3d Art That Tricks the Eye Butterfly 3d Art That Tricks the Eye Tiger

Visual illusion of 3D scene accomplished by unfocusing eyes when viewing specific 2nd images

A random dot autostereogram encoding a 3D scene of a shark, which tin can be seen with proper viewing technique (). Click on thumbnail to meet full-size epitome.

A similar random dot autostereogram with the encoding of the 3D scene achieved by changes in move parallax instead of binocular parallax.

Cross-eyed vergence ().^[ane] Arrow indicates ac­com­mo­da­tion.

Wall-eyed ("parallel") convergence ().^[1]

The superlative and bottom images produce a paring or projection depending on whether viewed with cross- () or wall- () eyed vergence.

An autostereogram is a single-image stereogram (Sister), designed to create the visual illusion of a 3-dimensional (3D) scene from a ii-dimensional image. Most people with normal binocular vision are capable of seeing the depth in autostereograms, but to do so they must overcome the usually automated coordination between accommodation (focus of the eyes) and horizontal vergence (angle of the optics). The illusion is i of depth perception and involves stereopsis: depth perception arising from the different perspective each eye has of a three-dimensional scene, called binocular parallax.

About 5% of people take disordered binocular vision that prevents them from seeing the depth in autostereograms or in conventional stereograms viewed through a stereoscope. To illustrate the depth for such people, the second image has had the binocular parallax replaced by motion parallax: the amending in the position of points in the scene at different distances from a viewer's eyes equally the viewer's head moves. That is, this is a wiggle stereogram.

The simplest blazon of autostereogram consists of horizontally repeating patterns (ofttimes divide images) and is known as a wallpaper autostereogram. When viewed with proper vergence, the repeating patterns appear to float above or below the background. The well-known Magic Eye books feature another blazon of autostereogram called a random dot autostereogram, similar to the start instance, above. In this blazon of autostereogram, every pixel in the image is computed from a pattern strip and a depth map. A hidden 3D scene emerges when the paradigm is viewed with the correct vergence.

Autostereograms are similar to normal stereograms except they are viewed without a stereoscope. A stereoscope presents 2d images of the same object from slightly different angles to the left middle and the right eye, allowing usa to reconstruct the original object via binocular disparity. When viewed with the proper vergence, an autostereogram does the aforementioned, the binocular disparity existing in next parts of the repeating 2D patterns.

There are 2 ways an autostereogram can exist viewed: wall-eyed and cantankerous-eyed.^[a] Most autostereograms (including those in this article) are designed to be viewed in only one way, which is usually wall-eyed. Wall-eyed viewing requires that the two eyes prefer a relatively parallel angle, while cantankerous-eyed viewing requires a relatively convergent bending. An image designed for wall-eyed viewing if viewed correctly will appear to pop out of the groundwork, whereas if viewed cantankerous-eyed it will instead appear as a cut-out behind the background and may be difficult to bring entirely into focus.^[b]

History [edit]

In 1593, Giambattista della Porta viewed one page of a book with one eye and another page with the other center. He was able to read one of the pages, the other existence invisible, and switch "the visual virtue" to read the other folio, the first becoming invisible.^[2] This is an early example of dissociating vergence from accommodation—a necessary ability for seeing autostereograms. However, Porta saw competition between images viewed by the two eyes, binocular rivalry.

It was not until 1838 that the Charles Wheatstone published an example of cooperation between the images in the two optics: stereopsis (binocular depth perception). He explained that the depth arose from differences in the horizontal positions of the images in the ii eyes. He supported his caption past showing apartment, two-dimensional pictures with such horizontal differences, stereograms, separately to the left and correct eyes through a stereoscope he invented based on mirrors. From such pairs of flat images, people experienced the illusion of depth.^{[3] [4]}

In 1844, David Brewster discovered the "wallpaper effect".^[v] He noticed that when he stared at repeated patterns in wallpapers while varying his vergence, he could see them either behind the wall (with wall-eyed vergence) or in front of the wall (with cross-eyed vergence).^[6] This is the basis of wallpaper-style autostereograms.^[3]

In 1939 Boris Kompaneysky^[7] published the starting time, random-dot stereogram containing a hand-drawn paradigm of the face of Venus,^[8] intended to be viewed with a device.

In 1959, Bela Julesz,^{[9] [10]} vision scientist, psychologist, and MacArthur Fellow, invented random dot stereograms while working at Bell Laboratories on recognizing camouflaged objects from aerial pictures taken by spy planes. At the fourth dimension, many vision scientists assumed that stereopsis required prior analysis of visible contours of images in each eye, but Julesz showed information technology occurs with images with no such visible contours in each of the eyes. The contours of the depth object become visible only after stereopsis had candy the differences in the horizontal positions of dots in the two eyes' images.^{[11] [12]}

Japanese designer Masayuki Ito, following Julesz, created a unmarried epitome stereogram in 1970 and Swiss painter Alfons Schilling created a handmade single-epitome stereogram in 1974,^[8] after creating more than ane viewer and coming together with Julesz.^[13] Having experience with stereo imaging in holography, lenticular photography, and vectography, he developed a random-dot method based on closely spaced vertical lines in parallax.^[xiv]

In 1979, Christopher Tyler of Smith-Kettlewell Establish, a educatee of Julesz and a visual psychophysicist, combined the theories behind single-image wallpaper stereograms and random-dot stereograms (the work of Julesz and Schilling) to create the first black-and-white random-dot autostereogram with the assistance of computer programmer Maureen Clarke using Apple II and BASIC.^[15] Stork and Rocca published the first scholarly paper and provided software for generating random-dot stereograms.^[16] This type of autostereogram allows a person to run into 3D shapes from a unmarried 2D paradigm without the assistance of optical equipment.^{[17] [xviii]} In 1991 computer programmer Tom Baccei and artist Cheri Smith created the first colour random-dot autostereograms, afterwards marketed as Magic Eye.^[19]

A computer process that extracts back the hidden geometry out of an autostereogram image was described by Ron Kimmel.^[twenty] In addition to classical stereo information technology adds smoothness as an important assumption in the surface reconstruction.

In the belatedly 90's many children's magazines featured autostereograms. Even gaming magazines like Nintendo Ability had a section specifically made for these illusions.

How they work [edit]

Uncomplicated wallpaper [edit]

This is an instance of a wallpaper with repeated horizontal patterns. Each blueprint is repeated exactly every 140 pixels. The illusion of the pictures lying on a flat surface (a plane) farther back is created by the brain. Not-repeating patterns such as arrows and words, on the other hand, appear on the plane where this text lies.

Stereopsis, or stereo vision, is the visual blending of two similar but not identical images into one, with resulting visual perception of solidity and depth.^{[21] [22]} In the human encephalon, stereopsis results from complex mechanisms that form a 3-dimensional impression by matching each point (or set of points) in one eye'due south view with the equivalent point (or gear up of points) in the other center's view. Using binocular disparity, the brain derives the points' positions in the otherwise inscrutable z-axis (depth).

When the brain is presented with a repeating pattern like wallpaper, information technology has difficulty matching the two eyes' views accurately. By looking at a horizontally repeating pattern, only converging the ii optics at a point behind the pattern, it is possible to trick the encephalon into matching one element of the pattern, as seen by the left heart, with another (similar looking) element, abreast the showtime, as seen by the right eye. With the typical wall-eyed viewing, this gives the illusion of a plane bearing the aforementioned blueprint simply located backside the real wall. The distance at which this plane lies backside the wall depends only on the spacing between identical elements.^[23]

Autostereograms use this dependence of depth on spacing to create iii-dimensional images. If, over some expanse of the motion-picture show, the pattern is repeated at smaller distances, that expanse will appear closer than the background plane. If the distance of repeats is longer over some area, then that surface area will appear more than afar (like a hole in the aeroplane).

This autostereogram displays patterns on three different planes past repeating the patterns at different spacings. ()

People who take never been able to perceive 3D shapes hidden within an autostereogram discover it hard to understand remarks such every bit, "the 3D paradigm volition just pop out of the groundwork, after you stare at the picture long enough", or "the 3D objects will simply emerge from the background". It helps to illustrate how 3D images "emerge" from the groundwork from a second viewer'southward perspective. If the virtual 3D objects reconstructed by the autostereogram viewer's brain were real objects, a second viewer observing the scene from the side would meet these objects floating in the air above the background image.

The 3D effects in the example autostereogram are created past repeating the tiger rider icons every 140 pixels on the background plane, the shark passenger icons every 130 pixels on the second plane, and the tiger icons every 120 pixels on the highest airplane. The closer a set up of icons are packed horizontally, the higher they are lifted from the groundwork plane. This repeat distance is referred to as the depth or z-centrality value of a particular design in the autostereogram. The depth value is also known as Z-buffer value.

This picture show illustrates how 3D shapes from an autostereogram "emerge" from the background plane, when the autostereogram is viewed with proper eye divergence.

Depth or z-axis values are proportional to pixel shifts in the autostereogram.

The brain is capable of near instantly matching hundreds of patterns repeated at different intervals in lodge to recreate correct depth information for each pattern. An autostereogram may incorporate some fifty tigers of varying size, repeated at different intervals against a complex, repeated background. Nonetheless, despite the apparent chaotic system of patterns, the brain is able to identify every tiger icon at its proper depth.^{[ neutrality is disputed]}

The brain tin can place every tiger icon on its proper depth plane. ()

This image illustrates how an autostereogram is perceived past a viewer

Depth maps [edit]

Depth map instance autostereogram: Patterns in this autostereogram announced at different depth across each row.
Depth map greyscale example autostereogram: The black, gray and white colors in the background represent a depth map showing changes in depth beyond row.	Pattern image

Autostereograms where patterns in a particular row are repeated horizontally with the same spacing tin can be read either cross-eyed or wall-eyed. In such autostereograms, both types of reading will produce like depth interpretation, with the exception that the cross-eyed reading reverses the depth (images that once popped out are now pushed in).

However, icons in a row do not need to be arranged at identical intervals. An autostereogram with varying intervals between icons across a row presents these icons at different depth planes to the viewer. The depth for each icon is computed from the distance between information technology and its neighbor at the left. These types of autostereograms are designed to exist read in only 1 style, either cross-eyed or wall-eyed. All autostereograms in this article are encoded for wall-eyed viewing, unless specifically marked otherwise. An autostereogram encoded for wall-eyed viewing will produce inverse patterns when viewed cantankerous-eyed, and vice versa.^[b] Most Magic Eye pictures are besides designed for wall-eyed viewing.

The wall-eyed depth map example autostereogram to the right encodes three planes beyond the x-axis. The background aeroplane is on the left side of the picture. The highest plane is shown on the right side of the film. There is a narrow middle airplane in the centre of the x-axis. Starting with a groundwork airplane where icons are spaced at 140 pixels, i can raise a particular icon past shifting information technology a certain number of pixels to the left. For instance, the center plane is created by shifting an icon 10 pixels to the left, effectively creating a spacing consisting of 130 pixels. The encephalon does not rely on intelligible icons which stand for objects or concepts. In this autostereogram, patterns become smaller and smaller down the y-axis, until they await like random dots. The brain is still able to lucifer these random dot patterns.

The distance relationship between whatsoever pixel and its analogue in the equivalent pattern to the left can be expressed in a depth map. A depth map is only a grayscale epitome which represents the distance between a pixel and its left analogue using a grayscale value betwixt black and white.^[18] By convention, the closer the distance is, the brighter the colour becomes.

Using this convention, a grayscale depth map for the example autostereogram tin can be created with blackness, gray and white representing shifts of 0 pixels, 10 pixels and 20 pixels, respectively as shown in the greyscale example autostereogram. A depth map is the fundamental to creation of random-dot autostereograms.

Random-dot [edit]

A computer program can take a depth map and an accompanying pattern image to produce an autostereogram. The program tiles the design image horizontally to cover an surface area whose size is identical to the depth map. Conceptually, at every pixel in the output paradigm, the program looks upward the grayscale value of the equivalent pixel in the depth map image, and uses this value to make up one's mind the amount of horizontal shift required for the pixel.

One way to accomplish this is to brand the plan scan every line in the output image pixel-by-pixel from left to right. It seeds the starting time series of pixels in a row from the pattern image. So it consults the depth map to retrieve appropriate shift values for subsequent pixels. For every pixel, it subtracts the shift from the width of the pattern epitome to go far at a repeat interval. It uses this echo interval to look upwards the color of the analogue pixel to the left and uses its color as the new pixel's own color.^[23]

Three raised rectangles announced on different depth planes in this autostereogram. ()

Every pixel in an autostereogram obeys the distance interval specified past the depth map.

Unlike the simple depth planes created past elementary wallpaper autostereograms, subtle changes in spacing specified by the depth map can create the illusion of shine gradients in distance. This is possible because the grayscale depth map allows individual pixels to be placed on one of ii ⁿ depth planes, where due north is the number of $.25 used by each pixel in the depth map. In practice, the total number of depth planes is determined by the number of pixels used for the width of the pattern image. Each grayscale value must be translated into pixel infinite in order to shift pixels in the final autostereogram. As a result, the number of depth planes must be smaller than the pattern width.

This random dot autostereogram features a raised shark with fine gradient on a flat background. ()

The revelation of the shark.

The fine-tuned gradient requires a pattern image more complex than standard repeating-pattern wallpaper, so typically a blueprint consisting of repeated random dots is used. When the autostereogram is viewed with proper viewing technique, a hidden 3D scene emerges. Autostereograms of this form are known as Random Dot Autostereograms.

Smooth gradients can also exist achieved with an intelligible blueprint, bold that the design is complex enough and does non have large, horizontal, monotonic patches. A big area painted with monotonic colour without change in hue and effulgence does not lend itself to pixel shifting, as the result of the horizontal shift is identical to the original patch. The post-obit depth map of a shark with smooth gradient produces a perfectly readable autostereogram, even though the 2D image contains small-scale monotonic areas; the brain is able to recognize these small gaps and fill in the blanks (illusory contours). While intelligible, repeated patterns are used instead of random dots, this type of autostereogram is still known by many as a Random Dot Autostereogram, because information technology is created using the same process.

The shark figure in this depth map is fatigued with a polish gradient.

The 3D shark in this random-dot autostereogram has a smooth, circular shape due to the use of depth map with shine gradient. ()

Animated [edit]

When a serial of autostereograms are shown one after some other, in the same way moving pictures are shown, the brain perceives an blithe autostereogram. If all autostereograms in the animation are produced using the same background design, it is often possible to see faint outlines of parts of the moving 3D object in the 2nd autostereogram image without wall-eyed viewing; the constantly shifting pixels of the moving object can be clearly distinguished from the static background plane. To eliminate this side upshot, animated autostereograms often use shifting groundwork in club to disguise the moving parts.

When a regular repeating pattern is viewed on a CRT monitor as if it were a wallpaper autostereogram, it is usually possible to see depth ripples. This can also be seen in the background to a static, random-dot autostereogram. These are acquired by the sideways shifts in the epitome due to modest changes in the deflection sensitivity (linearity) of the line browse, which then become interpreted as depth. This event is particularly apparent at the left hand edge of the screen where the browse speed is still settling after the flyback phase. On a TFT LCD, which functions differently, this does not occur and the issue is not nowadays. Higher quality CRT displays also accept ameliorate linearity and exhibit less or none of this effect.

Mechanisms for viewing [edit]

Much advice exists about seeing the intended three-dimensional image in an autostereogram. While some people may quickly see the 3D image in an autostereogram with trivial effort, others must learn to railroad train their eyes to decouple middle convergence from lens focusing.

Not every person can see the 3D illusion in autostereograms. Because autostereograms are synthetic based on stereo vision, persons with a variety of visual impairments, even those affecting only i middle, are unable to see the three-dimensional images.

People with amblyopia (also known as lazy eye) are unable to see the three-dimensional images. Children with poor or dysfunctional eyesight during a critical menstruum in childhood may grow up stereoblind, every bit their brains are not stimulated by stereo images during the critical period. If such a vision problem is non corrected in early on childhood, the damage becomes permanent and the adult will never exist able to come across autostereograms.^{[3] [c]} It is estimated that some 1 percent to 5 percent of the population is afflicted by amblyopia.^[25]

3D perception [edit]

Depth perception results from many monocular and binocular visual clues. For objects relatively close to the eyes, binocular vision plays an important role in depth perception. Binocular vision allows the encephalon to create a single Cyclopean image and to adhere a depth level to each point in it.^[eleven]

The ii optics converge on the object of attention.

The encephalon creates a Cyclopean epitome from the two images received by the 2 eyes.

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

The encephalon uses coordinate shift (also known as parallax) of matched objects to identify depth of these objects.^[23] The depth level of each point in the combined paradigm can be represented by a grayscale pixel on a 2d epitome, for the do good of the reader. The closer a indicate appears to the brain, the brighter it is painted. Thus, the fashion the brain perceives depth using binocular vision tin exist captured by a depth map (Cyclopean image) painted based on coordinate shift.

The middle adjusts its internal lens to become a clear, focused image

The two optics converge to point to the same object

The eye operates like a photographic photographic camera. It has an adjustable iris which tin open (or close) to allow more (or less) light to enter the middle. Every bit with whatsoever photographic camera except pinhole cameras, it needs to focus low-cal rays entering through the iris (discontinuity in a camera) and then that they focus on a single point on the retina in order to produce a sharp image. The eye achieves this goal by adjusting a lens behind the cornea to refract light appropriately.

When a person stares at an object, the two eyeballs rotate sideways to point to the object, so that the object appears at the middle of the image formed on each eye'due south retina. In order to wait at a nearby object, the 2 eyeballs rotate towards each other so that their eyesight can converge on the object. This is referred to as cross-eyed viewing. To meet a faraway object, the two eyeballs diverge to become almost parallel to each other. This is known as wall-eyed viewing, where the convergence bending is much smaller than that in cross-eyed viewing.^[a]

Stereo-vision based on parallax allows the encephalon to calculate depths of objects relative to the point of convergence. It is the convergence bending that gives the brain the absolute reference depth value for the point of convergence from which absolute depths of all other objects can be inferred.

Faux 3D perception [edit]

Decoupling focus from convergence tricks the encephalon into seeing 3D images in a 2D autostereogram

The eyes normally focus and converge at the same distance in a process known equally accommodative convergence. That is, when looking at a faraway object, the brain automatically flattens the lenses and rotates the 2 eyeballs for wall-eyed viewing. It is possible to train the brain to decouple these ii operations. This decoupling has no useful purpose in everyday life, because it prevents the encephalon from interpreting objects in a coherent manner. To run across a homo-fabricated moving-picture show such equally an autostereogram where patterns are repeated horizontally, nevertheless, decoupling of focusing from convergence is crucial.^[3]

By focusing the lenses on a nearby autostereogram where patterns are repeated and by converging the eyeballs at a distant bespeak behind the autostereogram image, one can trick the brain into seeing 3D images. If the patterns received by the two optics are similar enough, the brain volition consider these two patterns a match and treat them as coming from the same imaginary object. This type of visualization is known as wall-eyed viewing, because the eyeballs prefer a wall-eyed convergence on a distant plane, fifty-fifty though the autostereogram image is really closer to the eyes.^[23] Because the ii eyeballs converge on a plane farther away, the perceived location of the imaginary object is behind the autostereogram. The imaginary object likewise appears bigger than the patterns on the autostereogram because of foreshortening.

The following autostereogram shows 3 rows of repeated patterns. Each design is repeated at a different interval to place it on a different depth plane. The two non-repeating lines can exist used to verify correct wall-eyed viewing. When the autostereogram is correctly interpreted by the encephalon using wall-eyed viewing, and one stares at the dolphin in the center of the visual field, the brain should run across ii sets of flickering lines, equally a upshot of binocular rivalry.^[11]

The ii blackness lines in this Autostereogram help viewers establish proper wall-eyed viewing, see right.

When the brain manages to establish proper wall-eyed viewing, information technology will run into two sets of lines.

Top-row cubes appear farther away and bigger. ()

While there are six dolphin patterns in the autostereogram, the encephalon should see seven "apparent" dolphins on the plane of the autostereogram. This is a side effect of the pairing of similar patterns by the brain. There are five pairs of dolphin patterns in this epitome. This allows the brain to create five apparent dolphins. The leftmost pattern and the rightmost pattern by themselves have no partner, merely the brain tries to assimilate these 2 patterns onto the established depth plane of adjacent dolphins despite binocular rivalry. As a result, there are vii credible dolphins, with the leftmost and the rightmost ones appearing with a slight flicker, not dissimilar to the two sets of flickering lines observed when i stares at the 4th apparent dolphin.

Because of foreshortening, the difference in convergence needed to see repeated patterns on unlike planes causes the brain to attribute unlike sizes to patterns with identical 2nd sizes. In the autostereogram of three rows of cubes, while all cubes have the same physical 2D dimensions, the ones on the top row announced bigger, because they are perceived as farther away than the cubes on the second and 3rd rows.

Viewing techniques [edit]

Collywobbles, cross-eyed autostereogram ()

If one has two optics, fairly good for you eyesight, and no neurological conditions which foreclose the perception of depth, and so i is capable of learning to see the images within autostereograms.^{[ citation needed ]} "Similar learning to ride a bicycle or to swim, some option information technology up immediately, while others have a harder time."^[26]

Every bit with a photographic camera, it is easier to make the center focus on an object when there is intense ambience light. With intense lighting, the middle can tuck the pupil, even so allow plenty light to achieve the retina. The more than the center resembles a pinhole camera, the less it depends on focusing through the lens.^[d] In other words, the degree of decoupling between focusing and convergence needed to visualize an autostereogram is reduced. This places less strain on the encephalon. Therefore, it may be easier for first-time autostereogram viewers to "meet" their first 3D images if they endeavor this feat with bright lighting.

Vergence command is of import in being able to see 3D images. Thus information technology may aid to concentrate on converging/diverging the two eyes to shift images that attain the two eyes, instead of trying to encounter a clear, focused image. Although the lens adjusts reflexively in social club to produce clear, focused images, voluntary control over this process is possible.^[27] The viewer alternates instead between converging and diverging the two eyes, in the process seeing "double images" typically seen when one is drunk or otherwise intoxicated. Somewhen the brain will successfully match a pair of patterns reported by the two eyes and lock onto this particular caste of convergence. The brain will also adjust eye lenses to get a articulate paradigm of the matched pair. Once this is done, the images around the matched patterns speedily become clear as the encephalon matches additional patterns using roughly the same degree of convergence.

A type of wallpaper autostereogram featuring 3D objects instead of flat patterns ()

The lesser part of this autostereogram is complimentary of 3D images. It is easier to trick the brain into matching pairs of patterns in this area. ()

When one moves 1'south attending from one depth plane to some other (for instance, from the top row of the chessboard to the lesser row), the two optics need to adjust their convergence to match the new repeating interval of patterns. If the level of change in convergence is too high during this shift, sometimes the brain tin can lose the hard-earned decoupling betwixt focusing and convergence. For a start-time viewer, therefore, it may be easier to run across the autostereogram, if the 2 eyes rehearse the convergence exercise on an autostereogram where the depth of patterns across a item row remains constant.

In a random dot autostereogram, the 3D image is usually shown in the middle of the autostereogram against a background depth plane (see the shark autostereogram). Information technology may assistance to establish proper convergence first by staring at either the top or the lesser of the autostereogram, where patterns are commonly repeated at a constant interval. Once the brain locks onto the background depth airplane, it has a reference convergence degree from which it can then friction match patterns at dissimilar depth levels in the center of the image.

The majority of autostereograms, including those in this commodity, are designed for divergent (wall-eyed) viewing. One mode to help the brain concentrate on divergence instead of focusing is to hold the flick in front of the face up, with the nose touching the film. With the picture so close to their eyes, about people cannot focus on the picture. The brain may give up trying to move eye muscles in order to get a clear movie. If one slowly pulls dorsum the picture away from the face up, while refraining from focusing or rotating eyes, at some point the encephalon will lock onto a pair of patterns when the altitude betwixt them matches the current convergence degree of the two eyeballs.^[17]

Another way is to stare at an object behind the picture show in an attempt to establish proper departure, while keeping part of the eyesight fixed on the picture to convince the brain to focus on the film. A modified method has the viewer focus on their reflection on a reflective surface of the picture, which the encephalon perceives as being located twice every bit far away as the picture itself. This may assistance persuade the brain to adopt the required deviation while focusing on the nearby moving-picture show.^[28]

For crossed-eyed autostereograms, a dissimilar approach needs to exist taken. The viewer may concur one finger betwixt their eyes and movement it slowly towards the picture show, maintaining focus on the finger at all times, until they are correctly focused on the spot that will allow them to view the illusion.

Stereoblindness, however, is non known to permit the usages of whatsoever of these techniques, especially for persons in whom information technology may exist, or is, permanent.

Terminology [edit]

• Stereogram and autostereogram

Stereogram was originally used to depict as a pair of 2nd images used in stereoscope to present a 3D epitome to viewers. The "automobile" in autostereogram describes an image that does not require a stereoscope. The term stereogram is now frequently used interchangeably with autostereogram.^[29] Dr. Christopher Tyler, inventor of the autostereogram, consistently refers to single prototype stereograms equally autostereograms to distinguish them from other forms of stereograms.^{[eighteen] [ need quotation to verify ]}

• Random dot stereogram (RDS)

Random dot stereogram, describes a pair of second images containing random dots which, when viewed with a stereoscope, produced a 3D prototype. The term is at present frequently used interchangeably with random dot autostereogram.^{[17] [23]}

• Single image stereogram (Sis)

Single image stereogram (Sister). SIS differs from earlier stereograms in its apply of a single 2D image instead of a stereo pair and is viewed without a device. Thus, the term is often used as a synonym of autostereogram. When the unmarried 2d epitome is viewed with proper middle convergence, information technology causes the brain to fuse different patterns perceived by the two eyes into a virtual 3D epitome without, hidden within the 2d paradigm, the assistance of whatever optical equipment. Sister images are created using a repeating pattern.^{[18] [30]} Programs for their creation include Mathematica.^{[31] [32]}

• Random dot autostereogram/hidden paradigm stereogram

Is besides known as unmarried image random dot stereogram (SIRDS). This term also refers to autostereograms where the subconscious 3D image is created using a random design of dots within i image,^[30] shaped past a depth map inside a defended stereogram rendering programme.^[33]

• Wallpaper autostereogram/object array stereogram/texture kickoff stereogram

Wallpaper autostereogram is a single second image where recognizable patterns are repeated at various intervals to raise or lower each pattern's perceived 3D location in relation to the brandish surface. Despite the repetition, these are a type of unmarried image autostereogram.

• Single image random text stereogram (SIRTS)

A unmarried paradigm random text ASCII stereogram is an alternative to SIRDS using random ASCII text instead of dots to produce a 3D grade of ASCII art.

• Map textured stereogram

In a map textured stereogram, "a fitted texture is mapped onto the depth image and repeated a number of times" resulting in a pattern where the resulting 3D image is oft partially or fully visible before viewing.^[33]

See also [edit]

• Diplopia
• Lenticular press

Notes [edit]

1. ^ ^{a b} The terms "cross-eyed" and "wall-eyed" are borrowed from synonyms for various forms of strabismus, a condition where eyes do not point in the same direction when looking at an object. Wall-eyed viewing is informally known as parallel-viewing.
2. ^ ^{a b} If a two-image stereogram, wallpaper, or random-dot autostereogram designed for wall-eyed viewing is viewed cantankerous-eyed, or vice versa, all details on the z-centrality will be reversed – objects that were meant to be seen to rise above the background will appear to sink into information technology. Still, there may be some incoherence due to overlapping (an object originally intended to projection in forepart of another object will now project backside information technology). For example, the black lines in File:Stereogram Tut Simple.png.
3. ^ It is generally thought that amblyopia is a permanent condition, but NPR reports a example where a patient with amblyopia regains stereo vision (Susan R. Barry).^[24]
4. ^ Meet aperture on similarity between aperture and educatee. See depth of field for relationship between aperture and lens.

References [edit]

1. ^ ^{a b c} Stephen M. Kosslyn, Daniel N. Osherson (1995). An Invitation to Cerebral Science, 2d Edition - Vol. 2: Visual Noesis, p. 65 fig. one.49. ISBN 978-0-262-15042-2.
2. ^ Wade, Nicholas (1996). "Descriptions of visual phenomena from Aristotle to Wheatstone". Perception. 25: 1137-1175. doi:x.1068/p251137.
3. ^ ^{a b c d} Pinker, S. (1997). "The Mind's Middle", How the Mind Works, pp. 211–233. ISBN 0-393-31848-6.
4. ^ Wheatstone, Charles (1838). "Contributions to the Physiology of Vision, ane. On Some Remarkable, and Hitherto Unobserved, Phenomena of Binocular Vision", Philosophical Transactions. London: Regal Order of London. (Stereoscopy.com).
5. ^ Brewster, David (1844). "On the noesis of distance given by binocular vision" (PDF). Transactions of the Regal Gild of Edinburgh. xv: 663–674, Plate 17.
6. ^ Tyler, Christopher (2014). "Autostereogram". Scholarpedia. doi:x.4249/scholarpedia.9229.
7. ^ Kompaneysky, Boris N. (1939). "Depth sensations: Analysis of the theory of simulation past non exactly corresponding points", Bulletin of Ophthalmology (USSR) 14, pp. 90–105. (in Russian)
8. ^ ^{a b} Weibel, Peter (2005). Beyond Art: A Third Culture: A Comparative Written report in Cultures, Art and Scientific discipline in 20th Century Austria and Hungary, p. 29. ISBN 978-3-211-24562-0.
9. ^ Julesz, Bela (1960). "Binocular depth perception of computer-generated patterns", Bell Technical Periodical, p. 39.
10. ^ Julesz, Bela (1964). "Binocular depth perception without familiarity cues", Science, p. 145.
11. ^ ^{a b c} Julesz, B. (1971). Foundations of Cyclopean Perception,^{[ page needed ]}. Chicago: The University of Chicago Printing. ISBN 0-226-41527-nine.
12. ^ Shimoj, S. (1994). Interview with Bela Julesz. In Horibuchi, S. (Ed.), Super Stereogram, pp. 85–93. San Francisco: Cadency Books. ISBN 1-56931-025-4.
13. ^ Weibel (2005), p. 125.
14. ^ Sakana, Itsuo (1994). Stereogram, pp. 75–76. Ed. Seiji Horibuchi and Yuki Inonue. San Francisco: Cadence Books. ISBN 978-0-929279-85-v
15. ^ Tyler, Christopher Westward. (1983). "Sensory processing of binocular disparity", Vergence Eye Movements, Basic and Clinical Aspects,^{[ page needed ]}. ed. L.One thousand. Schor and G.J. Ciuffreda. London. 0409950327.
16. ^ Stork, David G. and Rocca, Chris (1989). "Software for creating auto-random-dot stereograms", Beliefs Research methods, Instruments and Computers, 21(5):525-534.
17. ^ ^{a b c} Magic Eye Inc. (2004). Magic Heart: Beyond 3D,^{[ page needed ]}. Kansas Metropolis: Andrews McMeel Publishing. ISBN 0-7407-4527-one.
18. ^ ^{a b c d} Tyler, C.W. (1994). "The Nascence of Computer Stereograms for Unaided Stereovision". In Horibuchi, S. (Ed.), Stereogram (pp. 83–89). San Francisco: Cadency Books. ISBN 0-929279-85-9.
19. ^ Ione, Amy (2005). Innovation and Visualization: Trajectories, Strategies, and Myths. p. 211. ISBN9042016752 . Retrieved 2013-07-02 .
20. ^ R. Kimmel. (2002) 3D Shape Reconstruction from Autostereograms and Stereo. Journal of Visual Communication and Image Representation, 13:324–333.
21. ^ Cassin, B. and Solomon, S. (1990). Lexicon of Centre Terminology,^{[ folio needed ]}. Gainesville, Florida: Triad Publishing Company. ISBN 978-0-937404-33-ane
22. ^ Tyler, Christopher W., Lauren Barghout, and Leonid L. Kontsevich. "Computational reconstruction of the mechanisms of human stereopsis." Computational Vision Based on Neurobiology. International Society for Eyes and Photonics, 1994.
23. ^ ^{a b c d east} Andrew A. Kinsman (1992). Random Dot Stereograms,^{[ page needed ]}. Rochester: Kinsman Physics. ISBN 0-9630142-one-viii.
24. ^ Krulwich, Robert (2006). "Going Binocular: Susan'southward Beginning Snowfall", NPR.org.
25. ^ Webber, Ann; Joanne Wood (Nov 2005). "Amblyopia - prevalence, natural history, functional effects and treatment". Clinical and Experimental Optometry. 88 (6): 365–375. doi:x.1111/j.1444-0938.2005.tb05102.10. PMID 16329744. S2CID 39141527. Archived from the original on 2006-08-21. Retrieved 2006-07-17 .
26. ^ Kosslyn and Osherson (1995), p. 64.
27. ^ McLin LN Jr, Schor CM (1988 Nov). "Voluntary endeavor as a stimulus to adaptation and vergence.", Invest Ophthalmol Vis Sci., Vol. 29, No. 11, pp. 1739–46. PMID 3182206.
28. ^ Magic Eye Inc. (2004). Magic Eye: 3D Hidden Treasures,^{[ folio needed ]}. Kansas Urban center: Andrews McMeel Publishing. ISBN 0-7407-4791-6.
29. ^ Horibuchi, S. (1994). Stereogram, pp. 8–10, 22, 32, 36. San Francisco: Cadence Books. ISBN 0-929279-85-ix. The term stereogram is used as a synonym of stereo pair, autostereogram, and random dot autostereogram throughout the book.
30. ^ ^{a b} Open University Course Squad (2008) The Science of the Senses, p. 183. Open up University. ISBN 0-7492-1450-3.
31. ^ Donald Row, Talmage James Reid (2011). Geometry, Perspective Cartoon, and Mechanisms, p. 142. ISBN 978-981-4343-82-4.
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33. ^ ^{a b} Gene Levine, Gary W. Priester (2008). Hidden Treasures: 3-D Stereograms,^{[ page needed ]}. ISBN 978-i-4027-5145-five.

Bibliography [edit]

• Northward. E. Thing Enterprises (1993). Magic Middle: A New Style of Looking at the World. Kansas Urban center: Andrews and McMeel. ISBN 0-8362-7006-1
• Tyler, C.W. and Clarke, One thousand.B. (1990) "The Autostereogram". Stereoscopic Displays and Applications, Proc. SPIE Vol. 1258:182–196.
• Marr, D. and Poggio, T. (1976). "Cooperative computation of stereo disparity". Science, 194:283–287; October 15.
• Julesz, B. (1964). "Binocular depth perception without familiarity cues". Science, 145:356–363.
• Julesz, B. (1963). "Stereopsis and binocular 3d Stereogram rivalry of contours". Journal of the Optical Society of America, 53:994–999.
• Julesz, B. and J.E. Miller. (1962). "Automated stereoscopic presentation of functions of two variables". Bell Organisation Technical Journal, 41:663–676; March.
• 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-v
• Ron Kimmel. (2002) 3D Shape Reconstruction from Autostereograms and Stereo. Journal of Visual Advice and Prototype Representation, 13:324–333.

External links [edit]

• Media related to Autostereograms at Wikimedia Commons
• Scholarpedia article on autostereograms Peer-reviewed article on autostereograms past Christopher Tyler
• Stereograma - A Free Open-Source Cross-Platform Stereogram Generator
• Autostereograms - 3D Magic eye, SIRDS - Gallery Images
• Online ASCII stereogram generator
• Animated autostereogram of ii tori at the Wayback Machine (archived March 26, 2009)

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