Autostereoscopy

The Nintendo 3DS uses parallax barrier autostereoscopy to display a 3D image.

Autostereoscopy is any method of displaying stereoscopic images (adding binocular perception of 3D depth) without the use of special headgear or glasses on the part of the viewer. Because headgear is not required, it is also called "glasses-free 3D" or "glasses-less 3D". The technology also includes two broad approaches used in some of them to accommodate motion parallax and wider viewing angles: those that use eye-tracking, and those that display multiple views so that the display does not need to sense where the viewers' eyes are located.^[1] Examples of autostereoscopic displays include parallax barrier, lenticular, volumetric, electro-holographic, and light field displays.

Technology

Many organizations have developed autostereoscopic 3D displays, ranging from experimental displays in university departments to commercial products, and using a range of different technologies.^[2] The method of creating autostereoscopic 3D using lenses was mainly developed by Reinhard Boerner at the Heinrich Hertz Institute (HHI) in Berlin from 1985.^[3] The HHI was already presenting prototypes of single-viewer displays in the 1990s. Nowadays, this technology has been developed further mainly by European companies. One of the best-known 3D displays developed by HHI was the Free2C, a display with very high resolution and very good comfort achieved by an eye tracking system and a seamless mechanical adjustment of the lenses. Eye tracking has been used in a variety of systems in order to limit the number of displayed views to just two, or to enlarge the stereoscopic sweet spot. However, as this limits the display to a single viewer, it is not favored for consumer products.

Currently, most flat-panel solutions employ lenticular lenses or parallax barriers that redirect incoming imagery to several viewing regions at a lower resolution. When the viewer's head is in a certain position, a different image is seen with each eye, giving a convincing illusion of 3D. Such displays can have multiple viewing zones allowing multiple users to view the image at the same time, though they may also exhibit dead zones where only a non-stereoscopic, pseudoscopic, or no image at all can be seen.

Parallax barrier

Comparison of parallax-barrier and lenticular autostereoscopic displays. Note: The figure is not to scale.

Main article: Parallax barrier

The principle of the parallax barrier was independently invented by Auguste Berthier, who published first but produced no practical results,^[4] and by Frederic E. Ives, who made and exhibited the first known functional autostereoscopic image in 1901.^[5] About two years later, Ives began selling specimen images as novelties, the first known commercial use. Nearly a century later, Sharp developed the electronic flat-panel application of this old technology to commercialization, briefly selling two laptops with the world's only 3D LCD screens.^[6] These displays are no longer available from Sharp but still being manufactured and further developed from other companies like Tridelity and SpatialView. Similarly, Hitachi has released the first 3D mobile phone for the Japanese market under distribution by KDDI.^[7][8] In 2009, Fujifilm released the Fujifilm FinePix Real 3D W1 digital camera, which featured a built-in autostereoscopic LCD display measuring 2.8" diagonal. Nintendo has also implemented this technology on their latest portable gaming console, the Nintendo 3DS.

Integral Photography and Lenticular Arrays

Main articles: Integral imaging and Lenticular lens

The principle of integral photography, which uses a two-dimensional (X-Y) array of many small lenses to capture a 3-D scene, was introduced by Gabriel Lippmann in 1908.^[9][10] Integral photography is capable of creating window-like autostereoscopic displays that reproduce objects and scenes life-size, with full parallax and perspective shift and even the depth cue of accommodation, but the full realization of this potential requires a very large number of very small high-quality optical systems and very high bandwidth. Only relatively crude photographic and video implementations have yet been produced.

One-dimensional arrays of cylindrical lenses were patented by Walter Hess in 1912.^[11] By replacing the line and space pairs in a simple parallax barrier with tiny cylindrical lenses, Hess avoided the light loss that dimmed images viewed by transmitted light and made prints on paper unacceptably dark.^[12] An additional benefit was that the position of the observer was less restricted, as the substitution of lenses was geometrically equivalent to narrowing the spaces in a line-and-space barrier.

Philips solved a significant problem with these displays in the mid-1990s by slanting the cylindrical lenses with respect to the underlying pixel grid.^[13] Philips produced its WOWvx line, based on this idea, until 2009, running up to a 2160p resolution of 3840×2160 pixel 46 viewing angles.^[14] Lenny Lipton's company, StereoGraphics, produced displays based on the same idea, citing a much earlier patent for the slanted lenticulars. Magnetic3d and Zero Creative have also been involved.^[15] The hardware overlay for iPhone and iPod touch named 3DeeSlide also adopts this technology to convert the standard screen into an auto 3D display.^[16]

Other

Dimension Technologies released a range of commercially available 2D/3D switchable LCDs in 2002 using a combination of parallax barriers and lenticular lenses.^[17][18] SeeReal Technologies has developed a holographic display based on eye tracking.^[19] CubicVue exhibited a color filter pattern autostereoscopic display at the Consumer Electronics Association's i-Stage competition in 2009.^[20][21]

There are a variety of other autostereo systems as well, such as volumetric display, in which the reconstructed light field occupies a true volume of space, and integral imaging, which uses a fly's-eye lens array.

The term automultiscopic display has recently been introduced as a shorter synonym for the lengthy "multi-view autostereoscopic 3D display".^[22]

Sunny Ocean Studios, located in Singapore, has been credited with developing an automultiscopic screen that can display autostereo 3D images from 64 different reference points.^[23]

Tridelity AG, located in Germany, has been credited with developing an auto-stereoscopic display in portrait^[24] format specially designed for the signage market.^[25]

Movement Parallax: Single View vs. Multi-View Systems

Movement parallax refers to the fact that the view of a scene changes with movement of the head. Thus, different images of the scene are seen as the head is moved from left to right, and from up to down.

Many autostereoscopic displays are single-view displays and are thus not capable of reproducing the sense of movement parallax, except for a single viewer in systems capable of eye tracking.

Some autostereoscopic displays, however, are multi-view displays, and are thus capable of providing the perception of left-right movement parallax.^[26] Eight and sixteen views are typical for such displays. While it is theoretically possible to simulate the perception of up-down movement parallax, no current display systems are known to do so, and the up-down effect is widely seen as less important than left-right movement parallax. One consequence of not including parallax about both axes becomes more evident as objects increasingly distant from the plane of the display are presented, for as the viewer moves closer to or farther away from the display such objects will more obviously exhibit the effects of perspective shift about one axis but not the other, appearing variously stretched or squashed to a viewer not positioned at the optimum distance from the display.

See also

• Stereoscopic 3D
• Parallax barrier
• Hologram
• MasterImage 3D
• 2D-plus-depth
• Autostereogram
• Computer stereo vision
• LTPS
• Nintendo 3DS
• Stereo camera
• Stereoscopy, the primary means by which people perceive 3D imagery
• Stereogram, creating 3D perception on printed paper or ordinary monitors
• Volumetric display
• HTC EVO 3D

Notes

1. ^ Dodgson, N.A. (August 2005). "Autostereoscopic 3D Displays". IEEE Computer 38 (8): 31–36. doi:10.1109/MC.2005.252. ISSN 0018-9162. 
2. ^ Holliman, N.S. (2006) (PDF). Three-Dimensional Display Systems. ISBN 0750306467. http://www.dur.ac.uk/n.s.holliman/Presentations/3dv3-0.pdf. 
3. ^ Boerner, R. (1985) (in German). 3D-Bildprojektion in Linsenrasterschirmen. http://www.hhi.fraunhofer.de. 
4. ^ Berthier, Auguste. (May 16 and 23, 1896). "Images stéréoscopiques de grand format" (in French). Cosmos 34 (590, 591): 205–210, 227-233 (see 229-231)
5. ^ Ives, Frederic E. (1902). "A novel stereogram". Journal of the Franklin Institute 153: 51–52. doi:10.1016/S0016-0032(02)90195-X. 
6. ^ "2D/3D Switchable Displays" (PDF). Sharp white paper. http://sharp-world.com/corporate/info/rd/tj4/pdf/4.pdf. Retrieved 2008-06-19. 
7. ^ "Woooケータイ H001 | 2009年 | 製品アーカイブ | au by KDDI". Au.kddi.com. http://www.au.kddi.com/seihin/archive/kishu_archive.html?id=h001. Retrieved 2010-06-15. 
8. ^ "Hitachi Comes Up with 3.1-Inch 3D IPS Display". News.softpedia.com. 2010-04-12. http://news.softpedia.com/news/Hitachi-Comes-Up-With-3-1-inch-3D-IPS-Display-139601.shtml. Retrieved 2010-06-15. 
9. ^ Lippmann, G. (2 March 1908). "Épreuves réversibles. Photographies intégrales". Comptes Rendus de l'Académie des Sciences 146 (9): 446–451. 
10. ^ Frédo Durand, MIT CSAIL. "Reversible Prints. Integral Photographs.". http://people.csail.mit.edu/fredo/PUBLI/Lippmann.pdf. Retrieved 2011-02-17.  (This crude English translation of Lippmann's 1908 paper will be more comprehensible if the reader bears in mind that "dark room" and "darkroom" are the translator's mistaken renderings of "chambre noire", the French equivalent of the Latin "camera obscura", and should be read as "camera" in the thirteen places where this error occurs.)
11. ^ 1128979, Hess, Walter, "Stereoscopic picture" , filed 1 June 1912, patented 16 February 1915. Hess filed several similar patent applications in Europe in 1911 and 1912, which resulted in several patents issued in 1912 and 1913.
12. ^ Benton, Stephen (2001). Selected Papers on Three-Dimensional Displays. Milestone Series. MS 162. SPIE Optical Engineering Press. p. xx-xxi. 
13. ^ van Berkel, Cees (1997). "Characterisation and optimisation of 3D-LCD module design". Prov. SPIE 3012: 179–186. doi:10.1117/12.274456. 
14. ^ "Philips’ 3D HDTV Might Destroy Space-Time Continuum, Wallets | Gadget Lab". Wired.com. http://www.wired.com/gadgetlab/2008/10/philips-3d-hdtv/. Retrieved 2010-06-15. 
15. ^ "xyZ 3D Displays - Autostereoscopic 3D TV - 3D LCD - 3D Plasma - No Glasses 3D". Xyz3d.tv. http://www.xyz3d.tv. Retrieved 2010-06-15. 
16. ^ http://www.spatialview.com/3deecentral/
17. ^ Smith, Tom (2002-06-14). "Review : Dimension Technologies 2015XLS". BlueSmoke. http://www.bluesmoke.net/viewArticle.cgi?id=r56. Retrieved 25 March 2010. 
18. ^ McAllister, David F. (February 2002). "Stereo & 3D Display Technologies, Display Technology". In Hornak, Joseph P. (Hardcover). Encyclopedia of Imaging Science and Technology, 2 Volume Set. 2. New York: Wiley & Sons. pp. 1327–1344. ISBN 978-0-471-33276-3. http://research.csc.ncsu.edu/stereographics/wiley.pdf. 
19. ^ Ooshita, Junichi (2007-10-25). "SeeReal Technologies Exhibits Holographic 3D Video Display, Targeting Market Debut in 2009". TechOn!. http://techon.nikkeibp.co.jp/english/NEWS_EN/20071025/141312/. Retrieved 23 March 2010. 
20. ^ "CubicVue LLC : i-stage". I-stage.ce.org. 1999-02-22. http://i-stage.ce.org/?page_id=457. Retrieved 2010-06-15. 
21. ^ Heater, Brian (2010-03-23). "Nintendo Says Next-Gen DS Will Add a 3D Display". PC Magazine. http://www.pcmag.com/article2/0,2817,2361691,00.asp. 
22. ^ Tomas Akenine-Moller, Tomas (2006). Rendering Techniques 2006. A K Peters, Ltd.. pp. 73. ISBN 2006. http://books.google.com/?id=KPZkX5t9170C&pg=PA73&dq=automultiscopy&q. 
23. ^ Pop, Sebastian (2010-02-03). "Sunny Ocean Studios Fulfills No-Glasses 3D Dream". Softpedia. http://news.softpedia.com/news/Sunny-Ocean-Studios-Fulfills-No-Glasses-3D-Dream-133931.shtml. 
24. ^ "Autostereoscopic 3D display in portrait format". tridelity.com. 2010-07-21. http://www.tridelity.com. 
25. ^ Keelaha, A. (2011-03-21). "Tridelity is growing in height". Signageinfo. http://www.signageinfo.com/2011/03/tridelity-3d-is-growing-in-height. 
26. ^ Dodgson, N.A.; J. R. Moore, S. R. Lang (1999). "Multi-View Autostereoscopic 3D Display" (pdf). IEEE Computer 38 (8): 31–36. doi:10.1109/MC.2005.252. ISSN 0018-9162. http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.42.7623. 

• Benton, Steven A., ed (2001). Selected Papers on Three-Dimensional Displays. SPIE Milestone Series MS 162. SPIE. ISBN 0-8194-3893-6. 

External links

• 3D International
• VisuMotion
• Explanation of 3D Autostereoscopic Monitors
• Overview of different Autostereoscopic LCD displays
• Rendering for an Interactive 360º Light Field Display, a demonstration of Autostereoscopy using a spinning mirror, a holographic diffuser, and a high speed video projector demonstrated at SIGGRAPH 2007
• Behind-the-scenes video about production for autostereoscopic displays