Fig. 1. Flowchart of color correction based on non-RAW data

Fig. 2. Nonlinearity correction curves of RGB channels. (a) R channel; (b) G channel; (c) B channel

Fig. 3. Color correction results of Classic card and sample. (a) True color of Classic card; (b) appearance color of sample; (c) JEPG image color of Classic card; (d)-(g) color correction results of Classic card under different methods, which are nonlinearity uncorrected + linear colorimetric characterization model, nonlinearity corrected + linear colorimetric characterization model, nonlinearity uncorrected + polynomial colorimetric characterization model, and nonlinearity corrected + polynomial colori

Fig. 4. Nonlinearity correction curves of RGB channels under three luminance levels. (a) R channel; (b) G channel; (c) B channel

Fig. 5. Chromaticity of light source under different luminance levels

Table 1. Accuracy of colorimetric characterization before and after nonlinearity correction

Table 2. Accuracy of colorimetric characterization before and after nonlinearity correction under three luminance levels

Table 3. Accuracy of colorimetric characterization before and after correction with general nonlinearity correction model under three luminance levels