3D Techniques

3D Techniques Univ.Prof. Dr.-Ing. Markus Rupp LVA 389.141 Fachvertiefung Telekommunikation (LVA: 389.137 Image and Video Compression) Last change: Jan 20, 2020 Outline • Binocluar Vision • Stereo Images: From first approaches to standardisation • 3D TV Univ.-Prof. Dr.-Ing. Markus Rupp 2 So far we did only this… This is an eye-pad not an IPad Binocular vision • Binocular vision is vision in which both eyes are used together. The word binocular comes from two Latin roots, bini for double, and oculus for eye.[1] Having two eyes confers at least four advantages over having one. First, it gives a creature a spare eye in case one is damaged. Second, it gives a wider field of view. For example, humans have a maximum horizontal field of view of approximately 200 degrees with two eyes, approximately 120 degrees of which makes up the binocular field of view (seen by both eyes) flanked by two uniocular fields (seen by only one eye) of approximately 40 degrees. [2] Third, it gives binocular summation in which the ability to detect faint objects is enhanced.[3] Fourth it can give stereopsis in which parallax provided by the two eyes' different positions on the head give precise depth perception.[4] Such binocular vision is usually accompanied by singleness of vision or binocular fusion, in which a single image is seen despite each eye's having its own image of any object.[4] Binocular vision • Some animals, usually prey animals, have their two eyes positioned on opposite sides of their heads to give the widest possible field of view. Examples include rabbits, buffaloes, and antelopes. In such animals, the eyes often move independently to increase the field of view. Even without moving their eyes, some birds have a 360-degree field of view. • Other animals, usually predatory animals, have their two eyes positioned on the front of their heads, thereby allowing for binocular vision and reducing their field of view in favour of stereopsis. Examples include humans, eagles, wolves, and snakes. • In animals with forward-facing eyes, the eyes usually move together. The field of view of a pigeon compared to that of an owl. Stereoscopy • Stereoscopy (also called stereoscopic or 3-D imaging) refers to a technique for creating or enhancing the illusion of depth in an image by presenting two offset images separately to the left and right eye of the viewer. Both of these 2-D offset images are then combined in the brain to give the perception of 3-D depth. Three strategies have been used to accomplish this: have the viewer wear eyeglasses to combine separate images from two offset sources, have the viewer wear eyeglasses to filter offset images from a single source separated to each eye, or have the lightsource split the images directionally into the viewer's eyes (no glasses required; known as Autostereoscopy). Camera History • The first photography was taken by Joseph Nicéphore Nièpce in 1826 by a so called Heliografie-method. In 1837 Louis Jacques Mandé Daguerre improved the method, developing the films by mercury steam (Quecksilber) and final fixation in a hot salt solution (Kochsalzlösung) or normal temperatured Natriumthiosulfatlösung. The so obtained pictures were all on copper plates named Daguerreotypien. In 1835 the Englishman William Fox Talbot developed the Negativ-Positiv- method. Univ.-Prof. Dr.-Ing. Markus Rupp 8 Camera History • Constanze Mozart, wife of Wolfgang Amadeus Mozart, at 78 years of age, pictured front left in black 2 years before her death. (Her maiden name was Weber). Bavarian composer Max Keller is seated center front, and to his right is his wife Josefa. From left to right in rear: family cook, Philip Lattner (Keller's brother in law), Keller's daughters Luise and Josefa. The print is a 19th century copy of the original daguerrotype photograph taken October 1840, at the home of composer Max Keller. Univ.-Prof. Dr.-Ing. Markus Rupp 9 Stereoscopy • Stereoscopy is the enhancement of the illusion of depth in a photograph, movie, or other two-dimensional image by presenting a slightly different image to each eye, and thereby adding the first of these cues (stereopsis) as well. It is important to note that the second cue is still not satisfied and therefore the illusion of depth is incomplete. • Many 3D displays use this method to convey images. It was first invented by Sir Charles Wheatstone in 1838.[2][3] • Wheatstone originally used his stereoscope (a rather bulky device)[4] with drawings because photography was not yet available, yet his original paper seems to foresee the development of a realistic imaging method[5]: Sir Charles Wheatstone in 1838 • “For the purposes of illustration I have employed only outline figures, for had either shading or colouring been introduced it might be supposed that the effect was wholly or in part due to these circumstances, whereas by leaving them out of consideration no room is left to doubt that the entire effect of relief is owing to the simultaneous perception of the two monocular projections, one on each retina. But if it be required to obtain the most faithful resemblances of real objects, shadowing and colouring may properly be employed to heighten the effects. Careful attention would enable an artist to draw and paint the two component pictures, so as to present to the mind of the observer, in the resultant perception, perfect identity with the object represented. Flowers, crystals, busts, vases, instruments of various kinds, &c., might thus be represented so as not to be distinguished by sight from the real objects themselves.”[2] Univ.-Prof. Dr.-Ing. Markus Rupp 11 1860: stereoscopic postcards became a fashion But you need a „viewer“ Not so much different today • Anaglyph (red and blue) • Also shutter glasses, polarisation glasses… Autostereoscopy • Autostereoscopy is any method of displaying stereoscopic (3D) images 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". The technology includes two broad classes of displays: those that use head-tracking to ensure that each of the viewer's two eyes sees a different image on the screen, and those that display multiple views so that the display does not need to know where the viewers' eyes are directed. Examples of autostereoscopic displays include parallax barrier, lenticular, volumetric, electro-holographic, and light field displays. • Some autostereoscopic displays are also capable of recreating a perception of movement parallax, which is not possible with any of the active or passive technologies discussed above. "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. • This is the method used by the Nintendo 3DS video game system and the Optimus 3D and LG Thrill by cellphone manufacturer LG Electronics MobileComm, HTC EVO 3D. Parallax Barrier • The principle of the parallax barrier has been invented by Auguste Berthier[4]in 1896 but was later popularized by the independent invention by Frederic E. Ives.[5] Sharp developed the 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 • The principle of integral photography, which uses a two-dimensional array of lenslets to capture a 3-D scene, is usually attributed to Gabriel Lippmann in his paper of 1908.[9][10] Lenticular arrays were invented later; according to Benton, "[i]n an attempt to overcome the brightness limitations of raster barrier screens, Hess, [in a patent filed in 1913,[11]] showed that tiny cylindrical lenslets could be used for the same purpose."[12] Pierre Allio produced some of the first patents in lenticular displays in the mid-1980s. Philips solved a significant problem with these displays in the mid-1990s by slanting the lenticular 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] Autostereoscopic displays • 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.

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