feb 4 Flashcards
(39 cards)
binocular (retinal) disparity
left and right retinal images show noncorrespondence; slight differences in retinal images in each eye
T/F: we always have double vision, we just aren’t always aware
True
anything that has __ disparity is falling on ___
zero; horopter
horopter
imaginary line passing through the plane of fixation; everything falling here have corresponding retinal points
Panum’s fusional area
everything in Panum’s area produce single vision; anything closer to us than Panum’s area produce crossed double images; farther away produce diplopia & uncrossed double vision
stimuli with uncrossed disparity look
farther away
stimuli with crossed disparity look
closer
Wheatstone Stereoscope (1838)
creating depth from binocular disparity using contraption; see small square in front of large square
proof that binocular disparity is a depth cue
Wheatstone Stereoscope, Brewter & Holmes Stereoscope, anaglyph, polarized filters, liquid crystal shutter glasses (rapid temporal alternation)
Brewter Stereoscope (1849)
stereoscope with divider for binocular disparity
Holmes stereoscope (1861)
pictures taken with a stereocamera (lens slightly apart to mimmick the two lenses)
fusion
merging of disparate retinal images in the 2 eyes to achieve single vision
free fusion
technique to view a stereogram without a stereoscope; poor man’s stereoscope; cross fusing and parallel fusing; take two images and combine
cross fusing
type of free fusion; converge eyes; right pic falls on left fovea vice versa
parallel fusing
type of free fusion; diverge eyes; right pic falls on right fovea vice versa
anaglyph
disparity created by separating red and cyan images; coloured filters in glasses; more overlap adds more binocular disparity
in anaglyphs, more overlap adds
more binocular disparity
T/F: order of cyan and red in which eye affects whether the depth is closer to you or further
true
stereopsis
ability to use binocular disparity information as a cue to depth
T/F: everyone has fusion and stereopsis
false; some people have fusion but not stereopsis
liquid crystal shutter glasses
left and right eye images displaced to give binocular disparity over time; rapid temporal alternation of disparate images produces depth perception
stereogram
a pair of stereo pictures consisting of photographs, line drawings, or random-dot patterns
T/F: object recognition does not need to precede stereopsis for depth perception to occur
true (e.g. dot stereograms)
object recognition happens ___ stereopsis extracts depth information
after