Computer Techniques for Pseudocolor Image Enhancement,

A complex black-and-white image may contain humdreds of gray levels, of which the eye can simultaneously discriminate only about fifteen. However, the eye can distinguish hundreds of colors therefore, if the information content of a black-and-white image can be presented in color, more of that information can be perceived and the image may be more rapidly interpreted. This has led to numerous investigations of ehancement techniques based on color transformation in which each shade of gray, or density level, in the original is seen as a different color in the transformation.