lecture 4- depth perception

Question 1

state: the visual system uses optical information in the “2-D” retinal images to compute object shape

Question 2

what does depth perception register?

Answer 2

depth perception registers the distance between object and observer

Question 3

what are sources of depth information?

Answer 3

depth cues

Question 4

what are the two different categories of depth cues?

Answer 4

• monocular
  -binocular

Question 5

monocular visual depth cues

Answer 5

• monocular visual depth cues can be provided by both eyes or by one eye alone. monocular depth cues may be static or motion depth cues.
• binocular cues rely on comparison of input from each eye to yield depth information

Question 6

what are the 4 parts of monocular cues?

Answer 6

-pictorial cues
-clarity and elevation
-accommodation
-kinetic cues

Question 7

what are the 3 parts of pictorial cues?

Answer 7

• size
• interposition
• lightning and shadow

Question 8

size- mono pictorial depth cues

Answer 8

• as the distance between object and observer increases, the retinal image becomes smaller, hence the size of a familiar object provides a depth cue
• perceived size is scaled in terms of perceived distance (size constancy)

Question 9

interposition- monocular pictorial depth cues

Answer 9

• when one object occludes part of another, the partially occluded object is perceived as more distant, this is called interposition

Question 10

lighting and shadow- monocular pictorial depth cues

Answer 10

??????

Question 11

clarity and elevation including of …

Answer 11

• aerial and linear perspective
  -texture

Question 12

aerial perspective

Answer 12

distant objects appear less clear than close objects is a depth cue

Question 13

linear perspective

Answer 13

linear perspective is a depth cue provided by line convergence

Question 14

illustrating perspective in art

Answer 14

• linear perspective was discovered by Italian artists during the 15th century
• linear perspective enabled artists to capture depth and 3-D perspective on a 2-D surface

Question 15

texture- clarity and elevation

Answer 15

• texture gradients provide depth information (gradient of image size/ texture perspective)

Question 16

what are errors in perceived size attributed to?

Answer 16

monocular depth cues

Question 17

in the ponzo illusion what do the perspective cues imply?

Answer 17

imply the distance between regions of figure

Question 18

what do these cues affect?

Answer 18

these cues affect size judgement of objects located in these regions

Question 19

integration of depth perception

Answer 19

• various depth cues provide unique information that is processed additively
• depth perception is degraded when depth cues provide conflicting information

Question 20

accommodation?????

Question 21

what is motion parallax and how does it occur?

Answer 21

• motion parallax is a relative apparent motion that provides and effective depth cue
• motion parallax can occur by observer movement relative to an object, or when observer is still and the object moves

Question 22

what are the 2 parts to binocular depth cues?

Answer 22

• convergence
• disparity

Question 23

what does binocular vision allow humans to do?

Answer 23

binocular vision allows humans to discriminate very small differences in relative depth

Question 24

what is stereopsis?

Answer 24

depth perception that relies on disparities between the views of the left and right eyes

Question 25

what is retinal disparity and what does it provide?

Answer 25

- retinal disparity is the difference in lateral separation between objects seen by the left and right eyes - retinal disparity provides the information for stereoscopic depth perception