Standard response functions for protanopic and deuteranopic vision

Abstract

The color matches set up by the normal observer can be predicted satisfactorily by 3 functions of wavelength defining the ICI standard observer. It has been found possible by a transformation of coordinate systems to express these 3 functions in a form such that 2 of the 3 pairs also represent the color matches of the two recognized types of red-green-blind observer, the protanope and the deuteranope, within the rather small uncertainties to which they are known. The remaining pair of functions represents, within the comparatively large uncertainties to which they are known, the color matches of the tritanope, a more rare type of observer who confuses reddish blue with greenish yellow. These 3 functions, therefore, serve to relate the color matches made by dichromats to those made by normal trichromats, and so make conveniently accessible the color confusions of avg. dichromatic observers. The use of these 3 functions in the soln. of problems arising in the design of tests for color-blindness is illustrated by solution of 3 such problems, and their connection to theories of color is discussed.