Image quality degradation of object-color metamer mismatching in digital camera color reproduction.

Metamer mismatching is a phenomenon where two objects that are colorimetrically indistinguishable under one lighting condition become distinguishable under another one. Due to the unavailability of spectral information, metamer mismatching introduces an inherent uncertainty into cameras' color reproduction. To investigate the degree of image quality degradation by the metamer mismatching, a large spectral reflectance database was compiled in this study to search the object-color metamers sets of the spectra in hyperspectral images. Then, metamer-degraded images were constructed and compared with the ground truth images by directional statistics-based color similarity index image quality assessment metrics to evaluate the perceptual image degradation. The results indicate that the object-color metamer mismatching has only little impact on the image quality degradation, whereas the inappropriate selection of color correction matrices involved with the illumination metamerism is the primary factor for the accuracy decrease in the digital camera color reproduction.