????????? (cue approach to depth perception)

1
Chapter 10

• ?????

2
?????????(cue approach to depth perception)

• ??????(proximal stimulus)???????(distal
  stimulus)???????(cues ),???????????????????????,??
  ??????

3
??????(Oculomotor cues)

• ?????????????????????,????????
• ??????(????)
• Convergence
• ??????,???????

• ????convergence ??,????????
• ????

4
??????(Oculomotor cues)

• Accommodation
• ???????,????????????
• ?????,??????
• ????

5
???? (monocular cues)

• ????(pictorial cues)
• Albertis window

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???? (monocular cues)

• ??(occlusion)
• ????????
• ??????
• ????
• ???????????
• ??,??????????,?????????

7
Fig. 8-3, p. 170
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???? (monocular cues)

• ????
• ????? (demo-monster)
• ????(perspective convergence)
• ?????

9
???? (monocular cues)

• ?????
• ??????????
• ???????????

10
???? (monocular cues)

• ????(atmosphere perspective)
• ???????

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Fig. 8-5, p. 171
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???? (monocular cues)

• ????
• ????

13
???? (monocular cues)

• ??
• ??????????????????

???????????????
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• ????(movement-produced cues)
• ?????????????(??)

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• ????(motion parallax)
• ???????,???????link
• ????????,??????????????????,??????????

16

• Deletion accretion

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Fig. 8-10a, p. 173
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Fig. 8-10b, p. 173
19

• Table 8.1 Range of effectiveness of different
  depth cues

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??????

• ????(Binocular disparity)
• ????????

21

• Figure 8.11 Location of images on the retina for
  the Two Eyes Two Viewpoints demonstration.
  (a) Both images are on the fovea when the left
  eye is open. (b) The images are on different
  places on the retina when the right eye is open.

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??????

• ???(stereopsis)
• ???(corresponding retinal points)
• ???????????????

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• horopter
• ???????,?????,???????????????????

• Figure 8.13 (a) When the lifeguard looks at
  Frieda, the image of Frieda, Susan, and Harry
  fall on corresponding points on the lifeguards
  retinas, and the images of the other swimmers
  fall on noncorresponding points. (b) The
  locations of the images of Susan, Frieda, and
  Harry on the lifeguards retina.

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• ??horopter????,????????????(noncorresponding
  points)
• ?????(angle of disparity)?????(absolute
  disparity)
• ?horopter??,?????

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Horopter
Absolute disparity for Carole (how far an object
is from the horopter)
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Absolute disparity for Frieda
Horopter
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• ?????(crossed disparity) ?? horopter????????????,
  ?????horopter?
• ??????(uncrossed disparity)?? horopter???????????
  ??(????????) ,?????horopter?

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• Relative disparity is the difference between the
  absolute disparity of two objects.
• Absolute disparity
• Frieda 0
• Carole 26
• Relative disparity 26 0 26
• Offering an advantage as an observer shifts his
  fixation

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• Stereoscope (1800s)

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• Figure 8.16 The two images of a stereoscopic
  photograph. The difference between the two
  images, such as the distances between the front
  cactus and the window in the two views, creates
  retinal disparity. This creates a perception of
  depth when (a) the left image is viewed by the
  left eye and (b) the right image is viewed by the
  right eye.

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Fig. 8-18, p. 176
32

• 3-D movies
• A polarized filter allows only light travelling
  in one position to pass through. It is made of
  parallel micro-sized slits that block out all but
  one position of wave.
• A wave in the vertical planepasses through a
  verticalpolarized filter.A wave in the
  horizontal planepasses through a
  horizontalpolarized filter, but would not
  beable to pass through a verticalpolarized
  filter.

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• There are two types of filters in 3-D glasses
  (i.e. vertical and horizontal). So, one side
  allows only light travelling in one position to
  pass through while the other side allows light of
  the opposite position to pass.
• 3-D movies are filmed with a stereoscopic camera
  that records video much like how the Pathfinder
  IMP above records images. When a 3-D movie is
  played, two projectors are used to display both
  perceptions. Each projects a video polarized
  (with a filter) onto the screen. Wearing the 3-D
  glasses, each eye can only take in light from one
  of the projectors. Therefore, each eye receives a
  different image. Your brain interprets these two
  separate images and combines them into one 3-D
  picture.
• Next time you view a 3-D movie, take two set of
  glasses. Place the right-eye filter and place it
  over the left-eye filter. It's dark. That because
  the vertical and horizontal filters are combined
  and no light can enter. They cancel each other.

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• ????

35

• ????

36
Fig. 8-17, p. 176
37
Also see demo
38

• ??????????
• ??????(Random dot stereogram)(Julez, 1971)
• ??????????

39

• ???????match?
• ????(The correspondence problem)
• ??????????
• RDS ??

40
Depth Perception in Other Species

• Animals use the range of cues that humans use.
• Frontal eyes, which result in overlapping fields
  of view, are necessary for binocular disparity.
• Lateral eyes, which do not result in overlapping
  fields of view, provide a wider view.
• This is important for watching for predators.

41
Depth Perception in Other Species

• Locusts use motion parallax to judge distance.
• Bats use echolocation to judge the distance of
  objects in the dark.
• They emit sounds and note the interval between
  when they send them and when they receive the
  echo.

42

• Figure 10.22 When a bat sends out its pulses, it
  receives echoes from a number of objects in the
  environment. This figure shows the echoes
  received by the bat from (a) a moth located about
  half a meter away (b) a tree, located about 2
  meters away and (c) a house, located about 4
  meters away. The echoes from each object return
  to the bat at different times, with echoes from
  more distant objects taking longer to return. The
  bat locates the positions of objects in the
  environment by sensing how long it takes the
  echoes to return.

43
?????????

• A neuron in the parietal cortex of a monkey

• Figure 8.20 Top gradient stimuli. Bottom
  response of neurons in the parietal cortex to
  each gradient. This neuron fires to the pattern
  in (c), which the monkey perceives as slanting to
  the left. (From Tsutsui et al., 2002, 2005.)

44

• ??????(Binocular depth cell)????????(disparity
  selective cell)
• ??????????????

• Figure 8.21 Disparity tuning curve for a
  disparity-sensitive neuron. This curve indicates
  the neural response that occurs when stimuli
  presented the left and right eyes create
  different amounts of disparity. (From Uka
  DeAngelis, 2003.)

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• ??????,????????????
• ???(sensitive period)???

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Connecting Binocular Disparity and Depth
Perception

• Experiment by Blake and Hirsch
• Cats were reared by alternating vision between
  two eyes.
• Results showed that they
• had few binocular neurons.
• were unable to use binocular disparity to
  perceive depth.

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• Neural Responding Depth Perception
• DeAngelis et al. (1998)
• Monkey training depth created by images with
  different absolute disparity to each eye
• Monkey shifted its depth judgment because of a
  different group of disparity-selective neurons
  activated.
• Primary visual cortex ? Ventral and dorsal streams

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???? (size perception)

• ???????????

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• Figure 8.25 (a) The visual angle depends on the
  size of the stimulus (the woman in this example)
  and its distance from the observer. (b) When the
  woman moves closer to the observer, the visual
  angle and the size of the image on the retina
  increases. This example shows how halving the
  distance between the stimulus and observer
  doubles the size of the image on the retina.

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(No Transcript)
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• Figure 8.26 The thumb method of determining the
  visual angle of an object. When the thumb is at
  arms length, whatever it covers has a visual
  angle of about 2 degrees. The womans thumb
  covers half the width of her iPod, so we can
  determine that the visual angle of the iPods
  total width is about 4 degrees.

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Fig. 8-27, p. 182
53

• Holway Boring (1941)
• ???????????,????????????
• ?????????(?????10ft?)???????????

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• 1-????????2-??3-?????4-???????
• ?????????????,????????

?????????????
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????? ??????????

• ?????????????
• ??????????????

?????
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• ?????(size constancy)
• ??????,????????????
• ???????????????-??????(size-distance scaling
  mechanism)
• demo
• SK(R x D)
• S-????,K-??, R-??????,D-??

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• Emmerts law
• Familiar size and texture gradient
  information????????????

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Fig. 8-30, p. 183
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Emmerts lawK(R x D) S
Fig. 8-31, p. 184
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Fig. 8-32, p. 184
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Fig. 8-33, p. 185
62
??

• Muller-Lyer illusion
• ??????????? SK(R x D)

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• ???????????????

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• ??????????????
• ??????????

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• Ponzo illusion
• ???????????

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• Ames room

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Fig. 8-40, p. 187
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• Figure 8.41 The Ames room, showing its true
  shape. The woman on the left is actually almost
  twice as far away from the observer as the woman
  on the right however, when the room is viewed
  through the peephole, this difference in distance
  is not seen. In order for the room to look
  normal when viewed through the peephole, it is
  necessary to enlarge the left side of the room.

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• ????(Moon illusion)
• ??????(apparent distance theory)
• ??????????????,??????,??????????
• ????????(angular size contrast theory)
• ??????,??????,??????

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2005/6/23
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• Figure 8.42 An artists conception of the moon
  illusion showing the moon on the horizon and high
  in the sky simultaneously.

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• Figure 8.43 When observers are asked to consider
  that the sky is a surface and are asked to
  compare the distance to the horizon (H) and the
  distance to the top of the sky on a clear
  moonless night, they usually say that the horizon
  appears farther away. This results in the
  flattened heavens shown above.

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• ????(apparent distance)??
• ?????,??????
• ??????
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• ????
• ??
• ????

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• ?????????????????

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• ?????????????????

• Figure 8.44 Results of Witt et al.s (2004)
  experiment. For each of the conditions, larger
  distance estimates were associated with greater
  effort.