A Study of Immersive Display Technologies

Transcription

1 Smart Computing Review, vol. 2, no. 3, June Smart Computing Review A Study of Immersive Display Technologies Tae-Sub Chung Dept. of Broadcasting & Digital Media, Chungwoon University / San29, Namjang-ri, Hongsung, Chungnam , South Korea / ggam98@chungwoon.ac.kr Received April 3, 2012; Revised May 29, 2012; Accepted June 5, 2012; Published June 30, 2012 Abstract: This study details the different kinds of immersive media and immersive display techniques. The advancement of displays is actually related to screen resolution. The advanced definition as well as the development of display sizes by resolution leads to a move immersive environment for audiences. Maintaining a good resolution needs to happen alongside the development of displays. Therefore, this study studies display sizes according to the resolution of each type of display and the projection methods according to display type. It also discusses display technology according the production method of immersive media. Keywords: Immersive Media, Display Technology, Immersive Display, Immersive Screen Introduction A n immersive image is an important factor to all viewers. Though various kinds of displays for immersive images have been developed, most are suitable for being seen through a large display. Especially in the age of 3D images, the appearance of immersive media to save time and to lower the price of 3D imaging can provide a variety according to the expansion and oversize trend of displays. But as immersive images have a limited consumption market, Korean companies are reluctant to produce them. Also, display sizes are increasing. Various sizes of display from that of less SDclass (720x 480) to the large display for IMAX were created to create an immersive feeling for a viewer. However, the image production level is currently unable to create an immersive feeling, and the image production process in general is lagging behind the advancement of the display industry. Immersive media is the image method of seeing the real world the most actually without the need to wear special glasses. Recently the demand for the real-feeling media with the development of various types of displays is increased, and a new market is formed for it. In the past, real-feeling media was different from 3D image technology, but the market has not expanded because of the limits of displays. Currently, the advancement of the display industry provides a chance to cast new light on immersive media as much as 3D images, and such technological advancements can provide an environment to realize immersive media through curved-form displays. When a flat image projects on a curved screen, the image becomes warped. To solve this problem, images need to be optimized for a curved screen by developing a separate image format and renderer for curved screen image content. So this study will investigate displays and display types according to content types and projection types to realize immersive media. DOI: /smartcr

2 232 Chung: A Study on Immersive Display Technologies This study will also investigate a display to apply for immersive media. Additionally, this study will describe the design of an algorithm of exploration to adjacent images and its pattern composition, and research about image content production for current flat displays. Based on the above research, this study will find the problems in the production of environment maps for immersive displays, and seek ways to correct images and compare the differences between the production for immersive displays and current production. This study is laid out as follows. Section 2 will discuss the image content for immersive displays and the display types according to projection types. Section 3 will describe the applied experiment method for immersive displays and its results. Finally, Section 4 will discuss the conclusion and future tasks. Immersive Display As a next-generation media pursuing the best reproduction of reality, Immersive Media is a technology that can be utilized in computer graphics, displays, industrial applications, broadcasting, movies, and games, because immersive media can provide much better expressive ability, cleaner definition, and a more real feeling than currently used media [1]. Immersive Media is a display that can be seen from various angles. Especially, immersive virtual environments can be used in the digital art field. A digital artist can do work in various ways while maximizing the audience s visual immersive feeling [2]. However, the production condition or methods of image content according to the definition and the used display type is important. Therefore this study will research about the possibility to develop immersive media technology through the advancement of displays according to immersive media s features. Display Types According to Content Types A display used as a tool delivering images and various meanings can be recognized as a medium. The media evolves in various ways. Especially, the advancement of displays leads to the development of an information-oriented society through media evolution. This means that even an image or text with the same meaning can be changed through the advancement of displays. In early times, the general display size was SD with a 640 x 480 resolution. From that time, the display size of Super High Vision at 7680x 4320 appeared. The comparison data of display sizes is shown in Table 1. General HD Ultra HD Table 1. Video resolution by display type Classification Definition Ratio SD 640 X X 480 HD 1280 X 720 Full HD 1920 X 1080 QFHD 3840 X 2160 Digital Cinema 4096 X 2160 Super High Vision 7680 X :3 16:9 Ultra HD display means a display boasting as much as 4 times or 16 times the definition of Full HD display, as you can see in Figure 1 [3]. As LCD and PDP screens are larger than previous screens, the need for the development of Ultra HD displays is increased. Because the higher resolution of a screen, the greater the immersive effect, and the more immersive effect leads to maximum realism [4]. The appearance of flat screen TVs help in reducing the burden on the CRT-formed TV s size. Especially, customer awareness on a large screen and the maximization of resolution according to screen size stimulates the consumers. That is because the viewing angle widens because of the optimal viewing distance. For the HD TV, the optimal viewing distance and the viewing angle in the horizontal direction are 3.0H and 30, respectively. For a Digital Cinema, the values are 1.5H and 55. For Super High Vision, the values are 0.75H and 100, respectively.

3 Smart Computing Review, vol. 2, no. 3, June Figure 1. Comparison of video resolutions by display Classification HDTV Digital Cinema Super High Vision Viewing Angle in Horizontal Direction Optimal Viewing Distance H 1.5H 0.75H Figure 2. Differences of viewing angles and optimal viewing distance according to screen size [5] Display Types According to Projection Types In Immersive Media, there are two projection types: front projection and back projection. Front projection is a general type of projection, enabling the reproduction of images on goggles, screens, and immersive monitors. Back projection screen types can be classified into dome type to see the maximum-sized screen, screen type adjusting for audience viewing angle, and the CAVE type. The immersive screen classifies the wide screen type into the Flat Wall and the Cylindrical, and the dome screen type into the Sphere and the Room. Currently NEC s CRV43 (288x 900) has been released as a commercial

4 234 Chung: A Study on Immersive Display Technologies screen product, and its appearance is a general monitor screen. A projection-type display changes a screen form according to the projection type. So projection-type displays can be classified as in Table 2. Table 2. Classification of Projection-Type Displays [6] Classification Projection Types Merits Drawbacks Desks Type Mirror Reflection Enabled to use work objects like it is on the hand. High loss rate of screen Flat Wall Front or Back Less distortion at the border line. Able to be used by majority. Changing immersive environment according to the observer s location Projection Type Display Cylindrical Spherical Front Reflection Environment in which majority can be immersed. Environment that majority can be immersed. - Creation of shadows - Problems in treating the boundary point using a multi channel. - Need for the base of installment structure - Creation of shadow - Problems in treating the boundary point at using a multi channel. - Need for the base of installment structure CAVE Back Projection - Optimal immersive environment - Enable the majority s immersion - Provision of wide visual field - Provision of progressive vision - Expensive - Limited number of concurrent users - Need for the base of installment structure Immersive Media s production types are dependent on the ways projected on a screen. Table 3 shows the differences of production methods according to screen types using the image of Figure 3. The photos in Figure 3 are the used in producing a panorama. With this source, the images in Table 4 can be gotten. The panorama was produced with Microsoft Image Composite Editor (ICE) [6]. This program has drawbacks, in that it needs many pieces of images and should set the order for managing and producing images when producing a video. Therefore the image production methods are changed depending on the display method. If there is a top like Figure 4, the images of the top and bottom should be produced together if the images are produced for the CAVE type. These images can be used in current flat displays. Representative services applying such image production methods are Google Maps Road View and Daum s Road View. These services can be seen as an immersive image type, and such images can be produced in a similar method to the above production method. But when moving in all cardinal directions (up & down, left & right), some problems about the images and the boundary between images appear

5 Smart Computing Review, vol. 2, no. 3, June Figure 3. Production images according to screen types [7]. Table 3. Production images according to screen types Classification Screen Type Image Cylindrical Wide Monitor Cylinder Type(V) Flat Wall Flat Type Cylinder Type (H) Spherical Dome Type Sphere Type CAVE BOX Type Perspective

6 236 Chung: A Study on Immersive Display Technologies Figure 4. Dome type fish-eye image. Experiment Setting the Experimental Conditions The experiment for this study was conducted under the same condition as that of Table 4. Table 4. Experiment Environment Operation System Development Tool Use Library & SDK Windows XP/7 MS Visual Studio C SP1 MS DirectX9(June 2010) Irrlicht Engine ( IrrKlang Sound SDK ( Haptic tool-related library To utilize multiple viewpoints, the camera was installed using the 3D Studio Max program like that of Figure 5. The video projected on the 110 ~360 curve screen had to realize the environment map by installing multiple cameras, and the master formats in various forms could finally be output. That is the necessary part for a CG work for the environment production, and the combination should be composed through that. Through that, the environment map needed for the image to be projected on an immersive-type display should be arranged. The arrangement of the environment for dome-type displays and wide-type monitors are different. The difference of is caused by the fact that the dome-type display should have the screen over the head and the screen on the bottom, but the wide-type monitor does not need to show the screen over the head and the screen on the bottom. Figure 6 shows the arrangement of environment maps. The dome-type display needs all 6 sides, but the wide-type display does not need the Top and Bottom screens. Although the production of wide-type display seems to be simple, its immersion level tends to be low.

7 Smart Computing Review, vol. 2, no. 3, June Figure 5. Multi view-point camera (front, back-side, left, right, upper and downward-6view) Image Correction by Experiment Figure 6. Production process of environment map For the images corrected by CG, it is often difficult to set the boundary images recorded by one camera and by multiple cameras. Without correcting images, the intermediate stage is traced through the overlap of images. For a panorama recording, the overlapped part is traced and when the completed image is found, then the image is used (Figure 7). Figure 7. Examples of image screens including the recording overlaps Figure 8 shows the process of completing one image through tracing the over parts of the original image. The image connected to the front side should be overlapped with the images of right and left sides. That occupies a large part of the

8 238 Chung: A Study on Immersive Display Technologies image loss rate. However, the part is necessary for an accurate image, so the image should be produced through highdefinition video. Figure 8. Production results of immersive content Conclusion This study describes the future of displays becoming larger through the change of screen size and details display appearances and production types according to the kinds of immersive media. There are largely 3 production types for immersive media: the image type according to projection, the cylinder type, and the sphere type. It is found that the production methods are different according to the 3 display types. For the variety of immersive media, if we research the immersion further and add the immersive feeling of 3D video through a small display size, it will produce better displays. Especially, the investigator thinks that video in the HD age will accompany the advancement of displays. Also, the content production for immersive displays will enable to produce a theater for a 5-sense experience. Especially for video that doesn t require special glasses, it is expected that the immersive feeling will be higher than the immersive feeling at seeing 3D video. For this purpose, there should be various trials in both the academic world and industry. References [1] NHN Co., Immersive Media, [2] C.-R. Ryu, Development of immersive-type virtual environment system for 3D digital art, High-Tech Video Graduate School, Chungang University, [3] C.-H. Lee, Ultra HD display development trend & suggestions, SERI Economic Focus, vol. 200, Samsung Economics Research Institute, [4] K. Masaoka, M. Emoto, M. Sugawara, The sense of presence when viewing super hi-vision images, The Jounal of The Institute of Image Information and Television Engineers, vol. 61, no, 5, pp , Article (CrossRef Link) [5] Ultrahigh Definition TV, NHK/ digital, [6] Microsoft Research, Image Composite Editor, [7] The sky picture like taken with fish-eye lens,

9 Smart Computing Review, vol. 2, no. 3, June Tae-Sub Chung received his BA in Industrial Design from Seoul National University of Science & Technology, Seoul, Korea, in 1993, his MA in Product Design from Hongik University, Seoul, Korea, in 1999, and his PhD completion in Visual Supervisors from Dongguk University, Seoul, Korea, in Currently he is an Assistant Professor in Chungwoon University, Chungnam, Korea. His research interests include computer graphics, broadcasting CG, broadcasting editing, and image aesthetics. Copyrights 2012 KAIS