To evaluate whether the above image metrics predict time-of-day ratings, we performed correlations (visualized in
Figure A1) and found that all 30 image statistics were significantly correlated with mean time-of-day scores (
p < 0.0001 for all). We report correlations where the absolute value of
r is greater than 0.6, namely, positive correlations for luminance skewness (
r = 0.82) and saturation−luminance correlation (
r = 0.62), as well as negative correlations for mean image luminance (
r = −0.81), mean image luma (
r = −0.81), mean melanopsin input (
r = −0.78), mean L-cone input (
r = −0.82), mean M-cone input (
r = −0.81), mean S-cone input (
r = −0.73), mean rod input (
r = −0.79), RMS luminance contrast (
r = −0.81), RMS contrast (B channel) (
r = −0.71), b* standard deviation (
r = −0.72), ∆E00 (
r = −0.67), mean luminance-weighted CCT (
r = −0.69), b*-luminance image distance (
r = −0.72), saturation−luminance image distance (
r = −0.69), and chroma−luminance image distance (
r = −0.73).