A virtual imaging system for colour research

A visualization system has been constructed to provide an accurate representation of a group of surface colours under a range of different light sources. The impetus for this work has come from the burgeoning supply of new high-output LED (light-emitting diode) sources now entering the market. The system will be used to test the validity of the CIE (International Commission on Illumination) colour rendering index (CRI) for these and other sources. The system computes and displays each colour from a knowledge of the light-source spectrum and the spectral reflectance of each surface, and can simultaneously display the resultant colours from two different sources as well as computing the colour differences for the two sets of colours. Subjective tests are being undertaken to validate the computed results.