRECTION WHERE HE IS POSITONED ON THE SCREEN.
HOW TELE-IMMERSION WORKS


SHARED TABLE ENVIRONMET
A VERY ATTRACTIVE WAY TO MEET THE ABOVE REQUIREMENTS IS TO FOLLOW THE PRINCIPLE OF A SHARED TABLE ENVIRONMENT.
IT IS BASED ON THE IDEA TO POSITION THE PARTICIPANTS CONSISTENTLY IN A VIRTUAL ENVIRONMENT AROUND A SHARED TABLE.

AT THE TRANSMITTING SIDE THE CONFEREE IN FRONT OF THE DISPLAY IS CAPTURED BY MULTIPLE CAMERAS AND A 3D IMAGE OF THE CONFEREE IS DERIVED FROM THIS MULTIVIEW SET-UP.
THE 3D IMAGES OF ALL PARTICIPATING CONFEREES ARE THEN PLACED VIRTUALLY AROUND A SHARED TABLE.
IDEALLY, THIS IS DONE IN A ISOTROPIC MANNER IN ORDER TO OBTAIN SOCIAL SYMMETRY.
HENCE, IN THE CASE OF THREE-PARTY CONFERENCE THE PARTICIPANTS FORM A EQUILATERAL TRIANGLE. IN THE CASE OF FOUR PARTIES IT WOULD BE A SQUARE, AN EQUILATERAL PENTAGON FOR A FIVE-PARTY SYSTEM, AND SO ON.

AT THE RECEIVING END THE ENTIRELY COMPOSED 3D SCENE IS RENDERED ONTO THE 2D DISPLAY OF THE TERMINAL BY USING A VIRTUAL CAMERA.
THE POSITION OF THE VIRTUAL CAMERA COINCIDES WITH THE CURRENT POSITION OF THE USER'S HEAD.
FOR THIS PURPOSE THE HEAD POSITION IS PERMANENTLY REGISTERED BY HEAD TRACKER AND THE VIRTUAL CAMERA IS MOVED WITH THE HEAD.
GENERATING 3D IMAGES
GENERATING 3D IMAGES(cont)
TELE-CUBICLES
A TELE-CUBICLE IS AN OFFICE THAT CAN APPEAR TO BECOME ONE QUADRANT IN A LARGER SHARED VIRTUAL OFFICE SPACE .

THE APPARATUS CONSISTS OF:
 DESK SURFACE (STEREO IMMERSIVE DESK)
 TWO WALL SURFACES
 TWO OBLIQUE FRONT STEREO PROJECTION SOURCES (MIGHT BE INTEGRATED WITH PROJECTORS)

 THE THREE DISPLAY SURFACES MEET, IN THE FORMATION OF A DESK AGAINST A CORNER.
WHEN A TELECUBICLE IS LINKED TO OTHERS ON THE NET, THE WALLS APPEAR TO BE TRANSPARENT PASSAGES TO THE OTHER CUBICLES.
FOUR TELECUBICLES CAN BE JOINED IN VIRTUAL SPACE SO THAT EACH FORMS A QUADRANT OF A LARGER VIRTUAL WHOLE.
THE DESK SURFACES LINE UP TO FORM A LARGE TABLE IN THE MIDDLE OF THE VIRTUAL SHARED ROOM.
THROUGH THE WALLS CAN BE SEEN THE OTHER PARTICIPANTS AS WELL AS PROPS, FURNITURE, AND OTHER PHYSICAL FEATURES OF THEIR ENVIRONMENTS.
VIRTUAL OBJECTS AND DATA CAN BE PASSED THROUGH THE WALLS BETWEEN PARTICIPANTS, AND PLACED ON THE SHARED TABLE IN THE MIDDLE FOR VIEWING.
APPLICATIONS OF TELE-IMMERSION
THE LIST OF APPLICATIONS OF TELE-IMMERSION IS VERY LARGE. SOME OF THEM ARE:

ABSTRACT


Tele-immersion is aimed to enable users in geographically distributed sites to collaborate in real time in a shared simulated environment as if they were in the same physical room. Tele-immersion is aimed to be used in different areas, such as3D CAD design, entertain ment(e.g. games), remote learning and training, 3D motion capturing.We define tele-immersion as that sense of shared presence with distant individuals and their environments that feels substantially as if they were in one's own local space. One of the first visitors to our tele-immersion system remarked "It's as if someone took a chain saw and cut a hole in the wall [and I see the next room]." This kind of tele-immersion differs significantly from conventional video teleconferencing in that the user's view of the remote environment changes dynami cally as he moves his head. .
Tele-immersion is a technology to be implemented with Internet2 that will enable users in different geographic locations to come 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.
Such approaches are geared toward exploration of abstract data; our vision, instead, is of a realistic distributed extension to our own physical space, this presents challenges in environment sampling,transmission, reconstruction , presentation, and user interaction.Other approaches that concentrate on realistic rendering of participants in a shared tele-conference do not employ the extensive local environment acquisition necessary to sustain a seamless blending of the real and synthetic locales.
Tele-immersion presents the greatest technological challenge for Internet2etc.

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By:
KANNAN K M

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INTRODUCTION

Tele Immersion is a new medium that enables a user to share a virtual space with remote participants. The user is immersed in a 3D world that is transmitted from a remote site. This medium for human interaction, enabled by digital technology, approximates the illusion that a person is in the same physical space as others, even though they may be thousands of miles distant.In a tele-immersive environment computers recognize the presence and movements of individuals and objects, track those individuals and images, and then permit them to be projected in realistic, multiple, geographically distributed immersive environments on stereo-immersive surfaces.Tele-immersion techniques can be viewed as the building blocks of the office of tomorrow, where several users from across the country will be able to collaborate as if they're all in the same room. Scaling up, transmissions could incorporate larger scenes, like news conferences, ballet performances, or sports events. With mobile rather than stationary camera arrays, viewers could establish tele-presence in remote or hazardous situations. Properly, for instance, in today’s video-conferencing systems, because the camera and the display screen cannot be in the same spot. This usually leads to a deadened and formal affect in interactions, eye contact being a nearly ubiquitous subconscious method of affirming trust. Furthermore, participants aren’t able to establish a sense of position relative to one another and therefore haven clear way to direct attention, approval or disapproval.Teleimmersion, a new medium for human interaction enabled by digital technologies, approximates the illusion that a user is in the same physical space as other people, even though the other participants might in fact be 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, teleimmersion stations convey them as “moving sculptures,” point of view. The result is that all the participants, however distant, can share and explore a life-size space. Beyond improving on videoconferencing, teleimmersion was conceived as an ideal application for driving network-engineering research, specifically for Internet2, the primary research consortium for advanced network studies in the U.S. If a computer network can support teleimmersion, it can probably support any other application. This is because teleimmersion 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 .


SCIENCE OF TELE-IMMERSION

Tele-Immersion has an environment called TIDE. TIDE stands for Tele-Immersive Data exploration Environment. The goal of TIDE is to employ Tele-Immersion techniques to create a persistent environment in which collaborators around the world can engage in long-term exploration and analysis of massive scientific data-sets. When participants are tele-immersed, they are able to see and interact with each other and objects in a shared virtual environment. Their presence will be depicted by life-like representations of themselves (avatars) that are generated by real-time, image capture, and modeling techniques. The environment will persist even when all the participants have left it. The environment may autonomously control supercomputing computations, query databases and gather the results for visualization when the participants return. Participants may even leave messages for their colleagues who can then replay them as a full audio, video and gestural stream.
All users are separated by hundreds of miles but appear collocated able to see each other as either a video image or as a simplified virtual representation (commonly known as an avatar). Each avatar has arms and hands so that they may convey natural gesture such as pointing at areas of interest in the visualization. Digital audio is streamed between the sites to allow them to speak to each other. TIDE will engage users in CAVEs, ImmersaDesks and desktop workstations around the world connected by the Science and Technology Transit Access Point (STARTAP) - a system of high speed national and international networks. TIDE

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INTRODUCTION
Tele-immersion may be the next major development in information technology. Using tele-immersion, you can visit an individual across the world without stepping a foot outside.
1.1 What is tele-immersion?
Tele-Immersion is a new medium that enables a user to share a virtual space with remote participants. The user is immersed in a 3D world that is transmitted from a remote site. This medium for human interaction, enabled by digital technology, approximates the illusion that a person is in the same physical space as others, even though they may be thousands of miles distant. It combines the display and interaction techniques of virtual reality with new computer-vision technologies. Thus with the aid of this new technology, users at geographically distributed sites can collaborate in real time in a shared, simulated, hybrid environment submerging in one another’s presence and feel as if they are sharing the same physical space.
It is the ultimate synthesis of media technologies:
• 3D environment scanning,
• projective and display technologies,
• tracking technologies,
• audio technologies,
• robotics and haptics,
and powerful networking. The considerable requirements for tele-immersion system, make it one of the most challenging net applications.
In a tele-immersive environment computers recognize the presence and movements of individuals and objects, track those individuals and images, and then permit them to be projected in realistic, multiple, geographically distributed immersive environments on stereo-immersive surfaces. This requires sampling and resynthesis of the physical environment as well as the users' faces and bodies, which is a new challenge that will move the range of emerging technologies, such as scene depth extraction and warp rendering, to the next level.
Tele-immersive environments will therefore facilitate not only interaction between users themselves but also between users and computer generated models and simulations. This will require expanding the boundaries of computer vision, tracking, display, and rendering technologies. As a result, all of this will enable users to achieve a compelling experience and it will lay the groundwork for a higher degree of their inclusion into the entire system
Tele-immersive systems have potential to significantly change educational, scientific and manufacturing paradigms. They will show their full strength in the systems where having 3D reconstructed ‘real’ objects coupled with 3D virtual objects is crucial for the successful fulfillment of the tasks. It may also be the case that some tasks would not be possible to complete without having such combination of sensory information. There are several applications that will profit from tele-immersive systems. Collaborative mechanical CAD applications as well as different medical applications are two that will benefit significantly.
Tele-immersion may sound like conventional video conferencing. But it is much more. Where video conferencing delivers flat images to a screen, tele-immersion recreates an entire remote environment. Although not so, tele-immersion may seem like another kind of virtual reality. Virtual reality allows people to move around in a pre-programmed representation of a 3D environment, whereas tele-immersion is measuring the real world and conveying the results to the sensory system.
2. System Overview And Algorithms
A tele-immersion telecubicle is designed both to acquire a 3D model of the local user and environment for rendering and interaction at remote sites, and to provide an immersive experience for the local user via head tracking and stereoscopic display projected on large scale view screens.

Submitted By
G.Vinuthana

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1. Abstract:
The past people only dream about communicating geographically but the advancement in telecommunication along with advancement in media techniques make it possible. But still there was struggle to make them collaborate in a real time world, like efforts to have users share the same physical space, during there meetings, conferences, etc. National Tele-Immersion Initiative – NTII team leads the way to make all these things possible. They are working on projects to have users share the same physical space in a real time world, as if they are sitting in front of each other in the same room. In this regard Advanced Network & Services played a vital role, to bring together the experts in this field close together. This team is lead by Jargon Lanier, Who was one of the pioneers in development of Virtual Reality (which according to him is “the brain anticipates a virtual world instead of the physical one”) in 1980’s. National Tele-Immersion team started there work in middle of 1997 and the collaborating schools were Brown University, Providence Naval Post guard School , Monterey University of North Carolina, Chapel Hill and University of Pennsylvania, Philadelphia.
In start the main aim of the team was to take into account the ultimate synthesis of media technologies for the scanning and tracking of three dimensional environments. Based on vision based three dimensional reconstruction with the help of new advancement in fields like media technologies, networking, robotics. In May 2000 whole the hectic efforts of the team cope up with some success, with first demonstration of three years long work. National TeleImmersion Initiative team lead by virtual reality pioneer Jargon Lanier, conducted which at one stage was just imagination. This effort lead to the thinking which could change the way we communicate over long distances, people could feel each other submerge together in the same physical space. The experiment was conducted in Chapel Hill led by UNC computer scientists Henry Fuchs and Greg Welch. It linked UNC Chapel Hill, the University of Pennsylvania in
Philadelphia and Advanced Network & Services at New York. Researchers at each place could feel themselves in the office of their colleagues hundreds of miles far apart. The apparatus of the test consisted of two large walls, projection cameras and head tracking gear. One screen was at left side of Welch and other was on right. Through left wall Welch can see his colleagues at Philadelphia and through other of New York. He can peep in and out and images change accordingly, like when he leaned forward images grew larger and become smaller when he moved back. At each target site there were digital cameras to capture the image and laser rangefinders to gather information regarding the position of the object. Computer then converted them into a three dimensional information which was then transmitted to Chapel Hill via Internet2, where computers were mounted to reconstruct the image and display that on the screen.
To some point it seems that Tele-Immersion is another kind of Virtual Reality but Jargons Lanier is of other view. According to him “virtual reality allows people to move around in a preprogrammed representation of a 3D environment, whereas tele-immersion is more like photography. It's measuring the real world and conveying the results to the sensory system
2. REQUIREMENTS FOR IMMERSIVE TELECONFERENCE SYSTEMS:
To meet the requirements of immersion, it is absolutely necessary to use a large Display that covers almost the whole viewing angle of the visual system. In addition, the large display has to be integrated into the usual workspace of an office or a meeting room. Thus, the most practicable solution is a desktop-like arrangement with large flat screens like plasma displays with a diagonal of 50 inch and more. Starting from such a desktop-like system and taking into account results from intensive human factors research, further requirements on the presentation of the scene can be formulated as follows:
• Conferees are seamlessly integrated in the scene and displayed with at least head, shoulders, torso and arms in natural life-size
• All visual parameters of the scene and the different sources have to be harmonized
• The perspective of the scene is permanently adapted to the current viewpoint of the conferee in front of the display (head motion parallax; look-behind effect)
• Eye-contact between two partners talking to each other has to be provided
• Gaze from one conferee to another has to be reproduced in a sufficient manner such that everybody can recognize who is looking at whom (e.g.: who is searching for eye contact)
• Voice of a conferee must come from the same direction where he is positioned on
the screen.
3. SHARED TABLE ENVIRONMENT:
A very attractive way to meet the above requirements is to follow the principle of a share table environment. It is based on the idea to position the participants consistently in a virtual environment around a shared table. At the transmitting side the conferee in front of the display is captured by multiple cameras and a 3D image of the conferee is derived from this multitier set-up. The 3D images of all participating conferees are then placed virtually around a shared table. Ideally, this is done in a isotropic manner in order to obtain social symmetry. Hence, in the case of three-party conference the participants form a equilateral triangle. In the case of four parties it would be a square, an equilateral pentagon for a five-party system, and so on. At the receiving end this entirely composed 3D scene is rendered onto the 2D display of the terminal by using a virtual camera. 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 head tracker and the virtual camera is moved with the head. Thus, supposing that the geometrical parameters of the multi-view capture device, the virtual scene and the virtual camera are well fitted to each other, it is ensured that all conferees see the scene under the right perspective view, even while changing their own viewing position. As the consequence, they can also change the view knowingly in order to watch the scene from another perspective, to look behind objects or to look at a previously occluded object. Moreover, all deviations of the conferees' position from a default position are picked up by the multi-view capture devices. Thus, again supposing well fitted geometrical relations, the 3D image will be moved equivalently in the virtual world and, as a consequence, the other conferees can follow the resulting perspective changes at their displays. These circumstances ensure a natural reproduction of eye-contacts and body language in the case of direct face-to-face communication between two partners as well as a natural perspective of this bilateral communication from the position of the third conferee. Last, but not least - the isotropic scene composition and the resulting symmetry enable that the displays can be also placed symmetrically between the partners (i.e. at the middle of the direct viewing axis). Thus, the display works similar to a mirror. Hence, all portrayals appear well balanced in natural life-size at the displays and a psychologically dominance of particular participants is avoided.

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