Stereopsis (from stereo meaning solidity, and opsis meaning vision or sight) is the process in visual perception leading to perception of stereoscopic depth. In turn, stereoscopic depth is the sensation of depth that emerges from the fusion of the two slightly different projections of the world on the two retinas. The difference between the two eyes’ images, which is a result of the eyes' horizontal separation, is usually referred to as binocular disparity or retinal disparity. The fact that this binocular disparity is interpreted by the brain as depth was first discovered by the English genius Charles Wheatstone and described by him in a classic paper^[1] published in 1838: ”… the mind perceives an object of three-dimensions by means of the two dissimilar pictures projected by it on the two retinæ…”, (Wheatstone, 1838). To prove his ideas Wheatstone invented a simple device, which he dubbed a stereoscope. Using his newly invented stereoscope Wheatstone was able to convincingly show that a vivid sense of depth emerges from two completely flat pictures depicting two different projections of the same scene. Visual perception is one of the senses, consisting of the ability to detect light and interpret (see) it as the perception known as sight or naked eye vision. ... This article or section does not cite its references or sources. ... Charles Wheatstone Sir Charles Wheatstone (February 6, 1802 - October 19, 1875) was the British inventor of many innovations including the English concertina the Stereoscope an early form of microphone the Playfair cipher (named for Lord Playfair, the person who publicized it) He was a major figure in the development of... Pocket stereoskop WILD 1985 Old Zeiss pocket stereoscope with original test image Stereo card of a stereoscope in use. ...

History of stereopsis

Stereopsis was first described by Charles Wheatstone in 1838.^[2] He recognized that because each eye views the visual world from slightly different horizontal positions, each eye's image differs from the other. Objects at different distances from the eyes project images in the two eyes that differ in their horizontal positions, giving the depth cue of horizontal disparity, also known as retinal disparity and as binocular disparity. Wheatstone showed that this was an effective depth cue by creating the illusion of depth from flat pictures that differed only in horizontal disparity. To display his pictures separately to the two eyes, Wheatstone invented the stereoscope. Charles Wheatstone Sir Charles Wheatstone (February 6, 1802 - October 19, 1875) was the British inventor of many innovations including the English concertina the Stereoscope an early form of microphone the Playfair cipher (named for Lord Playfair, the person who publicized it) He was a major figure in the development of... | Jöns Jakob Berzelius, discoverer of protein 1838 was a common year starting on Monday (see link for calendar). ... Cue may refer to one of the following. ... Stereopsis (from stereo meaning solidity, and opsis meaning vision or sight) is the process in visual perception leading to perception of stereoscopic depth. ... Stereopsis (from stereo meaning solidity, and opsis meaning vision or sight) is the process in visual perception leading to perception of stereoscopic depth. ... Stereopsis (from stereo meaning solidity, and opsis meaning vision or sight) is the process in visual perception leading to perception of stereoscopic depth. ... This article is about the phenomenon known as an illusion. ... Pocket stereoskop WILD 1985 Old Zeiss pocket stereoscope with original test image Stereo card of a stereoscope in use. ...

Leonardo da Vinci had also realized that objects at different distances from the eyes project images in the two eyes that differ in their horizontal positions, but had concluded only that this made it impossible for a painter to portray a realistic depiction of the depth in a scene from a single canvas. Leonardo chose for his near object a column with a circular cross section and for his far object a flat wall. Had he chosen any other near object, he may have discovered horizontal disparity of its features. His column was one of the few objects that projects identical images of itself in the two eyes. The Mona Lisa Leonardo di ser Piero da Vinci (April 15, 1452 – May 2, 1519) was an Italian polymath: scientist, mathematician, engineer, inventor, anatomist, painter, sculptor, architect, musician, and writer. ...

Stereopsis became popular during Victorian times with the invention of the prism sterescope by David Brewster. This, combined with photography, meant that tens of thousands of stereograms were produced. Queen Victoria (shown here on the morning of her Accession to the Throne, June 20, 1837) gave her name to the historic era. ... David Brewster Sir David Brewster, (December 11, 1781 – February 10, 1868) was a Scottish scientist. ... Photography is the process of making pictures by means of capturing light on a light-sensitive medium, such as a sensor or film. ...

Until about the 1960s, research into stereosis was dedicated to exploring its limits and its relationship to singleness of vision. Researchers included Panum, Hering, Adelbert Ames Jr., and Kenneth N. Ogle. The company is part of Cia. ... Adelbert Ames Adelbert Ames, Jr. ... Kenneth N. Ogle was a scientist of human vision. ...

Also in the 1960s, Bela Julesz invented random-dot stereograms. Unlike previous stereograms, in which each half image showed recognizable objects, each half image of the first random-dot stereograms showed a square matrix of about 10,000 small dots, with each dot having a 50% probability of being black or white. No recognizable objects could be seen in either half image. The two half images of a random-dot stereogram were essentially identical, except that one had a square area of dots shifted horizontally by one or two dot diameters, giving horizontal disparity. The gap left by the shifting was filled in with new random dots, hiding the shifted square. Nevertheless, when the two half images were viewed one to each eye, the square area was almost immediately visible by being closer or farther than the background. Julesz whimsically called the square a cyclopean stimulus after the mythical Cyclops who had only one eye. This was because it was as though we have a cyclopean eye inside our brains that can see cyclopean stimuli hidden to each of our actual eyes. Random-dot stereograms highlighted a problem for stereopsis, the correspondence problem. This is that any dot in one half image can realistically be paired with many same-coloured dots in the other half image. Our visual systems clearly solve the correspondence problem, in that we see the intended depth instead of a fog of false matches. Research began to understand how. Bela Julesz (February 19, 1928_December 31, 2003) was a visual neuroscientist and experimental psychologist in the fields of visual and auditory perception. ... It has been suggested that this article or section be merged into Autostereogram. ... Cyclopean is a descriptor applied to the characteristic wall-building method of the Mycenaean culture. ... Polyphemus the Cyclops. ... Given two or more images of the same 3D scene, taken from different points of view, the correspondence problem is to find a set of points in one image which can be indentified as the same points in another image. ...

Also in the 1960s, Horace Barlow, Colin Blakemore, and Jack Pettigrew found neurons in the cat visual cortex that had their receptive fields in different horizontal positions in the two eyes. This established the neural basis for stereopsis. Their findings were disputed by David Hubel and Torsten Wiesel, although they eventually conceded when they found similar neurons in the monkey visual cortex. In the 1980s, Gian Poggio and others found neurons in V2 of the monkey brain that responded to the depth of random-dot stereograms. Professor Horace Basil Barlow FRS (born December 8, 1921) is a British visual neuroscientist. ... Colin Blakemore is a neurobiologist specialising in vision. ... John Douglas (Jack) Pettigrew (born 1943) is Emeritus Professor of Physiology and Director of the Vision, Touch and Hearing Research Centre at the University of Queensland in Australia. ... Drawing by Santiago Ramón y Cajal of neurons in the pigeon cerebellum. ... Trinomial name Felis catus Linnaeus, 1758 The cat (or domestic cat, house cat) is a small carnivorous mammal. ... Brodmann area 17 (primary visual cortex) is shown in red in this image which also shows area 18 (orange) and 19 (yellow) The visual cortex refers to the primary visual cortex (also known as striate cortex or V1) and extrastriate visual cortical areas such as V2, V3, V4, and V5. ... The receptive field of a sensory neuron is a region of space in which the presence of a stimulus will alter the firing of that neuron. ... David Hunter Hubel (b. ... Torsten Nils Wiesel (b. ... For other uses, see Monkey (disambiguation). ... V2 V2, Japanese musical duo formed by Yoshiki of ex-X Japan and Tetsuya Komuro V2 Records V2 word order, the verb-second word order of Germanic languages Velocity 2, the speed where an aircraft accelerating on a runway must lift-off Visual cortex#V2 area Vatican II or Second...

In the 1990s, Christopher Tyler invented autostereograms, random-dot stereograms that can be viewed without a stereoscope. This led to the popular Magic Eye pictures. In 1979, Dr. Christopher Tyler, a student of Bela Julesz and a visual psychophysicist, combined the theories behind single-image wallpaper stereograms and random-dot stereograms to create the first random-dot autostereogram (also known as single-image random-dot stereogram) which allowed the brain to see 3D shapes from... A random dot autostereogram encodes a 3D scene which can be seen with proper viewing technique. ... Magic Eye is a series of books published by N.E. Thing Enterprises (Renamed in 1996 to Magic Eye Inc. ...

Popular culture

A stereoscope is a device by which each eye can be presented with different images, allowing stereopsis to be stimulated with two pictures, one for each eye. This has lead to various crazes for stereopsis, usually prompted by new sorts of stereoscopes. In Victorian times it was the prism stereoscope (allowing stereo photographs to be viewed), in the 1950s it was red-green glasses (allowing stereo movies to be viewed), in the 1970s it was polarizing glasses (allowing coloured movies to be viewed), and in the 1990s it was Magic Eye pictures (autostereograms). Magic Eye pictures did not require a stereoscope, but relied on viewers using a form of free fusion so that each eye views different images. Pocket stereoskop WILD 1985 Old Zeiss pocket stereoscope with original test image Stereo card of a stereoscope in use. ... Herd behaviour is the term used to describe situations in which the individuals of any particular group react coherently. ... Queen Victoria (shown here on the morning of her Accession to the Throne, June 20, 1837) gave her name to the historic era. ... A sepia-toned photograph taken in England in 1895 U.S. Marines raising the flag on Iwo Jima, February 23, 1945 Peter Leibings photograph of Conrad Schumann leaping over barbed wire into West Berlin on August 15, 1961 Buzz Aldrin salutes the US flag on the surface of the... Stereo card image anaglyphed for red (left eye) and cyan (right eye) filters Anaglyph glasses use color filters to moderate the light reaching each eye to create the illusion of a three diminutional image, an example of stereoscopy. ... Film is a term that encompasses individual motion pictures, the field of film as an art form, and the motion picture industry. ... Polarized glasses create the illusion of three-dimensional images by restricting the light that reaches each eye, and example of stereoscopy. ... Color is an important part of the visual arts. ... Magic Eye is a series of books published by N.E. Thing Enterprises (Renamed in 1996 to Magic Eye Inc. ... A random dot autostereogram encodes a 3D scene which can be seen with proper viewing technique. ...

Geometrical basis for stereopsis

Stereopsis appears to be processed in the visual cortex in binocular cells having receptive fields in different horizontal positions in the two eyes. Such a cell is active only when its preferred stimulus is in the correct position in the left eye and in the correct position in the right eye, making it a disparity detector. The receptive field of a sensory neuron is a region of space in which the presence of a stimulus will alter the firing of that neuron. ... Disparity refers to the difference in images from the left and right eye that the brain uses as a binoculars cue to determine depth or distance of an object. ...

When a person stares at an object, the two eyes converge so that the object appears at the center of the retina in both eyes. Other objects around the main object appear shifted in relation to the main object. In the following example, whereas the main object (dolphin) remains in the center of the two images in the two eyes, the cube is shifted to the right in the left eye's image and is shifted to the left when in the right eye's image. Human eye cross-sectional view. ...

The two eyes converge on the object of attention.
The cube is shifted to the right in left eye's image.	The cube is shifted to the left in the right eye's image.

We see a single, Cyclopean, image from the two eyes' images.

Because each eye is in a different horizontal position, each has a slightly different perspective on a scene yielding different retinal images. Normally two images are not observed, but rather a single view of the scene, a phenomenon known as singleness of vision. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ...

If the images are very different (such as by going cross-eyed, or by presenting different images in a stereoscope) then one image at a time may be seen, a phenomenon known as binocular rivalry. Pocket stereoskop WILD 1985 Old Zeiss pocket stereoscope with original test image Stereo card of a stereoscope in use. ... Binocular rivalry is a phenomenon of visual perception in which perception alternates between different images presented to each eye. ...

The brain gives each point in the Cyclopean image a depth value, represented here by a grayscale depth map.

Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ...

Computer stereo vision

Computer stereo vision, is a part of the field of computer vision. It is sometimes used in mobile robotics to detect obstacles. To meet Wikipedias quality standards, this article or section may require cleanup. ... This article or section does not cite its references or sources. ... It has been suggested that this article or section be merged with robot. ...

Two cameras take pictures of the same scene, but they are separated by a distance - exactly like our eyes. A computer compares the images while shifting the two images together over top of each other to find the parts that match. The shifted amount is called the disparity. The disparity at which objects in the image best match is used by the computer to calculate their distance. Disparity refers to the difference in images from the left and right eye that the brain uses as a binoculars cue to determine depth or distance of an object. ...

For a human, the eyes change their angle according to the distance to the observed object. To a computer this represents significant extra complexity in the geometrical calculations (Epipolar geometry). In fact the simplest geometrical case is when the camera image planes are on the same plane. The images may alternatively be converted by reprojection through a linear transformation to be on the same image plane. This is called Image rectification. Epipolar geometry refers to the geometry of stereo vision. ... In mathematics, a linear transformation (also called linear map or linear operator) is a function between two vector spaces that preserves the operations of vector addition and scalar multiplication. ... Image rectification is a transformation process used to project multiple images onto a common image surface. ...

Computer stereo vision with one camera is called structure from motion. It is well known that the visual system uses motion to extract information about the three-dimensional shape of objects. ...

Computer stereo display

Many attempts have been made to reproduce human stereo vision on rapidly changing computer displays, and toward this end numerous patents relating to 3D television and cinema have been filed in the USPTO. At least in the US, commercial activity involving those patents has been confined exclusively to the grantees and licensees of the patent holders, whose interests tend to last for twenty years from the time of filing. PTO headquarters in Alexandria The United States Patent and Trademark Office (PTO or USPTO) is an agency in the United States Department of Commerce that provides patent and trademark protection to inventors and businesses for their inventions and corporate and product identification. ...

Discounting 3D television and cinema (which generally require a plurality of digital projectors whose moving images must be synchronized by computer), several stereoscopic LCDs are going to be offered by Sharp, which has already started shipping a notebook with a built in stereoscopic LCD. Although older technology required the user to don goggles or visors for viewing computer-generated images, or CGI, newer technology tends to employ fresnel lenses or plates over the liquid crystal displays, freeing the user from the need to put on special glasses or goggles. The word sharp or acronym SHARP has several uses: Look up sharp in Wiktionary, the free dictionary. ... Fresnel Lens displayed in the Musée national de la marine in Paris, France A Fresnel lens is a type of lens invented by Augustin-Jean Fresnel (pronounced fre-NELL in scientific and lighting applications, although often incorrectly pronounced FREZ-nell). ...

References

• Scott B. Steinman, Barbara A. Steinman and Ralph Philip Garzia. (2000). Foundations of Binocular Vision: A Clinical perspective. McGraw-Hill Medical. ISBN 0-8385-2670-5

See also

• Orthoptics
• Vectograph
• Correspondence problem
• Epipolar geometry

Orthoptics, which literally means straightening of the eyes, dates back to the 1850s. ... The term vectograph refers to a kind of stereoscopic technology that uses polarized glasses to view a three-dimensional photographic image embedded in a plastic sheet. ... Given two or more images of the same 3D scene, taken from different points of view, the correspondence problem is to find a set of points in one image which can be indentified as the same points in another image. ... Epipolar geometry refers to the geometry of stereo vision. ...

External links

• Middlebury Stereo Vision Page
• What is Stereo Vision?