Proposed Explanation of the Phi Phenomenon from a Basic Neural Viewpoint
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Optical Illusion - Wikipedia, the Free Encyclopedia
Optical illusion - Wikipedia, the free encyclopedia Try Beta Log in / create account article discussion edit this page history [Hide] Wikipedia is there when you need it — now it needs you. $0.6M USD $7.5M USD Donate Now navigation Optical illusion Main page From Wikipedia, the free encyclopedia Contents Featured content This article is about visual perception. See Optical Illusion (album) for Current events information about the Time Requiem album. Random article An optical illusion (also called a visual illusion) is characterized by search visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a percept that does not tally with a physical measurement of the stimulus source. There are three main types: literal optical illusions that create images that are interaction different from the objects that make them, physiological ones that are the An optical illusion. The square A About Wikipedia effects on the eyes and brain of excessive stimulation of a specific type is exactly the same shade of grey Community portal (brightness, tilt, color, movement), and cognitive illusions where the eye as square B. See Same color Recent changes and brain make unconscious inferences. illusion Contact Wikipedia Donate to Wikipedia Contents [hide] Help 1 Physiological illusions toolbox 2 Cognitive illusions 3 Explanation of cognitive illusions What links here 3.1 Perceptual organization Related changes 3.2 Depth and motion perception Upload file Special pages 3.3 Color and brightness -
Chapter 6 Visual Perception
Chapter 6 Visual Perception Steven M. LaValle University of Oulu Copyright Steven M. LaValle 2019 Available for downloading at http://vr.cs.uiuc.edu/ 154 S. M. LaValle: Virtual Reality Chapter 6 Visual Perception This chapter continues where Chapter 5 left off by transitioning from the phys- iology of human vision to perception. If we were computers, then this transition might seem like going from low-level hardware to higher-level software and algo- rithms. How do our brains interpret the world around us so effectively in spite of our limited biological hardware? To understand how we may be fooled by visual stimuli presented by a display, you must first understand how our we perceive or interpret the real world under normal circumstances. It is not always clear what we will perceive. We have already seen several optical illusions. VR itself can be Figure 6.1: This painting uses a monocular depth cue called a texture gradient to considered as a grand optical illusion. Under what conditions will it succeed or enhance depth perception: The bricks become smaller and thinner as the depth fail? increases. Other cues arise from perspective projection, including height in the vi- Section 6.1 covers perception of the distance of objects from our eyes, which sual field and retinal image size. (“Paris Street, Rainy Day,” Gustave Caillebotte, is also related to the perception of object scale. Section 6.2 explains how we 1877. Art Institute of Chicago.) perceive motion. An important part of this is the illusion of motion that we perceive from videos, which are merely a sequence of pictures. -
Sensation and Perception
Sensation vs. Perception • Sensation vs. Perception • Physical stimulus → Physiological response → Sensation and Perception Sensory experience & interpretation • Example vision research questions: Chapter 5 – How does the eye take light and transform it into a message the brain can understand? Vision: p. 135 - 156 – How do we see a stable world even though our eyes are constantly blinking and shifting? – How do perceptual illusions trick the mind? Visual system Physical properties of light • Wavelength – Hue • Amplitude – Intensity/brightness • Mix of wavelengths – Saturation The Eye Blindspot demonstration Transduction Process to translate light into an electro- chemical message for the brain Accommodation Lens changes shape to focus light on retina Demo in text p.141 http://faculty.washington.edu/chudler/chvision.html 1 Vision problems Photoreceptors Accomodation = shape of lens changes to focus Rods Flexibility lost with increased age = Presbyopia – Concentrated in periphery of retina – Low light ok – No detail, no color Cones – Concentrated in fovea – Needs full light – High visual acuity – Color receptors http://faculty.washington.edu/chudler/sight.html The three main layers of the retina Dark adaptation Color theories Opponent-process theory E. Herig Photopigments have to be regenerated by cells Trichromatic theory H. von Helmholz Negative afterimage Lilac Chaser • http://michaelbach.de/ot/col_lilacChaser/index.html http://faculty.washington.edu/chudler/after.html Text demo p155 http://michaelbach.de/ot/col_rapidAfterimage/index.html -
Indirect Perception: Chap14
This excerpt from Indirect Perception. Irvin Rock. © 1997 The MIT Press. is provided in screen-viewable form for personal use only by members of MIT CogNet. Unauthorized use or dissemination of this information is expressly forbidden. If you have any questions about this material, please contact [email protected]. Chapter 14 The Perception of Movement Irvin Rock Why does the perception of movement present a problem ? It would seem plausible to believe that when an object moves, its image will move on the retina and this image movement is interpreted by the perceptual system as movement of the object . If this were the case, movement perception would not present a problem . Indeed, insofar as lower animals are concerned, this account may be correct , but as an explanation of the perceptual experience of human observers, it is grossly inadequate. The perceptual experience of movement is analogous to other qualities of sensory experience such as color or size----we perceive movement as a property of the object . The ability to perceive movement is clearly very fundamental in animals; it is necessary for survival . Various animals react to movement but not to stationary objects. In man, movement of an object in the periphery of the field can be detected before its exact form is . apprehended " " Movement is an either -or experience. An object either appears to be moving or it appears to be stationary (although of course its perceived speed may vary ). There is no middle ground . If an object is moving too - slowly - as in the case of the minute hand of a watch it will not appear to move at all, although after a while a change in position is detected . -
Digital Image Processing (In the Ai Era)
DIGITAL IMAGE PROCESSING (IN THE AI ERA) Xiangyu Yu School of Electronic and Information Engineering, South China University of Technology, P. R. China [email protected] LECTURE 2 THE HUMAN VISUAL SYSTEM “Seeing is believing” 3/10/2020 DIGITAL IMAGE PROCESSING 3 CONTENTS The human visual system Image Formation in the Eye Illusions 3/10/2020 DIGITAL IMAGE PROCESSING 4 INTRODUCTION In many image processing applications, the objective is to help a human observer perceive the visual information in an image. Therefore, it is important to understand the human visual system. The percentage of information that flows through visual pathways has been estimated at 90–95% for a typical human without any sensory impairment. The human visual system consists mainly of the eye (image sensor or camera), optic nerve (transmission path), and brain (image information processing unit or computer). It is one of the most sophisticated image processing and analysis systems. 3/10/2020 DIGITAL IMAGE PROCESSING 5 Images taken from Scott E Umbaugh, Digital Image Processing and Analysis: Human and Computer Vision Applications with CVIPtools(3e) (2017) THE HUMAN VISUAL SYSTEM 3/10/2020 Figure The Human Visual System DIGITAL IMAGE PROCESSING IMAGE DIGITAL Umbaugh3E 6 - P.360 HUMAN VISUAL SYSTEM The best vision model we have! Knowledge of how images form in the eye can help us with processing digital images We will take just a whirlwind tour of the human visual system 3/10/2020 DIGITAL IMAGE PROCESSING 7 STRUCTURE OF THE HUMAN EYE 2008) Cornea and sclera keep everything in! The choroid contains all of the blood vessels that serve as nutrition to the eye. -
Extracting the Abstract
Choreographing Time: Developing a System of Screen-less Animation Carol MacGillivray ([email protected]) Thesis Submitted in partial fulfilment of the requirements of the University of London for the degree of Doctor of Philosophy © Carol MacGillivray 17/3/2014 Choreographing time: Developing a system of screen-less animation, March 2014 DECLARATION I hereby declare that except where explicit attribution is made, the work presented in the thesis is entirely my own, including all diagrams and pictures. Carol MacGillivray March 2014 i Choreographing time: Developing a system of screen-less animation, March 2014 ABSTRACT The Diasynchronoscope is an experimental medium that draws on tropes from animation, film and Gestalt grouping principles to create the perception of screen-less apparent motion. Each developing artwork reveals more formalisms and boundaries inherent to the medium. Through documentation and discussion of selected artistic case studies this research interrogates the Diasynchronoscope as an emergent new medium. Formalisms are developed through studio practice and tested in exhibited artworks. The results of these evolving interactions are observed and contextualised using existing frameworks from Film Studies and Psychology. Inside the Diasynchronoscope static objects are grouped according to Gestalt laws and animation principles to create sequential visual cues that, when lit with projected light, demand selective attention; thus creating the illusion of animated movement. The animation is immersive, sharing the same space as the observer so that they perceive a continuous flow of movement that resembles, at a physiological level, interaction with a real-life moving object. The technique has been named the ‘diasynchronic’ technique and the system; the ‘Diasynchronoscope’. -
The D-Scope: Mining the Gap
Networking Knowledge 9(5) Standard Issue (July 2016) The D-Scope: Mining the Gap CAROL MACGILLIVRAY, Goldsmiths, University of London ABSTRACT In 2011, through combining practical research into animation and kinetics with digital projection mapping techniques, two students discovered a way of creating apparent motion without using a camera, film stock or a screen. Originally christened the Diasynchronoscope, in acknowledgement of the rich ancestry of pre-cinematic devices of wonder, the D-Scope technique involves positioning real objects in a blacked-out acoustic space and illuminating them precisely and sequentially; in effect animating through attention. After some years of refinement, the D-Scope immersive system now carries a registered trademark in the UK. It is an innovative medium, still in its infancy that draws on tropes from animation, film and Gestalt grouping principles to create animation freed from the screen. This paper argues that the technique reveals some new ideas about Apparent Motion when it is experienced and perceived on an environmental scale and not framed by a screen. KEYWORDS Apparent Motion, D-Scope, animation, Gestalt, embodiment What is Apparent Motion? We all know what motion or movement is: A transition of something in space over time. Apparent Motion (AM) is where something does not move, but we commonly perceive it as moving. Most of us experience AM daily as it is responsible for how we perceive film or video running at 24 frames per second (or faster) as a continuously moving picture rather than a sequence of stills. What is less understood, despite being exploited as a phenomenon for nearly 200 years, is why we see Apparent Motion at all.