OBSERVER VARIABILITY IN METAMERIC COLOR MATCHES USING COLOR REPRODUCTION MEDIA

Standard color-matching functions are de signed to represent the mean color-matching response of the population of human observers with norm al color vision. When using these functions, two questions arise. Are they an accurate representation of the population? And what is the unc ertainty in color-match predictions? To address these questions in the dual context of human visual performance and cross-media reproduction , a color-matching experiment was undertaken in which twenty observers made matches between seven different colors presented in reflective a nd transmissive color reproduction media and a CRT display viewed thro ugh an optical apparatus that produced a simple split-field stimulus. In addition, a single observer repeated the experiment 20 times to est imate intra-observer variability. The results were used to evaluate th e accuracy of three sets of color-matching functions, to quantify the magnitude of observer variability, and to compare intra- and inter-obs erver variability in color-matching. These results are compared with v arious techniques designed to predict the range of color mismatches. T he magnitude of observer variability in this experiment also provides a quantitative estimate of the limit of cross-media color reproduction accuracy that need not be exceeded. On average, the differences betwe en matches made by two different observers was approximately 2.5 CIELA B units. (C) 1997 John Wiley & Sons, Inc.