SEMINAR ON 3D TELEVISION Submitted by: SUSHEELKUMAR S W U.S.N : 1RC08EC414
Abstract : Three-dimensional TV is expected to be the next revolution in the TV history. They implemented a 3D TV prototype system with real-time acquisition transmission, & 3D display of dynamic scenes. They developed a distributed scalable architecture to manage the high computation & bandwidth demands. 3D display shows high-resolution stereoscopic color images for multiple viewpoints without special glasses. This is first real time end-to-end 3D TV system with enough views & resolution to provide a truly immersive 3D experience.Japan plans to make this futuristic television a commercial reality by 2020as part of abroad national project that will bring together researchers from the government, technology companies and academia. The targeted "virtual reality" television would allow people to view high definitionimages in 3D from any angle, in addition to being able to touch and smell the objects being projected upwards from a screen to the floor.
Keywords--- parallex,display,perception,holographic images INTRODUCTION
Three-dimensional TV is expected to be the next revolution in the TV history. They implemented a 3D TV prototype system with real-time acquisition transmission, & 3D display of dynamic scenes. They developed a distributed scalable architecture to manage the high computation & bandwidth demands. 3D display shows high-resolution stereoscopic color images for multiple viewpoints without special glasses. This is first real time end-to-end 3D TV system with enough views & resolution to provide a truly immersive 3D experience.
Why 3D TV
The evolution of visual media such as cinema and television is one of the major hallmarks of our modern civilization. In many ways, these visual media now define our modern life style. Many of us are curious: what is our life style going to be in a few years? What kind of films and television are we going to see? Although cinema and television both evolved over decades, there were stages, which, in fact, were once seen as revolutions: 1) at first, films were silent, then sound was added; 2) cinema and television were initially black-and-white, then color was introduced; 3) computer imaging and digital special effects have been the latest major novelty. ARCHITECTURE OF 3D TV
Figure 5 shows the schematic representation of 3D TV system.
The whole system consists mainly three blocks:
1 Aquisition
2. Transmission 3. Display Unit
A. Acquisition The acquisition stage consists of an array of hardware-synchronized cameras. Small clusters of cameras are connected to the producer PCs. The producers capture live, uncompressed video streams & encode them using standard MPEG coding. The compressed video then broadcast on separate channels over a transmission network, which could be digital cable, satellite TV or the Internet. Generally they are using 16 Basler A101fc color cameras with 1300X1030, 8 bits per pixel CCD sensors.
1) CCD Image Sensors: Charge coupled devices are electronic devices that are capable of transforming a light pattern (image) into an electric charge pattern (an electronic image). Figure 6 shows CCD sensors. Fig.5.4 Arrays of 16 Cameras
B. Transmission Transmitting 16 uncompressed video streams with 1300X1030 resolution & 24 bits per pixel at 30 frames per seconds requires 14.4 Gblsec bandwidth, which is well beyond current broadcast capabilities. For compression & transmission o1 dynamic muitiview video data there are two basic design choices. Either the data from multiple cameras is compressed using spatial or spatio-temporal encoding, or each video stream is compressed individually using temporal encoding. The first option offers higher compression, since there is a lot of coherence between the views. However, it requires that a centralized processor compress multiple video streams. Fig.5.5 Modified System
1) Gigabit Ethernet: It a transmission technology, enables Super Net to deliver enhanced network performance. Gigabit Ethernet is a high speed form of Ethernet (the most widely installed LAN technology), that can provide data transfer rates of about 1 gigabit per second (Gbps). Gigabit Ethernet provides the capacity for server interconnection, campus backbone architecture and the next generation of super user workstations with a seamless upgrade path from existing Ethernet implementations.
2)Decoder & Consumer Processing: The receiver side is responsible for generating the appropriate images to be displayed. The system needs to be able to provide all possible views to the end users at every instance. The decoder receives a compressed video stream, decode it, and store the current uncompressed source frame in a buffer as shown in figure 10. Each consumer has virtual video buffer (VVD) with data from all current source frames. (I.e., all acquired views at a particular time instance). Fig.5.6 Block Diagram of Decoder and Consumer processing
The consumer then generates a complete output image by processing image pixels from multiple frames in the VVB. Due to the bandwidth 8 processing limitations it would be impossible for each consumer to receive the complete source of frames from all the decoders. This would also limit the scalability of the system. Here is one-to-one mapping between cameras & projectors.
3D DISPLAY
This is a brief explanation that we hope sorts out some of the confusion about the many 3D display options that are available today. We'll tell you how they work, and what the relative tradeoffs of each technique are. Those of you that are just interested in comparing different Liquid Crystal Shutter glasses techniques can skip to the section at the end. Of course, we are always happy to answer your questions personally, and point you to other leading experts in the field[4]. Figure shows a diagram of the multi-projector 3D displays with lenticular sheets. Fig.7.1 Projection-type lenticular 3D displays
They use 16 NEC LT-170 projectors with 1024'768 native output resolution. This is less that the resolution of acquired & transmitted video, which has 1300'1030 pixels. However, HDTV projectors are much more expensive than commodity projectors. Commodity projector is a compact form factor. Out of eight consumer PCs one is dedicated as the controller. The consumers are identical to the producers except for a dual-output graphics card that is connected to two projectors. CONCLUSION
Most of the key ideas for 3D TV systems presented in this paper have been known for decade, such as lenticular screens, multi projector 3D displays, and camera array for acquisition. This system is the first to provide enough view points and enough pixels per view points to produce an immersive and convincing 3D experience. Another area of future research is to improve the optical characteristic of the 3D display computationally. This concept is computational display. Another area of future research is precise color reproduction of natural scenes on multiview display.
REFERENCES
[1] An Assessment of 3DTV Technologies, Levent Onural-Bilkent Un.,Thomas Sikor- Tech. Univ. Of Berlin, Jorn Ostermann- Univ. Of Hanover, Aljoscha Smolic- Fraunhofer Inst.-HHI, M. Reha Civanlar- Koc Univ., John Watson- Univ. Of Aberdeen, NAB-2006 - Las Vegas - 26 April 2006 c Copyright 2006. [2] T. Capin, K. Pulli, and T. Akenine-Moller, “The State of the Art in Mobile Graphics Research”, IEEE Computer Graphics and Applications, vol. 28, no. 4, pp. 74 - 84,2008. [3] K. Muller, P. Merkle, and T. Wiegand, “Compressing 3D Visual Content”, IEEE Signal Processing Magazine, vol. 24, no. 6, pp. 58-65, November 2007. [4] T. Okoshi, "Three dimensional displays," Proceedings of the IEEE, vol. 68, pp. 548- 564, 1980. [5] I. Sexton, and P. Surman, “Stereoscopic and auto stereoscopic display systems,” IEEE Signal Processing Magazine, vol. 16, no. 3, pp. 85-99, 1999. [6] P C. Fehn, P. Kauff, M. Op De Beeck, F. Ernst, W. IJsselsteijn, M. Pollefeys, L. Van Gool, E. Ofek and I. Sexton, “An Evolutionary and Optimized Approach on 3D-TV”, Proc. of International Broadcast Conference, 2002. [7] C. Fehn, “A 3D-TV approach using depth image- based rendering (DIBR)”, Proc. Of VIIP 2003.