Visualization and prediction of porosity in roller compacted ribbons with near-infrared chemical imaging (NIR-CI).

•The relatively fast oil absorption method was comparable with the more tedious mercury intrusion method (R2=0.98).•It was confirmed by both reference methods that ribbons compressed at a higher pressure resulted in a lower porosity.•Using NIR-CI and multivariate data analysis it was possible to visualize and predict the porosity distribution of the ribbons.•Heterogeneous porosity areas were seen for roller compacted ribbons.