Colour Appearance Modelling

At TAGA 1989 a paper was presented discussing the preliminary findings of an experiment to evaluate models for colour appearance. Since that time we have completed the data analysis and confirmed that both Hunt and Nayatani models do not perform particularly well, principally with respect to lightness predictions. The Hunt model has been modified in the light of these findings and a significant improvement in prediction is demonstrable. The revised model is now believed to be a good predictor of appearance and is being used to produce colour matches between colour monitor and print for five different conditions of viewing. Those viewing conditions consist of four levels of chromatic adaptation, one of which (D5000) has white and black borders around the page. The matching has necessitated converting tristimulus data to CMY dot area or density for a variety of output devices. The problems of achieving this will be reviewed and techniques used in this project described. The matching has necessitated converting tristimulus data to CMY dot area or density for a variety of output devices. The problems of achieving this will be reviewed and techniques used in this project described. A new program of work has been initiated to follow on from this initial study which will extend the range of viewing conditions to include transparency samples and expand on the range of illumination levels. The work proposed for this extension will be briefly reviewed.