COLOR VISION
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COLOR VISION Shirmeen Ijaz
description
COLOR VISION. Shirmeen Ijaz. COLOR. The most technically accurate definition of color is: " Color is the visual effect that is caused by the spectral composition of the light emitted, transmitted, or reflected by objects.“. - PowerPoint PPT Presentation
Transcript of COLOR VISION
COLOR VISION
Shirmeen Ijaz
COLOR The most technically accurate definition
of color is:"Color is the visual effect that is caused by the spectral composition of the light emitted, transmitted, or reflected by objects.“
The human eye senses this spectrum using a combination of rod and cone cells for vision.
Three types of cone cells exist in your eye, with each being more sensitive to either
1)S-cone: Short (S) wavelength light. 2) M-cone: Medium (M) wavelength
light. 3) L-cone: Long (L) wavelength light.
Color-Processing in Vision
BLUE CONES 2% OF THE CONE POPULATION
•Found mostly outside the fovea
GREEN CONES 32% OF THE CONE POPULATION
•Packed into the fovea
RED CONES 64% OF THE CONE POPULATION
•Packed into the fovea
Color can only exist when three components are present:
1) a viewer, 2) an object, 3) light. Although pure white light is perceived as
colorless, it actually contains all colors in the visible spectrum. When white light hits an object, it selectively blocks some colors and reflects others; only the reflected colors contribute to the viewer's perception of color.
1. All the "invisible" colors of sunlight shine on the apple.
2. The surface of a red apple absorbs all the colored light rays, except for those corresponding to red, and reflects this color to the human eye.
3. The eye receives the reflected red light and sends a message to the brain.
COLOR WHEEL
THEORIES OF COLOR VISION:-
1) Trichromatic theory 2) Opponent process
theory
Trichromatic theory Given by Thomas Young. Primary colors Red Green Blue Every color (hue) can be created by
blending light of the three primary colors in differing proportions
“Blue”
“Green”
“Red”
Blue
Wavelength Input Cone Signal to Brain
“Blue”
“Green”
“Red”
Green
Wavelength Input Cone Signal to Brain
Theories of Color Vision: Trichromatic Theory
“Blue”
“Green”
“Red” Red
Wavelength Input Cone Signal to Brain
Theories of Color Vision: Trichromatic Theory
“Blue”
“Green”
“Red”
Yellow
Equal Parts Red and Green =
Wavelength Input Cone Signal to Brain
Theories of Color Vision: Trichromatic Theory
“Blue”
“Green”
“Red”
Yellow
Equal Parts Red and Green =
Wavelength Input Cone Signal to Brain
Theories of Color Vision: Trichromatic Theory
“Blue”
“Green”
“Red”
Yellow
Equal Parts Red and Green =
Wavelength Input Cone Signal to Brain
Theories of Color Vision: Trichromatic Theory
Opponent-Process theoryGiven by Ewald Heringhe noted that there are
certain pairs of colors one never sees together at the same place and at the same time.
Red/Green Yellow/Blue Black/White If one color is
stimulated, the other is inhibited.
According to Hering, there are 3 types of color receptors, but they are not sensitive only to red, green and blue.
He also claimed, a color could be a reddish yellow or a bluish green, but not a reddish green or a bluish yellow.
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