Reduced Dual-Mode Mobile 3D Display Using Crosstalk

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1 Reduced Dual-Mode Mobile 3D Display Using Crosstalk Priti Khaire, Student (BE), Computer Science and Engineering Department, Shri Sant Gadge Baba College of Engineering and Technology, Bhusawal, North Maharashtra University, Jalgaon, Maharashtra, India Abstract: I studied a new changed novel on crosstalkreduced mobile 3D display system which providing high quality 3D images in representation mode and also landscape mode. In this paper, a mathematical definition is studied and a new changed which uses a physical approach.. To reduce crosstalk, when the display s black level is not zero, it must be subtracted out and when the source intensities are equal, crosstalk can be measured using observed intensities totally within the respective view. I adopt the mobile phone with a diamond pentile display panel. They build and I studied it and show with a new changed parallax barrier film and diamond pentile display. is required which is bulky and heavy. Recently, a film-type micro lens array sheet and real-time image rendering program called EyeFly 3D was commercialized which can offer high quality 3D images in dual-mode. However, it is problematic in the sense of high crosstalk and a difference in image quality in dual-mode. In this seminar, we propose a crosstalk-reduced mobile 3D display system that provides high quality 3D images in dual-mode. A preliminary approach was introduced by our group recently. Fig. 1 shows a schematic diagram of the proposed 3D display system in dual-mode.. Keywords: Mobile Display, Multi-View Display, Three-Dimensional (3D) Display. I. INTRODUCTION Recently, the 3D display system has been remarkably developed along with the growth of flat panel display technology and various optical devices [1]. However, it cannot yet provide high resolution 3D image with high depth range to multiple viewers without the use of special glasses. Since an auto stereoscopic 3D display system usually depends on light ray information from a 2-D display, it is difficult to reconstruct a high quality 3D image with it as good as a 2-D image. To solve this data capacity problem, some researchers have proposed multiplexing 2-D displays either temporally [1] or spatially [1]. However, these multiplexed systems are bulky, expensive, and fragile [1]. On the other hand, the mobile 3D display industry has also been grown with the expansion of 3D display and smartphone technology. Since a mobile 3D system is usually designed for a single viewer at a fixed viewing distance, it is somewhat free from the data capacity problem mentioned above. Recent mobile phones satisfy the required data capacity of 2-view 3D display system without any multiplexing methods. Since recent mobile phones work both in portrait mode and landscape mode (dual-mode), mobile 3D display systems should also provide 3D images in dual-mode. Several previous researches have been introduced, but the 3D image quality does not concur in dual-mode, or an active liquid crystal (LC) device Figure 1: Structure of conventional dual-mode mobile 3D display EyeFly 3D based on RGB stripe sub pixels. They designed the micro lens array film and we proposed a mapping algorithm for the system. The mobile phone with a diamond pentile display panel to reduce crosstalk. The proposed system can provide high resolution 3D images with lower crosstalk (9%) in dual-mode. Ray tracing simulations were performed to show the validity, and we also built the demonstration with parallax barrier to verify our proposed method. View image separation experiments and intensity distribution measurement experiments were also performed to verify the proposed system. In Seminar, the conventional dual-mode mobile 3D display is analyzed, and the proposed system is introduced. Then, a demonstration with a Available Online@ 291

2 parallax barrier film and a diamond pentile display is described in seminar, experimental results of the view image separation and crosstalk analysis are shown in images and videos. Finally, Section V ends with the conclusion. both portrait and landscape modes. Fig. 2 shows the principle of this dual-mode 3D display system. These viewing zones are about 65 mm apart at the viewing distance so that the observer can see separated view images, like many other multiview systems[1]. II. CROSSTALK-REDUCED DUAL-MODE MOBILE 3D DISPLAY SYSTEM A. Conventional Dual-Mode Mobile 3d Display Based On RGB Stripe Subpixel Recently, a film-type micro lens array sheet and a real-time image rendering program called EyeFly 3D was commercialized [1]. This 2-view 3D display system can provide 3D images in dual-mode with RGB stripe subpixel structure. Fig. 2 shows the micro structure of the micro lens array. The lens pitch is 123 m and slanted at a angle. Since this slanted angle is identical to the arctangent of 3, the vertical lens pitch is 3 times bigger than the horizontal lens pitch. The horizontal lens pitch is 5 times bigger than the subpixel pitch, and the vertical lens pitch is five times bigger than the pixel pitch. Although this system looks like the usual slanted lenticular display, the lens pitch and the slanted angle are different from an ordinary slanted lenticular display. To generate full-color 3D image, the horizontal lens pitch must be 4.5 times bigger than the subpixel pitch. Furthermore, the slanted angle must be arctangent of 6, so that the structure is repeated every two lines vertically[1]. However, in EyeFly 3D, the horizontal lens pitch is 5 times bigger than the subpixel pitch and the structure is repeated in every vertical line, Therefore, the EyeFly 3D system is optically 4-view and one pixel is divided into two of the same size parts by the lens border. Furthermore, 3 subpixels form the righteye view and 2 subpixels form the left-eye view. This optical 4-view system generates only 2-view to enhance the result resolution of the 3D image. EyeFly 3D system also offers a real-time pixel mapping application called EyeFly 3D Img for sideby-side input images Although this unbalance between the left-eye view and the right-eye view causes an unbalance between the two viewing zones, the EyeFly 3D system can fully utilize the intensity of the display panel. The EyeFly 3D system has several weak points compared to an ordinary slanted lenticular display. It only provides two views, forms an unbalanced viewing zone, and has a bigger crosstalk because the lens border is not located at the black matrix region due to a specific angle of slant.however, it is because of this specific angle that the EyeFly 3D system can provide a 3D image for Figure 2: Schematic diagram of new changed crosstalk-reduced dual-mode mobile 3D display: (a) representation mode and (b) landscape mode. However in portrait mode, the viewing zone gets narrower. Since the subpixel pitch and the lens pitch in portrait mode are three times smaller than those in landscape mode, the viewing zone is also three times narrower from the same observing distance. Nevertheless, the EyeFly 3D system repeatedly forms a left-eye viewing zone and a righteye viewing zone because the lens pitch is much smaller than lens thickness Therefore, flipped subpixels form periodic viewing zones so that the observer can see the 3D image not only in landscape mode but also in portrait mode. Since 3 subpixels form the right-eye view and 2 subpixels form the lefteye view, the ratio of the right-eye viewing zone to the left-eye viewing zone is 3 to 2. Although the EyeFly 3D system can provide 3D images in both modes with this clever method, it has its weak points especially, the degradation of the 3D image quality due to the necessary specific angle of slant and the crosstalk it creates. In a portrait mode, crosstalk problem is even more severe because of a narrower viewing zone. The horizontal intensity Available Online@ 292

3 profile of EyeFly 3D system at the observing distance of 30 cm in a portrait mode. The horizontal intensity profile ismeasured with an eye-like device, composed of a display color analyzer CA-210 and a 4 mm diameter aperture which acts as the eye pupil. The interval of the measurement is 5 mm. The red line indicates the horizontal intensity distribution when only the left-eye view is on, while the blue line indicates the opposite situation[1][2]. A left-eye viewing zone and a flipped righteye viewing zone are about 63 mm apart so that they form a stereo-vision to the observer as expected. The crosstalk of the EyeFly 3D system can be obtained from a measured intensity distribution. In a portrait mode, the crosstalk is 26.8%. Although the crosstalk in a landscape mode would be lower than that in a portrait mode, the crosstalk of the EyeFly 3D system is much higher than that of other commercial multi-view devices. It can also cause eye fatigue.. B. Crosstalk-Reduced Dual-Mode Mobile 3D Display Based On Diamond Pentile Display To solve the crosstalk problem in the EyeFly 3D system, they propose a novel dual-mode mobile 3D display system based on a diamond pentile display. Diamond pentile display is a type of various organic light emitting diode display panels, used in Samsung Galaxy S4 (SHV-E330S). The subpixel structure of a diamond pentile display. Since subpixels of a diamond pentile display have a similar size both horizontally and vertically, we expect that a 3D display based on a diamond pentile display can provide 3D images with a similar quality in both portrait and landscape modes. Furthermore, we expect to reduce crosstalk, because a diamond pentile display panel has a larger black matrix than a conventional RGB stripe display panel. By locating lens borders only at the black matrix region, crosstalk can be reduced to much less, compared to conventional slanted lenticular systems. However, to design a 3D display system based on a diamond pentile display, the driving principle of an active matrix OLED display panel should be carefully considered.. Green subpixels are the center of pixels, and horizontally neighboring green subpixels share red and blue subpxiels. To provide a similar quality of 3D images for both modes, a 3D display system containing a display panel and a micro lens array should be symmetric. Therefore, the slant angle of the micro lens array in the proposed system should be 45. Fortunately, a 45 slanted micro lens array can also provide 3D images, if it is with the diamond pentile display. Furthermore, to provide a full-color 3D image, the number of subpixels in one lens should be an odd number. Otherwise, the reconstructed image would be only red/green or blue/green. According to the design conditions mentioned above, To maximize the result resolution of the reconstructed 3D image, we set the number of subpixels in one lens as three, which is the smallest odd number satisfying the conditions. Since mobile multi-view display systems are usually 2-view systems, two subpixels form the right-eye view while one subpixel forms the left-eye view in each lens. As the lens border is located at the black matrix region, the intensity value of crosstalk can be reduced. Since this system is completely symmetric, the proposed 3D display system provides the same viewing zones in both modes, The right-eye viewing zone is twice as broad as the left-eye viewing zone in both modes. This unbalance causes an unbalanced intensity distribution and unintended crosstalk[1]. To verify the proposed system, simulations are performed both with the EyeFly 3D system and the proposed system. The 2-D intensity distribution simulation at the optimum viewing distance of the conventional EyeFly 3D system and the proposed 3D display system based on the ray tracing tool LightTools. The subpixel structure is considered in the simulations, and 100 million rays are used for each simulation. Fig. 2(a) shows 2-D intensity distribution of the EyeFly 3D system at the viewing distance. The left-eye viewing zone and right-eye viewing zone are repeated, and the flipped viewing zone is used in a portrait mode as expected. However, the intensity distribution of the proposed system is symmetric, and the proposed system does not use a flipped viewing zone to form stereo-vision. Furthermore, the contrast between the left-eye view and the right-eye view is greater in the proposed system. Crosstalk can be also estimated from the simulations. The crosstalk of the EyeFly 3D system in a portraitmode is 26.1%, while that of the proposed system is 0.25%. Since the measured crosstalk of the EyeFly 3D system is 26.8% as mentioned in seminar, this simulation is correlated well with the experiment. Therefore, the proposed system can provide high quality 3D images with less crosstalk as expected. III. DEMONSTRATION OF PROPOSED SYSTEM To verify the proposed system, we implement the proposed mobile 3D display system with a parallax barrier film and a diamond pentile display. A Samsung Galaxy S4 (SHV-E330S) mobile phone is Available Online@ 293

4 used as the diamond pentile display panel. The aperture of the parallax barrier is 40 m. Since the principle of a multi-view display using parallax barrier is identical to that of a micro lens array, the specifications of a manufactured parallax barrier are also identical to those of the designed micro lens array. The thickness of the parallax barrier is decided by the observing distance with a simple ray tracing algorithm [1], but the thickness of the cover glass on the pentile display panel is unknown (roughly 1 mm). In our demonstration, the parallax barrier film used is 175 m thick, and has a refractive index of The implemented demonstration system using a manufactured parallax barrier film, a mobile phone diamond pentile display panel, and calibration clamps. For a uniform and robust system, a screen protector glass for mobile phones is used. Since the parallax barrier film does not have any sticky matter inside, additional calibration devices are needed such as calibration. However, the mobile characteristic of the proposed system can be easily obtained with a sticky film like EyeFly 3D, and is not a big issue for the commercial companies. IV. EXPERIMENTAL RESULTS With our implemented system, we present view image experiments. Fig. 1 shows the experiment results of the implemented mobile 3D display system in dual-mode. To verify the viewing zone separation of implemented system, we turned on the left-eye view only and observed the view image separation at the observing plane. The observing plane is 65 cm apart from the demonstration. As we mentioned above, the left-eye view and the right-eye view are repeated with the flipped pixels because the parallax barrier pitch of the film is much smaller than its thickness. This means the left-eye viewing zone and the righteye viewing zone are about 6.5 cm apart, as expected. Furthermore, the light rays clearly converge to the viewpoints in both modes. The viewpoint image is changed clearly as the observing position changes. The intensity profile of the implemented system is also measured to analyze crosstalk. Furthermore, the intensity value of crosstalk is closer to zero in both left-eye view and right-eye view, compared to the EyeFly 3D shown in Fig. 5. It is because the lens border is located at the black matrix region only as shown in Fig. 1. The crosstalk obtained from the measurement of the implemented system is 8.3% in portrait mode and 9.2% in landscape mode. Compared to the crosstalk of the EyeFly 3D system (26.8% in portrait mode), the crosstalk is reduced significantly. Furthermore, the crosstalk value shows that the implemented system provides 3D images of a similar quality in both modes as expected. The crosstalk characteristic of our implemented system is as good as commercial multi-view display devices. The proposed technique can be also developed by using a micro lens array film rather than the simple parallax barrier film. A. Mobile 3D Display Technology 1) Relationship Of Switchable Auto stereoscopic Optical Technologies In this paper, The four main categories of optical components for spatially multiplexed auto stereoscopic displays can be categorized. Barrier technologies include vertical barriers, step barriers and light line type displays, and suffer from low brightness in the 3D mode, poor pixel appearance and diffraction effects which limit the quality of viewing windows, and therefore crosstalk presentation and 3D viewing comfort that can be obtained in such displays. Microlens technologies are best suited to meet the demands of mobile display platforms because of their high optical good organization and superior imaging performance. Microlenses also enable reflective technologies such as transflective LCD to produce high brightness 3D images[1]. Both types of switchable microlens display use a birefringent microlens formed from a liquid crystal (LC) Layer in contact with a surface relief isotropic material. Active lenses 5 rely on switching an electric field across the LC material inside the lens while Polarisation Activated Microlenses TM switch the polarisation state that falls onto a passive (unswitched) birefringent microlens. As described in more detail elsewhere, Polarisation Activated Microlenses are able to demonstrate high contrast and efficiency and have key advantages over Active lenses for mobile platforms including: Improved the image quality in 2D mode High roughness Not inclined to surface pressure skill to make using coating process over large area at low cost No difficulties with the LC cell sealing and handling B. Mobile 3D Content The applications of stereoscopic 3D on mobile phones are primarily directed at entertainment applications including 3D images or wall seminars, MMS, videos and gaming. The main development of the focus for the prototype 3D handset was to enable support for high quality stereoscopic video. Mobile Available Online@ 294

5 devices now regularly support video playback. Developments in mobile TV based on broadcast standards such as Digital Media Broadcast (DMB) as well as the advances in 3G/3.5G networks have positive the more widespread adoption of video capable handsets. These developments provided the necessary framework for the development of a 3D video capability. C. 2D To 3D Translation It is widely acknowledged that a 3D mobile phone must be supported by a range of current and compelling 3D content in order to be commercially successful. DDD has previously published details of its off-line 2D to 3D conversion technologies in this forum. These tools are primarily designed to assist in the identification and tracking of objects in a motion sequence through which a depth map is associated with each image frame. Using depth maps to render virtual stereoscopic images has been described by Harman within the context of home based 3D entertainment. Fehn also proposed Depth-Image-Based-Rendering (DIBR) as the foundation of an advanced 3D TV system. 1) Real-Time Conversion There has been significant interest in the ability to convert 2D content to stereoscopic 3D in real-time (i.e. at video rates). There are a number of reasons why this approach is so attractive: It is opens up a much broader range of stereoscopic content. There is no cost or time delay involved in conversion. Content can be preset and transmitted using existing 2D video formats. Recovering 3D information from a sequence of 2D images is complex, variable and error-prone. The quality of stereoscopic content produced using real-time conversion is therefore generally lower than content converted using off-line (human assisted) translation. Despite this limitation real-time conversion continues to play a significant part in conference the demand for stereoscopic 3D content. DDD developed a real-time conversion process as part of the software bundle for Sharp s AL3D autostereoscopic notebook, providing the means for automatically converting standard DVDs from 2D to 3D [1][2]. The process was based on the automatic improvement of depth information from an image sequence by analyzing the color and motion characteristics of identified objects. To fully realize the bandwidth efficiency of a depth based encoding scheme it is necessary to encode depth data in a separate video stream. However, for the sake of simplicity, depth data is encoded in an asymmetric side-by-side format alongside the 2D video signal. This encoding format provides the best compromise between data fidelity and decoding/rendering overhead for depth encoded content. 2) Content Applications These three encoding formats provide a broad range of options for stereoscopic video on the handset: 1. Original stereo content can be encoded as side-by-side pre-rendered stereo, as described above. This content may have been originated using stereo cameras (either physical or virtual) or by some other 2D to 3D conversion process 2. Depth encoded content can be efficiently transmitted across bandwidth limited networks (such as DMB/DVB-H networks). The depth data may have been created using an offline conversion process or using a depth map camera 3. Real-time conversion can be used to convert any existing 2D content to 3D on the handset It should also be noted that the stereoscopic encoding formats supported on the 3D handset are designed to be open, not proprietary, with the aim of encouraging growth and diversity in the stereoscopic mobile content marketplace. CONCLUSIONS In this paper, I planned a crosstalk-reduced mobile 3D display system providing high quality 3D images in both likeness and landscape modes. I analyzed a conventional commercial mobile 3D display system with simulations and experiments, and I planned a new crosstalk-reduced mobile 3D display system. I designed the micro lens array film and planned a mapping algorithm for the system. To reduce the crosstalk, I adopted the mobile phone with a diamond pentile display panel. I built a demonstration with a parallax barrier film and a smartphone with a diamond pentile display. The implemented system provided 3D images with similar quality in both modes likeness and landscape. The crosstalk of the implemented system was as low as 8.3% in description mode and 9.2% in landscape mode. Acknowledgment I feel great pleasure in submitting this review paper on Reduced Dual-Mode Mobile 3D Display Available Online@ 295

6 Using Crosstalk. I wish to express true sense of gratitude towards my Prof. Priti Subramanium who at very discrete step in study of this paper contributed her valuable guidance and help me to solve every problem that arose. I would wish to thank our H.O.D., Prof. D. D. Patil for opening the doors of the knowledge towards the realization of the paper. Most likely I would like to express my sincere gratitude towards my family for always being there when I needed them the most. With all gratitude and respect, I would like to thank all the people teachers, who helped me directly or indirectly. I owe my all success to them, and special thanks to all authors writers by whose this paper is referred by me. References [1]. Jonghyun Kim, Chang-Kun Lee, Youngmo Jeong, Changwon Jang, Jong-Young Hong, Wonjun Lee,Yoon-Cheol Shin, Jung-Hoon Yoon, and Byoungho Lee, Fellow, IEEE journal of display technology, vol. 11, no. 1, january 2015 [2]. Michael A. Weissman, Andrew J. Woods, A simple method for measuring crosstalk in stereoscopic displays in Proceedings of SPIE Stereoscopic Displays and Applications XXII, Vol. 7863, (2011). Available Online@ 296