Correction Method of Color Deviation Caused by Different Angle in Color Measuring

Aiming at the color deviation caused by different angle in color measuring, a correction method has been designed. ${\rm{CIE}}\,x,y$ chromaticity coordinates of 34 RAL-K7 samples under different illumination angles of 30°–60° were measured. Then, we use LASSO function fitting and cross validation to establish a chromaticity coordinate migration prediction model under arbitrary illumination angle in the range of 30°–60°. On this basis, chromaticity coordinates measured under any three illumination angles in the range of 30°–60° can be corrected to the chromaticity coordinate at 45°/0°CIE (Commission Internationale de L'Eclairage) standard illumination observation condition by sequential quadratic programming. The accuracy of the correction method was evaluated by experiments. The research results can provide a correction method of color deviation caused by different angle in color measuring.