Stereoscopy is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word stereoscopy derives from Greek, Modern στερεός (stereos), meaning 'firm, solid', and σκοπέω (skopeō), meaning 'to look, to see'. Any stereoscopic image is called a stereogram. Originally, stereogram referred to a pair of stereo images which could be viewed using a stereoscope.
A stereoscope is a device for viewing a stereoscopic pair of separate images, depicting left-eye and right-eye views of the same scene, as a single three-dimensional image.
An autostereogram is a single-image stereogram (SIS), designed to create the visual illusion of a three-dimensional (3D) scene from a two-dimensional image. In order to perceive 3D shapes in these autostereograms, one must overcome the normally automatic coordination between accommodation (focus) and horizontal vergence. The illusion is one of depth perception and involves stereopsis: depth perception arising from the different perspective each eye has of a three-dimensional scene, called binocular parallax.
The Pulfrich effect is a psychophysical percept wherein lateral motion of an object in the field of view is interpreted by the visual cortex as having a depth component, due to a relative difference in signal timings between the two eyes.
A stereo display is a display device capable of conveying depth perception to the viewer by means of stereopsis for binocular vision.
A pseudoscope is a binocular optical instrument that reverses depth perception. It is used to study human stereoscopic perception. Objects viewed through it appear inside out, for example: a box on a floor would appear as a box shaped hole in the floor.
An active shutter 3D system is a technique of displaying stereoscopic 3D images. It works by only presenting the image intended for the left eye while blocking the right eye's view, then presenting the right-eye image while blocking the left eye, and repeating this so rapidly that the interruptions do not interfere with the perceived fusion of the two images into a single 3D image.
A polarized 3D system uses polarization glasses to create the illusion of three-dimensional images by restricting the light that reaches each eye.
Anaglyph 3D is the name given to the stereoscopic 3D effect achieved by means of encoding each eye's image using filters of different colors, typically red and cyan. Anaglyph 3D images contain two differently filtered colored images, one for each eye. When viewed through the "color-coded" "anaglyph glasses", each of the two images reaches the eye it's intended for, revealing an integrated stereoscopic image. The visual cortex of the brain fuses this into the perception of a three-dimensional scene or composition.
Stereopsis is a term that is most often used to refer to the perception of depth and 3-dimensional structure obtained on the basis of visual information deriving from two eyes by individuals with normally developed binocular vision. Because the eyes of humans, and many animals, are located at different lateral positions on the head, binocular vision results in two slightly different images projected to the retinas of the eyes. The differences are mainly in the relative horizontal position of objects in the two images. These positional differences are referred to as horizontal disparities or, more generally, binocular disparities. Disparities are processed in the visual cortex of the brain to yield depth perception. While binocular disparities are naturally present when viewing a real 3-dimensional scene with two eyes, they can also be simulated by artificially presenting two different images separately to each eye using a method called stereoscopy. The perception of depth in such cases is also referred to as "stereoscopic depth".
A vectograph is a type of stereoscopic print or transparency viewed by using the polarized 3D glasses most commonly associated with projected 3D motion pictures.
Autostereoscopy is any method of displaying stereoscopic 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" or "glassesless 3D". There are two broad approaches currently used to accommodate motion parallax and wider viewing angles: eye-tracking, and multiple views so that the display does not need to sense where the viewers' eyes are located.
A parallax barrier is a device placed in front of an image source, such as a liquid crystal display, to allow it to show a stereoscopic or multiscopic image without the need for the viewer to wear 3D glasses. Placed in front of the normal LCD, it consists of an opaque layer with a series of precisely spaced slits, allowing each eye to see a different set of pixels, so creating a sense of depth through parallax in an effect similar to what lenticular printing produces for printed products and lenticular lenses for other displays. A disadvantage of the method in its simplest form is that the viewer must be positioned in a well-defined spot to experience the 3D effect. However, recent versions of this technology have addressed this issue by using face-tracking to adjust the relative positions of the pixels and barrier slits according to the location of the user's eyes, allowing the user to experience the 3D from a wide range of positions. Another disadvantage is that the horizontal pixel count viewable by each eye is halved, reducing the overall horizontal resolution of the image.
Teleview was a system for projecting stereoscopic motion pictures invented by Laurens Hammond, best known as the inventor of the Hammond organ. It made its public debut on 27 December 1922 at the Selwyn Theatre in New York City, the only theater ever equipped with the system. The program included several short films, a live presentation of projected 3D shadows, and the 95-minute feature film M.A.R.S., later re-released in 2D as Radio-Mania.
Phantograms, also known as Phantaglyphs, Op-Ups, free-standing anaglyphs, levitated images, and book anaglyphs, are a form of optical illusion. Phantograms use perspectival anamorphosis to produce a 2D image that is distorted in a particular way so as to appear, to a viewer at a particular vantage point, three-dimensional, standing above or recessed into a flat surface. The illusion of depth and perspective is heightened by stereoscopy techniques; a combination of two images, most typically but not necessarily an anaglyph. With common (red–cyan) 3D glasses, the viewer's vision is segregated so that each eye sees a different image.
The Fujifilm FinePix Real 3D W series is a line of consumer-grade digital cameras designed to capture stereoscopic images that recreate the perception of 3D depth, having both still and video formats while retaining standard 2D still image and video modes. The cameras feature a pair of lenses, and an autostereoscopic display which directs pixels of the two offset images to the user's left and right eyes simultaneously. Methods are included for extending or contracting the stereoscopic baseline, albeit with an asynchronous timer or manually depressing the shutter twice. The dual-lens architecture also enables novel modes such as simultaneous near and far zoom capture of a 2D image. The remainder of the camera is similar to other compact digital cameras.
3D Vision is a stereoscopic gaming kit from Nvidia which consists of LC shutter glasses and driver software which enables stereoscopic vision for any Direct3D game, with various degrees of compatibility. There have been many examples of shutter glasses. Electrically controlled mechanical shutter glasses date back to the middle of the last century. LCD shutter glasses appeared in the 1980s, one example of which is Sega's SegaScope. This was available for Sega's game console, the Master System. The NVIDIA 3D Vision gaming kit introduced in 2008 made this technology available for mainstream consumers and PC gamers.
Stereoscopic depth rendition specifies how the depth of a three-dimensional object is encoded in a stereoscopic reconstruction. It needs attention to ensure a realistic depiction of the three-dimensionality of viewed scenes and is a specific instance of the more general task of 3D rendering of objects in two-dimensional displays.
Stereo photography techniques are methods to produce stereoscopic images, videos and films. This is done with a variety of equipment including special built stereo cameras, single cameras with or without special attachments, and paired cameras. This involves traditional film cameras as well as, tape and modern digital cameras. A number of specialized techniques are employed to produce different kinds of stereo images.
The Van Hare Effect is a 3D stereoscopic viewing technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision using psychophysical percepts. The Van Hare Effect creates the illusion of dimensionality, rather than actual dimensionality in the subject being viewed. The Van Hare Effect is achieved by employing the stereoscopic cross-eyed viewing technique on a pair of identical images placed side-by-side. In doing so, it artificially tricks the human brain and optical center into seeing depth in what is actually a two-dimensional, non-stereoscopic image. The illusion of depth is interesting in that even if the image pair is not itself originally stereoscopic, the brain perceives it as if it is.
