More on “Color Constancy”
June 11th, 2005 | No Comments »The retina in effect performs a “three color separation” in detecting the visible spectrum (the range of wavelengths of the electromagnetic spectrum available to the eye). First the long and short wavelength limits of the spectrum (~700 and 400 nm) are geometrically determined by cone/cone and rod/rod dimensions. Then, in the admixture of cones and rods extending from the fovea, the exact mid-band point of the spectrum (at 550 nanometers) is again geometrically determined by cone/rod dimensionality. The sensation of color derives from a ratioing of the intensity of wavelengths incident on the retina on either side of this mid-band point encoded as brightnesses (not wavlength!) referenced to the 550 nm point. This is an exact geometric explanation of the behaviour within the eye that Edwin Land proposed must be present.
