2. Depth Cues Pictorial Depth Cues: aspects of 2D images that imply depth
Physiological Depth Cues: Proprioception in ocular muscles indicates accommodation and convergence
Motion Depth Cues: foreground and background move in opposite directions
Stereoscopic Depth Cues: disparity between two retinal images indicates distance

3. Pictorial Depth Cues
Texture gradient

4. Pictorial Depth Cues
Height in the plane

5. More Depth Cues Pictorial Depth Cues Physiological Depth Cues
Motion Parallax
Stereoscopic Depth Cues

6. Physiological Depth Cues
Two Physiological Depth Cues
accommodation
convergence

7. Physiological Depth Cues
Accommodation

8. Physiological Depth Cues
Convergence

9. Physiological Depth Cues
Convergence
small angle of convergence = far away
large angle of convergence = near
What two sensory systems is the brain integrating?
What happens to images closer or farther away from fixation point?

10. Physiological Depth Cues
Convergence and accommodation are reflexively linked
Under what circumstances might this be a problem?

11. Motion Depth Cues
Motion
Parallax

12. Motion Depth Cues
Parallax

13. Motion Depth Cues Parallax
points at different locations in the visual field move at different speeds depending on their distance from fixation

14. Motion Depth Cues
Parallax

15. Seeing in Stereo
Seeing in Stereo

16. Seeing in Stereo
It’s very hard to read words if there are multiple images on your retina
It’s very hard to read words if there are multiple images on your retina

17. But how many images are there on your
Seeing in Stereo
It’s very hard to read words if there are multiple images on your retina
It’s very hard to read words if there are multiple images on your retina
But how many images are there on your
retinae?

18. Binocular Disparity Your eyes have a different image on each retina
hold pen at arms length and fixate the spot
how many pens do you see?
which pen matches which eye?

19. Binocular Disparity Your eyes have a different image on each retina
now fixate the pen
how many spots do you see?
which spot matches which eye?

20. Binocular Disparity
Binocular disparity is the difference between the two images

21. Binocular Disparity
Binocular disparity is the difference between the two images
Disparity depends on where the object is relative to the fixation point:
objects closer than fixation project images that “cross”
objects farther than fixation project images that do not “cross”

22. Binocular Disparity
Corresponding retinal points

23. Binocular Disparity
Corresponding retinal points

24. Binocular Disparity
Corresponding retinal points

25. Binocular Disparity
Corresponding retinal points

26. Binocular Disparity
Points in space that have corresponding retinal points define a plane called the horopter
The Horopter

27. Binocular Disparity
Points not on the horopter will be disparate on the retina (they project images onto non-corresponding points)

28. Binocular Disparity
Points not on the horopter will be disparate on the retina (they project images onto non-corresponding points)
The nature of the disparity depends on where they are relative to the horopter

29. Binocular Disparity points nearer than horopter have crossed disparity
points farther than horopter have uncrossed disparity
The Horopter

30. Binocular Disparity
Why don’t we see double vision?

31. Binocular Disparity Why don’t we see double vision?
Images with a small enough disparity are fused into a single image