MEASURED COLOR-DIFFERENCE AND THE ACCEPTABILITY OF PHOTOGRAPHIC COLORPRINTS

The relations between an overall Colour Reproduction Index (CRI), a me an colour difference, CIELAB Delta E(ab), and the acceptability of co lour prints are investigated and quantified for two scenes at a range of controlled hue and lightness excursions from standard print criteri a. This paper extends the analysis of experimental results to show lin ear relationships between CRI and CIELAB Delta E(ab), and between eac h of these measures and the acceptability of reproductions. The relati onships are, however, both complex and noisy. Print lightness is shown to be a more significant quality parameter than is allowed for in the calculation of the overall CRI and CIELAB Delta E(ab). It is also sh own that hue is a scene-specific determinant of print acceptability. C onclusions are drawn concerning the relative usefulness of the two dif ferent measures of colour difference: CRI and CIELAB Delta E(ab).