color perception how your eye/brain processes colors

Color Perception

How your eye/brain processes colors

Summary

• Human color vision is the result of a) light falling on three different receptors (cones), and b) manipulation and combination of the information from the receptors, called “opponent processing.” Part of the brain’s work here is in compensating for various levels of different hues, which can lead to interesting color phenomena.

Trichromacy of Color Vision

Recall: Rods are sensitive to low lightlevels; cones are sensitive to colors

There are three types of cones, each oneof which is most responsive to a certain range of wavelengths

Trichromacy of Color Vision

wavelength

Res

pons

e

Trichromacy of Color Vision

Your brain is aware only of the response of the photoreceptor; since there is only one type of rod, there can be no color sensitivity

to brain to brain

Trichromacy of Color Vision

cones

rods

Trichromacy of Color Vision

What causes color blindness?

One or two types of cones are missing from the retina

Spectral Complementaries

Colors which when added togetherproduce white light.

This white light appears no differentlyto us than the white light made up ofthe entire spectrum.

C.I.E. Color Diagram

Opponent Processing Theory

Psychological Primary Colors

Why do Lego blocks have the colors they do?

Why do we not describe a coloras “reddish-green” or as “bluish-yellow?”

Opponent Processing Theory

Neural Connections - Chromatic Channels

S I L

y - b

ExcitationInhibition

Neural Connections - Chromatic Channels

S I L

y - b

ExcitationInhibition

r - c

Neural Connections - Chromatic Channels

S I L

y - b

Excitation

w - bkr - g

Colored Shadows

Colored Shadows

Colored Shadows

Colored Shadows

Colored Shadows

Colored Shadows