was then segmented into a binary segmentation (of solid & void) using a threshold value. Morphological binary erosion and dilation were required to fill binary 'holes' and remove 'islands' from the binary segmentations. The binary segmentation was used to create a label segmentation where each particle was assigned its own 16bit unsigned integer label. This was achieved using the watershed threshold method from scikit-image on a smoothed distance map . The unsmoothed grey-level and label segmentation were then used as inputs to the GRAPES analysis. Figure shows example segmentations.