Task 6 Flashcards
Depth perception (25 cards)
Depth cues - monocular cues
- Pictorial
- Occlusion
= one object hides or partially hides another from view
Depth cues - monocular cues
- Pictorial
- Relative Height
= objects that are higher in the field of view are usually farther away; bases closer to horizon seen as being more distant
Depth cues - monocular cues
- Pictorial
- Familiar and Relative Size
= when distance judged based on our prior knowledge of the sizes of objects
Depth cues - monocular cues
- Pictorial
- Perspective Convergence
= something appears to converge in the distance
Depth cues - monocular cues
- Pictorial
- Atmospheric Perspective
= distant objects appear less sharp than nearer objects and often have a slight blue tint
Depth cues - monocular cues
- Pictorial
- Texture Gradient
= several similar objects being equally spaced throughout a scene (marathon runners)
Depth cues - monocular cues
- Pictorial
- Shadows
= can provide information regarding the locations of these objects; ehance three-dimensionality
Depth cues - oculomotor cues
- created by:
- convergence
- accommodation
convergence = inward movement of the eyes that occurs when we look at nearby objects accommodation = change in shape of the lens that occurs when we focus on objects at various distances
Depth cues - monocular cues
- Motion-Produced Cues
- Motion Parallax
= nearby objects appear to glide rapidly past us, distant objects appear to move more slowly
Depth cues - monocular cues
- Motion-Produced Cues
- Deletion and Accretion
= when observer moves sideways, some things become covered, and others become uncovered
Depth cues - monocular cues
- Motion-Produced Cues
- Integrating Monocular Depth Cues
= each cue: “best guess”; monocular depth cues work over different distances
Depth cues - binocular vision
- strabismus
= misalignment of the eyes
—> 3D vision is created by vision with both eyes
Depth cues - binocular vision
- binocular disparity
= difference in the images on the left and right retinas; basis of stereoscopic vision
Depth cues - binocular vision
- binocular disparity
- corresponding retinal points + horopter
?
Depth cues - binocular vision
- binocular disparity
- noncorresponding points + absolute dispartiy
?
Depth cues - binocular vision
- binocular disparity
- crossed + uncrossed disparity
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Perceiving size
- Size Constancy
= fact that our perception of an object’s size is relatively constant even when we view the object from different distances
Illusions of Depth and Size
- Müller-Lyer Illusion
- explanation: misapplied size constancy scaling (= mechanisms that help us maintain stable perception might lea us to illusions)
- conflicting cues theory = perception of line depends on two cues:
(1) actual length of vertical lines
(2) overall length of the figure
Illusions of Depth and Size
- Ponzo Illusion
both animals have same visual angle —> top one appears larger
Illusions of Depth and Size
- Ames Room
- construction of room causes illusion
- explanation based on relative size: perception of size of two people determined by how they fill distance between bottom and top of the room
Illusions of Depth and Size
- Moon Illusion
- apparent distance theory = moon on horizon appears more distant because it is viewed across the filled space of the terrain, which contains depth information; sky: little depth information
- angular size contrast theory = moon appears smaller when it is surrounded by larger objects
Article - Your Brain and Depth Perception
- Von Helmholtz
- brain solves correspondence problem by initially recognizing forms and then comparing extended outlines of the foms —> minimize false matches
Article - Your Brain and Depth Perception
- Julesz
- random-dot patterns
- stereo precedes detection of form
Article - Your Brain and Depth Perception
- Pettigrew
- found that cells were extracting the horizontal shifts and signaling stereo
