Lecture 16 Flashcards
What is a cue approach to depth perception?
A cue approach to depth
perception focuses on information
in the retinal image that is correlated
with depth in the scene
- We learn the connection between
cue and depth (e.g. occlusion) - Association becomes automatic
through repeated exposure
What are oculomotor cues?
based on sensing
the position of the eyes and muscle
tension
Describe convergence
inward movement of
the eyes when we focus on nearby
objects
Describe accommodation
the shape of the
lens changes when we focus on
objects at different distances
Describe monocular cues
information that
can be based on the image from a
single eye
Describe pictorial cues
sources of depth information that come from 2-D images, such as
pictures
Describe occlusion
when one object partially covers another
Describe relative horizon
- Objects below the horizon (an imaginary horizontal line that is at the same level as the observer,
or ‘eye-level’) that are higher in the field of vision are more distant (motorcycle 2 vs. motorcycle 1) - Objects above the horizon that are lower in the visual field are more distant (cloud 4 vs. cloud 5)
What is relative size?
when objects are
equal size, the closer one will take
up more of your visual field
Describe perspective convergence
parallel lines appear to come together in the
distance
Describe atmospheric perspective
distance objects appear more ‘fuzzy’
* Occurs because the farther away something is, the
more air/particles we have to look through to see it
- Farther objects also tend to appear more ‘blue’ (for
the same reason the sky looks blue, i.e. our
atmosphere preferentially scatters short wavelengths
and looking ‘through’ more of increases the
‘blueness’ this imparts on our perpeption
Describe texture gradient
equally spaced elements are more
closely packed as distance increases
Describe shadows
helps enhance depth by indicating
where objects/features are located
Describe motion parallax
close objects in
direction of movement glide rapidly
past but objects in the distance
appear to move slowly
Describe deletion and accretion
- Deletion and accretion: objects are covered or uncovered as we move relative to them
- Deletion refers to covering an object
- Accretion refers to uncovering an object