The first step was to crop the tomograms to include the region-of-interest only, in this case the electrode tab. Next, we registered the tomograms onto each other. This ensured that the same co-ordinates in each tomogram represented the same points in real space. Registration was performed using SimpleITK. The registered tomograms were then converted to 8-bit, smoothed using a non-local means filter, and then segmented into binary images (particles/background) using a threshold. Morphological binary erosion and dilation was used to remove small binary 'islands' and 'holes' from the segmentation.