The aim of the present work is to analyze the performance for color measurements of systems based on optoelectronic imaging sensors, training the imaging system by measuring color patches belonging to widely different color gamuts, and optimizing the capture conditions with a luminance adaptation model so that all the digital signals were located within the linear range of the system response. The application of this luminance adaptation model allows to measure all the colors in a common scene which could contain colors very different in luminance, and as a result, the dynamic range of the system to be increased.The employed imaging system was composed of a 12 bitdepth CCD monochrome camera attached to an objective lens. Two different configurations were used: a colorimetric one, with three acquisition channels obtained by means of an RGB tunable filter, and a multispectral one, with seven acquisition channels obtained by placing a motorized wheel with seven interference filters.The quality of the color measurements provided by each configuration was analyzed in terms of the mean, maximum and minimum CIELab color differences between the predicted XYZ tristimulus values, and the measured XYZ ones. The distribution of the color difference values of the patches for each color chart was also considered by means of histograms of color differences.The results obtained showed that it is possible to increase the color gamut without a loss of performance. Similar results were obtained using the CCDC chart, the selected Munsell colors, and these both joined as training and test sets, which indicated that either the selected Munsell colors or the CCDC allowed to train the system properly. A slight improvement in the results was observed using the multispectral configuration with respect to the colorimetric one when the same set of colors was used as training and test set.
Jaume Pujol, Marta de Lasarte, Meritxell Vilaseca, Montserrat Arjona, "High Dynamic Range Multispectral System for Wide Color Gamut Measurements" in Proc. IS&T CGIV 2006 3rd European Conf. on Colour in Graphics, Imaging, and Vision, 2006, pp 404 - 409, https://doi.org/10.2352/CGIV.2006.3.1.art00083