(a) A BF TEM image of a 50-nm-thick Pt film at 800°C during an in situ heating experiment. (b) A BF TEM image of a 30-nm-thick Pd film at 400°C during an in situ heating experiment. (c,d) Images from a and b with grain boundary segmentations overlaid, generated from three diffraction conditions for Pt and one diffraction condition for Pd. They were generated using the same model weights as the Al data, and the postprocessing was optimized in the same way as the Al data, based on one machine-assisted hand tracing for each material.