6 - Chromatic adaptation and colour constancy

Abstract

With change of illumination the sensitivity of our eyes also changes due to chromatic adaptation, in a way such that the colour of the object remains approximately constant. Various chromatic adaptation models formulated by Hunt, Nayatani and CIE (CIECAM97s and CIECAM02) are discussed in detail. Different light sources can result in different colours of the same object surface. Fortunately, human beings have colour constancy: they perceive the same object colour despite large changes in illumination. A number of colour constancy indices, dependent and independent of chromatic adaptation, are discussed.