ASSESSING CIE COLOUR RENDERING INDEX UNCERTAINTY USING A RANDOM TEST-COLOUR METHOD

摘要

There are numerous proposals amending the method officially recommended by the International Commission on Illumination (CIE) at present for calculating the colour rendering index in order to define an index of fidelity in the colour reproduction of a light source. Most of these proposals include one or more modifications to the original method, including the colour samples on which the index is calculated, both in reflectance and its distribution on the space of colour and their number. The influence of the number of samples used to calculate the colour rendering index and changes in the index by selecting random samples was studied. The results show that Ra value uncertainty depends on the number of samples and it is directly related to the standard deviation of individual R_(sample) values if the sample set is sufficiently wide.