visual perception principles (Gestalt, depth cues, and visual constancies)

what is perceptual constancy

tendency to maintain stable perception of stimulus even when properties on retina change

types of perceptual constancies

size constancy, shape constancy

size constancy

object perceived to have same size even as image moves closer/further from us

size constancy eg

2 ppl swimming one may look smaller but is actually just further away

shape constancy

object perceived to maintain shape despite changing perspective - scenery

shape constancy eg

clock moving at diff angles is perceived as same shape even if the shape differs with perspective

what are the Gestalt principles

figure ground organisation, closure, similarity, proximity

figure ground organisation

perceive stimuli with focus on object - figure- against background - ground-

figure and ground seperated by imaginary contour

figure ground eg

2 men’s face (black) and vase (yellow) in one image

closure

when image perceived as whole when it’s incomplete

closure eg

zebra with white paper, soccer ball

similarity

tends to put similar items in single group

similarity eg

similar size, shape, colour

proximity

tend to put parts of pattern close together in group

depth perception types

binocular, monocular

what is depth perception

ability to accurately judge 3D space and distance using enviro cues

depth perception retina

image produced on retina only 2D rely on cues for 3D

binocular

both eyes used to determine distance

cues used in binocular

reintal disparity, convergence - eye measures distance moved

monocular

one eye judges distance and depth

cues used for monocular

accomodation, pictorial depth cues

types of pictorial depth cues

linear perspective, interposition, texture gradient, relative size, height in visual field

linear perspective

parallel lines appear to meet at some point in distance - vanishing point - lines seem to merge

interposition

one object partially covers another - creates app that object covered is further away

texture gradient

gradual change in app - coarse to fine

coarse = closer - more distinct

relative size

gives ability to measure how far away object is by judging how big/small it is in relation to other object

height in visual field

objects closer to horizon appear to be further away - all objects same size