Spectral Sensitivities for Color Separation.

To ensure that colors which look alike shall photograph alike, the spectral sensitivities used in the color-separation stages must conform to a set of visual color-mixture curves. There are an infinite number of sets of visual color-mixture curves, but, in practice, the spectral sensitivities do not usually conform to any one of these sets. It is convenient to be able to specify which set of color-mixture curves most closely approximates a given color-separation procedure so that the seriousness of non-conformity may be evaluated and selection of better spectral sensitivities can sometimes thereby be achieved. Neugebauer described a method for doing this in part. This paper extends Neugebauer's methods to encompass all of these aims and demonstrates the procedures involved in many practical situations.