Retinexes

Definition

Retinexes are theories of color vision that explain how the human brain perceives colors under varying lighting conditions. They suggest that the brain compares information from different parts of the retina to maintain consistent color perception.

5 Must Know Facts For Your Next Test

1. Retinex theory was first proposed by Edwin Land, the inventor of the Polaroid camera.
2. The term 'retinex' is a combination of 'retina' and 'cortex,' highlighting the interaction between the eye and brain in color processing.
3. Retinex theory addresses phenomena like color constancy, where an object's perceived color remains constant despite changes in illumination.
4. Modern retinex algorithms are used in digital image processing to enhance and stabilize colors in photographs.
5. Retinex models suggest that three types of comparisons are made: long-wavelength (red), medium-wavelength (green), and short-wavelength (blue) light.

Review Questions

• Who first proposed the Retinex theory?
• What does Retinex theory help explain about human vision?
• How is Retinex theory applied in modern technology?

Related terms

Color Constancy: The feature of the human color perception system which ensures that the perceived color of objects remains relatively constant under varying illumination conditions.

Trichromatic Theory: A theory of color vision stating that there are three types of photoreceptors in the retina, each sensitive to one of three primary colors: red, green, or blue.

Opponent Process Theory: A color vision theory that suggests colors are perceived through opposing pairs: red-green, blue-yellow, and black-white. This theory helps explain afterimages and certain aspects of color blindness.