Module 8 Unit 13
Atmospheric perspective
Objects in the distance appear blurred and tinged with blue
Corresponding Points
Refers to a situation in which a point on the left retina and a point on the right retina would coincide if the two retinae were superimposed
Random-Dot Stereograms
Stereograms in which the images consist of a randomly arranged set of black and white dots, with the left-eye and right-eye images arranged identically except that some of the dots are moved to the left or the right in one of the images, creating either a crossed or an uncrossed disparity
Strabismus and stereopsis
Strabismus- one eye is turned in or out too much; images won't fall the same on the fovea and don't see the same thing with both eyes. The brain will suppress the info from the eye that isn't normal. Stereopsis depth cues can be lost if strabismus is not corrected at an early age
Familiar size
The cue whereby knowing the retinal size of a familiar object at a familiar distance allows us to use that retinal size to infer distance
The Ponzo Illusion
The illusion in which two horizontal lines are drawn one above the other; both lines are on top of two inwardly angled vertical lines; the top line, where the two vertical lines are closer together, looks longer
The Müller-Lyer Illusion
The illusion where a line that has two lines going away at an angle looks longer than a line of the same length but the end lines angle back across the main line
The Moon Illusion
The illusion where the moon looks larger when it is near the horizon than it does when overhead
Relative size
The more distant an object, the smaller the image will be on the retina.
Three-Dimensional Movies
The movie has separate frames for the same movie so that each eye gets a different image of the movie to mimic binocular disparity that we see in the world. The brain perceives the image by combining the two images together to get a 3D image.
Size Constancy
The perception of an object as having a fixed size, despite the change in the size of the visual angle that accompanies the change in distance
Linear perspective
The pictorial depth cue that arises from the fact that parallel lines appear to converge as they recede into the distance. (i.e. railroad tracks)
The Horopter
The region in a space where the two images form an object fall on corresponding location on the two retinae
Size-distance invariance
The relation between perceived size and perceived distance, whereby the perceived size of an object depends on its perceived distance, and the perceived distance of an object may depend on its perceived size
Binocular Suppression
(i.e. monster demo, see a hole inside your hand) brain superimposes what is interesting and combines both images. The brain is suppressing part of your hand and inputs what the other eye is seeing.
Forced Perspective Illusions
(i.e. woman looking giant but not really giant) The picture is taken in an accidental viewpoint to create an illusion. Used a lot in movies like Lord of the Rings to create the illusion that some people are much smaller that others.
Development of Stereopsis
4 months of age babies show development of stereopsis, 5 months they are comparable to adults at using difference in two retinas to understand depth. The eyes need to correct abnormal eye coordination to fire neurons properly.
Binocular Disparity
A binocular depth cue because our two eyes are in different locations in our head and therefore have slightly different views of the world
Random-dot Stereograms as Anaglyphs
Different sets of dots are diff. colors that make you see two X's that float on the image.
Motion parallax
A monocular depth cue that arises from the motion of a person in the environment. Faster moving objects are closer to us; slower moving objects are farther away.
Texture gradients
A monocular depth cue that occurs because textures become finer as they recede in the distance.
Shadows and shading
An object in front of its shadow, and the angle of the shadow can provide some information about how far the object is in front of the background
Relative height
Objects closer to the horizon are seen as more distant and farther away from the horizon as closer to us.
Monocular Depth Cues
Depth cues that require only one eye
Ebbinghaus Illusion
Illusion of size due to contrast of objects by induction from the objects near it (i.e. larger circles surrounding or smaller circles surrounding) Illusion only works for our "what" pathway
Monocular Pictorial Cues
Information about depth that can be inferred from a static picture
Occlusion
It happens when one object partially hides or obstructs the view of a second object.; we infer that the hidden object is farther away from us than the object that obstructs it
The Anatomy and Physiology of Binocular Perception
Neurons inside of the V1 pay attention to the left and right eye together. Disparity neurons detect the difference between the two eyes when an object doesn't fall on a correspondence point.
The Ames Room Illusion
You see the same person as smaller in one corner of the room compared to the other. Smaller images on your retina because the room is not normal size or shape. The rooms features help trick you into thinking the room is normally shaped.
Vergence
convergence and divergence; occurs when you bring focus from far to close eyes accommodate by converging or diverging to look from close to farther away using muscles in your eyes.
Virtual Reality
each eye is stimulated separately giving a strong sense of 3D
Wheatstone Stereograph
each eye saw separate images causing the brain to think it was seeing one combined scene.
Anaglyph
images that have offset by taking two pictures of the same thing, one taken with only red image, and one with only green image. Print the red and green image on top of each other to create a 3D image.
Stereograms
instrument that allows you to see 3D based on 2D photographs (i.e. wheatstone stereograph)
Binocular Rivalry
perceptual alternation occurs where you see what is in your right eye at one moment and left eye at another moment bc your eyes are competing to see each separate image.
Deletion
the gradual occlusion of a moving object as it passes behind
Accretion
the gradual reappearance of a moving object as it emerges from behind another object.
Optic flow
the motion depth cue that refers to the relative motions of objects as a person moves forward or backward in a scene
Accommodation
the process of adjusting the lens of the eye so that one can see both near and far objects easily.
Stereopsis
the sense of depth that we perceive from the visual system's processing of the comparison of the two different images from each retina.