Week 9

Question 1

What is Euclidian Geometry?

Answer 1

• Parallel lines remains parallel as the extend in space.
• objects same Space size and shape
• images in the retina are non-euclidean

Question 2

What is binocular summation?

Answer 2

The combination of signals from each eye in ways that make performance on tasks better

Question 3

What is binocular disparity?

Answer 3

The differences between the two retinal images of the same scene

Question 4

What are depth cues and the two types?

Answer 4

Information about the 3D space

• Monocular: world viewed with one eye
• Binocular: world vied with both eyes

Question 5

Monocular depth cues properties?

Answer 5

Occlusion 
Size and portion
aerial perspective 
Linear perspective 
motion parallax
the eye

Question 6

What is occlusion?

Answer 6

a cue to relative depth order in which one objects obstructs the view of another

Question 7

There are two types of depth cues in monocular vision. what are they?

Answer 7

Metrical: provides quantitative info about distance and 3D

Non-metrical: Provides info about the depth order

Question 8

What are the different size and portions of monocular depth cues?

Answer 8

• Relative size: Size between items (how close and item is
• Relative hight: Below horizon = closer / Above horizon = Further
• Texture gradient: based on geometric fact that items of the same size form smaller images when further away

Question 9

What is aerial perspective?

Answer 9

depth cue based on the implicit understanding that light is scatted by the atmosphere

Question 10

What is linear perspective?

Answer 10

Lines that are parallel in 3D will appear to converge

Question 11

What is a vanishing point?

Answer 11

The apparent point at which parallel lines receding in depth converge

Question 12

What are motion cues or motion parallax?

Answer 12

Images closer to the observer move faster across the visual field? (relative)

Question 13

What are three properties of the eye itself?

Answer 13

Accommodation: eye change focus
Convergence: eyes to turn inwards (near object)
Divergence: eyes turn outwards (far objects)

Question 14

What are corresponding retinal points

Answer 14

Points on the retina of each eye where the monocular retinal images of a signal object are formed are a there same distance from the fovea in each eye

Question 15

What is binocular disparity?

Answer 15

difference between the two retinal images of the same scene

Question 16

What is the horopter?

Answer 16

The location of objects whose images lie on the correspond points (zero disparity)

Question 17

Whats the Vieth-Müller circle?

Answer 17

surface of zero disparity or location of objects whose images fall on geometrically corresponding points in eyes

Question 18

Objects on the horopter are …

Answer 18

seen as single images when views with both eyes

Question 19

What is the Panum’s fusional area?

Answer 19

the region of space in-front and behind the horopter.

Question 20

Objects closer and futher away from the horopter:

Answer 20

Fall on non corresponding points in the two eyes and are seen as two images.

Question 21

What is diplopia ?

Answer 21

Double vision. if visible in both eyes.

Question 22

What is crossed disparity?

Answer 22

disparity created by the object in front of the place of horopter
Image displaced left in the right eye vice versa

Question 23

What is uncrossed disparity?

Answer 23

disparity created by the object behind the plane of horopter

image displaced right in the right eye vice versa

Question 24

What is free fusion?

Answer 24

The technique of converging or diverging the eyes in order to view a stereogram without a stereoscope

Question 25

What is Stereoblindness?

Answer 25

An inability to make use of binocular disparity.

Question 26

What is Correspondence problem?

Answer 26

Figuring out which bit of the image in the left eye should be matched up with which bit in the right eye

Question 27

What are some ways to solve the correspondence problem?

Answer 27

Bluring the image: Reducing number of features
Uniqueness constraint: object featured once in each retina
Continuity constraint: disparity at neighbouring point should be familiar.

Question 28

How is stereopsis implemented in the human brain?

Answer 28

zero disparity

tuned to particular binocular disparity

Question 29

What is binocular rivalry?

Answer 29

competition between the two eyes for control of visual perception

Question 30

In humans, evolution may have favored two eyes facing forward because it statistically increases the chance of detecting a stimulus. The combination of signals from the two eyes that enhances performance on many tasks is called:

Answer 30

Binocular summation

Question 31

Using the depth cue of _______ you can tell how far away something is based on how much detail is visible in the elements on the ground between you and the object.

Answer 31

Texture gradient

Question 32

Suppose you are looking at a road that recedes into the distance. Which depth cue describes the way the edges of the road seem to converge in the retinal image?

Answer 32

Linear perspective

Question 33

When an artist paints trees on a landscape extending into the distance, she distributes the trees vertically to simulate _______, and makes trees that are farther away smaller, simulating _______.

Answer 33

Relative height; relative size

Question 34

When driving in a car, the fact that light posts by the side of the road move faster across your eye than do distant buildings is the visual cue known as:

Answer 34

Motion paralax

Question 35

The difference between crossed disparity and uncrossed disparity is that crossed disparity involves objects that are _______ the plane of fixation, while uncrossed disparity involves objects that are _______ the plane of fixation.

Answer 35

in front of; behind