Comparison between the integral EW and the fitted EW of the DIBs λ15780, λ5797, and λ16614 for their HQ samples, from the subfigures (a) to (c). For each subfigure, the upper panel shows the Gaussian KDE number density plot of the integral EW as a function of the fitted EW, with the red dashed line representing the one-to-one relation. The lower panel displays the Gaussian KDE number density plot of the difference between the integral EW and the fitted EW, namely ∆EW = EW_int − EW_fit as a function of the fitted EW, with the green dashed line representing the zero benchmark. The distribution of ∆EW is also overplotted in the upper panel with its mean and standard deviation annotated.