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. CIE x, y chromaticity coordinates of 34 RAL-K7 samples under different illumination angles of 30 degrees-60 degrees 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 degrees-60 degrees. On this basis, chromaticity coordinates measured under any three illumination angles in the range of 30 degrees-60 degrees can be corrected to the chromaticity coordinate at 45 degrees/0 degrees 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.