Measurement of Gray Scale Reduction in Neutrals and Saturated Colors

An attempt is made to characterize Gray Scale Reduction in a way which is scanner independent. In order to do this, we selected a series of colors and then prepared matchprint patches which produced each of those colors. The selected colors contained neutrals at different luminances. In addition, there were some patches prepared representing saturated colors. For each color a series of patches were prepared. Each patch contained a different amount of black, but each patch of a given series produced the same color under standard illumination (D5000). In this way, we were able to prepare plots for each color showing how much black is required to replace different amounts of process ink. The patches described above were remeasured using different illuminants. By using these measurements, we show how metameric errors in color depend on the amount of gray scale replacement. Theoretical arguments indicate that patches with a high degree of gray scale replacement should show the least amount of metamerism.