The C.I.E. Co-ordinate Systems

Abstract

In 1931 the C.I.E., considering the possibilities mentioned at the end of the preceding chapter, recommended a new system of colour co-ordinates. The introduction of this system, which has been adopted internationally and is still in general use, aimed at establishing uniformity in the specification of colours for which, till that time, various systems were in use, mostly based on measurements by König ³ (in 1890) and sometimes supplemented by those of others. The introduction of the system in 1931 and that of the concept of luminance, as based on the standard luminous efficiency curve, in 1924 (§ 14) were similar moves. In both cases a standardized system based on a selection of existing measurements was introduced. The same criterion therefore now applies for colour measurements as for luminance measurements; i.e. a method is usable provided its results correspond with the values arising from the standardized definitions.