Perceived colour differences in displayed colours Part 1: hard copy to soft copy matching

Abstract

An investigation is reported into visual comparisons between object colours and simulations on a cathode ray tube (CRT) monitor display. Experiments are described in which observers viewed a bipartite field in which two coloured areas were separated by a narrow division and viewed against an unlit grey background. One coloured area comprised a surface colour patch illuminated using a light source which was a close colorimetric match to CIE Illuminant D65. The second area was simply an aperture held against the faceplate of the computer CRT monitor, operated with a white point corresponding again to CIE Illuminant D65. The illumination of the reflection patch was arranged so that there was a visual match between a white patch and the monitor white. The monitor patch was controlled in appearance from the keyboard and was specified in terms of red, green and blue pixel values. Observers were asked to match the illuminated reflection patch by adjusting the (unseen) specification of the monitor patch. Separate experiments concerning the ability of observers to detect colour perturbations of matches are also described. Conclusions are drawn as to the concordance of repeated colour matches by individual observers, and between all the observations. The magnitudes of perceptible colour differences are also evaluated.

Keywords:

• colour differences
• CRT monitor
• copy matching