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Random-dot Stereogram
A random-dot stereogram (RDS) is stereo pair of images of random dots that, when viewed with the aid of a stereoscope, or with the eyes focused on a point in front of or behind the images, produces a sensation of depth due to stereopsis, with objects appearing to be in front of or behind the display level. The random-dot stereogram technique, known since 1919, was elaborated on by Béla Julesz, described in his 1971 book, '' Foundations of Cyclopean Perception''. Later concepts, involving single images, not necessarily consisting of random dots, and more well known to the general public, are autostereograms. History In 1840, Sir Charles Wheatstone developed the stereoscope. Using it, two photographs, taken a small horizontal distance apart, could be viewed one to each eye so that the objects in the photograph appeared to be three-dimensional in a three-dimensional scene. Around 1956, Béla Julesz initiated a project at Bell Labs aimed at identifying patterns within the output o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoscopy
Stereoscopy, also called stereoscopics or stereo imaging, is a technique for creating or enhancing the depth perception, illusion of depth in an image by means of stereopsis for binocular vision. The word ''stereoscopy'' derives . Any stereoscopic image is called a stereogram. Originally, stereogram referred to a pair of stereo images which could be viewed using a stereoscope. Most stereoscopic methods present a pair of two-dimensional images to the viewer. The left image is presented to the left eye and the right image is presented to the right eye. When viewed, the human brain perceives the images as a single 3D view, giving the viewer the perception of Three-dimensional space, 3D depth. However, the 3D effect lacks proper focal depth, which gives rise to the Vergence-accommodation conflict. Stereoscopy is distinguished from other types of 3d display#3D displays, 3D displays that display an image in Three-dimensional space, three full dimensions, allowing the observer to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suppression (eye)
Suppression of an eye is a subconscious adaptation by a person's brain to eliminate the symptoms of disorders of binocular vision such as strabismus, convergence insufficiency and aniseikonia. The brain can eliminate double vision by ignoring all or part of the image of one of the eyes. The area of a person's visual field that is suppressed is called the suppression scotoma (with a scotoma meaning, more generally, an area of partial alteration in the visual field). Suppression can lead to amblyopia. Effect Nobel-prize winner David H. Hubel described suppression in simple terms as follows: :"Suppression is familiar to anyone who has trained himself to look through a monocular microscope, sight a gun, or do any other strictly one-eye task, with the other eye open. The scene simply disappears for the suppressed eye."David H. Hubel: ''Eye, Brain, and Vision'', Chapter 9 "Deprivation and development"section "Strabismus" Published online by Harvard Medical School (downloaded 30 Septembe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binocular Disparity
Binocular disparity refers to the difference in image location of similar features seen by the left and right eyes resulting from the eyes' horizontal separation (parallax). In visual perception, binocular disparity refers to edges and small blobs with Double-nail_illusion#equal_contrast_sign, equal contrast sign in the retinal images. The mind extracts binocular disparity for these edges and blobs and then Double-nail_illusion#fills_in_surfaces, fills in the depth and forms of surfaces, resulting in Binocular_vision#Stereopsis, stereopsis. Related terms There exists also vertical disparities which result from height level differences and which can also invoke a depth sensation.Matthews N;Meng X.; Xu P; Qian Q.(2003) “A physiological theory of depth perception from vertical disparity”, Vision Research. Volume 43, Issue 1, January 2003, Pages 85-99. In stereoscopy and computer vision, binocular disparity refers to the difference in coordinates of similar features within t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autostereogram
An autostereogram is a two-dimensional (2D) image that can create the optical illusion of a three-dimensional (3D) scene. Autostereograms use only one image to accomplish the effect while normal stereograms require two. The 3D scene in an autostereogram is often unrecognizable until it is viewed properly, unlike typical stereograms. Viewing any kind of stereogram properly may cause the viewer to experience vergence-accommodation conflict. The optical illusion of an autostereogram 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. Individuals with disordered binocular vision and who cannot perceive depth may require a wiggle stereogram to achieve a similar effect. The simplest type of autostereogram consists of a horizontally repeating pattern, with small changes throughout, that looks like wallpaper. When viewed with proper vergence, the repeating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Dot Stereogram Pair
In common usage, randomness is the apparent or actual lack of definite pattern or predictability in information. A random sequence of events, symbols or steps often has no order and does not follow an intelligible pattern or combination. Individual random events are, by definition, unpredictable, but if there is a known probability distribution, the frequency of different outcomes over repeated events (or "trials") is predictable.Strictly speaking, the frequency of an outcome will converge almost surely to a predictable value as the number of trials becomes arbitrarily large. Non-convergence or convergence to a different value is possible, but has probability zero. Consistent non-convergence is thus evidence of the lack of a fixed probability distribution, as in many evolutionary processes. For example, when throwing two dice, the outcome of any particular roll is unpredictable, but a sum of 7 will tend to occur twice as often as 4. In this view, randomness is not haphazardne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strabismus
Strabismus is an eye disorder in which the eyes do not properly align with each other when looking at an object. The eye that is pointed at an object can alternate. The condition may be present occasionally or constantly. If present during a large part of childhood, it may result in amblyopia, or lazy eyes, and loss of depth perception. If onset is during adulthood, it is more likely to result in diplopia, double vision. Strabismus can occur out of muscle dysfunction (e.g., myasthenia gravis), farsightedness, problems in the brain, trauma, or infections. Risk factors include premature birth, cerebral palsy, and a family history of the condition. Types include esotropia, where the eyes are crossed ("cross eyed"); exotropia, where the eyes diverge ("lazy eyed" or "wall eyed"); and hypertropia or hypotropia, where they are vertically misaligned. They can also be classified by whether the problem is present in all directions a person looks (comitant) or varies by direction (inco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoscopic Motion
Stereoscopic motion, as introduced by Béla Julesz in his book '' Foundations of Cyclopean Perception'' of 1971, is a translational motion of figure boundaries defined by changes in binocular disparity over time in a real-life 3D scene, a 3D film or other stereoscopic scene. This translational motion gives rise to a mental representation of three dimensional motion created in the brain on the basis of the binocular motion stimuli. Whereas the motion stimuli as presented to the eyes have a different direction for each eye, the stereoscopic motion is perceived as yet another direction on the basis of the views of both eyes taken together. Stereoscopic motion, as it is perceived by the brain, is also referred to as ''cyclopean motion'', and the processing of visual input that takes place in the visual system relating to stereoscopic motion is called ''stereoscopic motion processing''. Provided the binocular motion stimuli correspond to a physical object moving in 3D space, the ster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichoptic Presentation
Dichoptic () is viewing a separate and independent field by each eye. In dichoptic presentation, stimulus A is presented to the left eye and a different stimulus B is presented to the right eye. Dichoptic moving images and games Dichoptic perceptual training has been tested in order to stimulate the simultaneous use of both eyes. In recent years, efforts have been made to develop methods of perceptual learning in vision therapy for treating interocular suppression and improving binocular vision in patients with anisometropic or strabismic amblyopia. In these methods, data has been presented within a virtual reality environment, and has also been presented using a computer screen or handheld device together with matched active or passive filter glasses for the user, which present a different image to each eye. In order to balance the input of visual information from each eye to the brain, the data is presented in such a manner that the user needs to use both eyes to see the comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoscopic Displays And Applications
Stereoscopic Displays and Applications (SD&A) is an academic technical conference in the field of stereoscopic 3D imaging. The conference started in 1990 and is held annually. The conference is held as part of the annual Electronic Imaging: Science and Technology Symposium organised by the Society for Imaging Science and Technology (IS&T). Scope SD&A is an academic technical conference dedicated to stereoscopic imaging topics, specializing in all forms of stereoscopic imaging, including stereoscopic 3D display hardware, stereoscopic 3D image capture, stereoscopic 3D image storage and processing, and also applications of these technologies. As well as including coverage of two-view 3D displays, the conference includes significant coverage of multi-view autostereoscopic displays and volumetric 3D displays - any system that stimulates stereoscopic vision in an observer. Overview The backbone of the annual SD&A conference is the technical presentations, which are all accompanie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
