Week 7 Color Perception Flashcards
What is color good for? (3 answers)
1) Scene Segmentation
2) Camouflage
3) Perceptual Organization
Scene segmentation
variations in color often
signal object boundaries
Camouflage
animals use this fact to disguise themselves by color markings
Perceptual Organisation
our visual system uses
color to group elements in a scene
What is color? (2 answers)
- visible light forms a narrow band of
frequencies in the electromagnetic spectrum. - within this band, different frequencies (or wavelengths) have different hues, ranging from red (for long wavelength light) to violet
(for short wave length light)
What gives objects their color? (2 answers)
- different objects absorb and reflect
different wavelengths of light - the color also depends on the light
source
Psychological attribute (3 answers)
- Hue (color)
- Brightness (perceived intensity)
- Saturation (how much color or how much white)
Hue, intensity and saturation
Property of light (3 answers)
- wavelength
- intensity
- spectral purity
Theories of color perception (2 answers)
- trichromatic theory
- opponent process theory
Trichromatic theory
there are three receptor types and their combined responses account for all colors:
- blue- sensitive cones
- green- sensitive cones
- red-sensitive cones
Blue-sensitive cones
maximally responsive to short
wavelengths (S-Cones)
Green-sensitive cones
cones maximally responsive to
medium wavelengths (M-Cones)
Red-sensitive cones
maximally responsive to long
wavelengths (L-Cones)
Short wavelength
419 nm
Medium wavelength
531 nm
Long wavelength
558 nm
What is used to determine which wavelengths
they respond to best?
Pigments in the cones
photon bleaches dye and changes chemical format, changes permeability of cell to action potential fires
3 types of dye
more red than green signals red
more complex than 3 outcomes of cones
