The effect of color sample numbers recommended by CIE on general color rendering index calculation

The different parametric descriptors are introduced for surface appearance measurement. Color rendering is a color scalar to show the effect of an illuminant on the color appearance of objects by comparison with its color appearance under a reference illuminant. The spectral qualities of the light source, the object being illuminated and the visual physiology affect the color rendering calculations. The 15 color samples are recommend by CIE for calculating the general color rendering index. At the present work, the general color rendering index (CRI) two CIE illuminants F2 and F11 were calculated based on two groups consisting 8 (group I) and 15 (group II) samples when illuminated by a reference illuminant. The results were not the same. The obtained results for CRI based on group I and II change from 64 to 52 for illuminant F2 and 85 to 76 for illuminants F11. The color inconstancy index CMCCON02 for the samples was proposed as a criteria for optimal selection of samples. The samples with higher color constancy could be selected for the desirable color rendering results.