Minimum Perceptible Differences in the Colour Reproduction of Photographic Prints

This work was funded by the Science and Engineering Research Council and Kodak Ltd.

Abstract

The aim of this work was to investigate observer perceptibility of small colour differences in the colour reproduction of reflection prints produced using a negative/positive photographic system. Comparison of the experimental results, in the form of hue-oriented and non hue- oriented ellipses, was made with MacAdam ellipses, CIELAB unit ellipses and ellipses derived from the CMC (l:c) colour difference formula, in the 1976 CIELAB colour space. It was found that the CMC (l:c) ellipses fitted the hue-oriented ellipses more closely than the CIELAB unit el-lipses, there being no significant differences between the hue-oriented and the non hue-oriented ellipses. There was, however, a significant difference between MacAdam ellipses and the non-hue oriented experimental ellipses. It was therefore concluded that the CMC (l:c) colour difference formula could be used to predict the tolerance ellipse for any colour centre, under the conditions used in this work. The minimum perceptible difference was found to be equivalent to $$\Delta E_{cmc}^{*}=2$$, a CMC colour difference (ΔE*) of two units.

Notes

This work was funded by the Science and Engineering Research Council and Kodak Ltd.