Colour image processing is divided into two main areas: full colour and pseudo-colour processing. In the former group, the images are normally acquired with a full colour sensor such as a CCTV camera. In the second group, a colour is assigned to a specific monochrome intensity or combination of intensities. People perceive colours that actually correspond to the nature of the light reflected from the object. The electromagnetic spectrum of the chromatic light falls in the range of 400-700 nm. There are three quantities that are used to describe the quality of a chromatic light source: radiance, luminance and brightness
