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.