Fig. 6

Examples of sagittal reconstructions of CT acquisitions of sediment cores, which were annotated with a digital ruler (not shown) and used during geological sampling to identify and locate coral fragments below the surface. a Before alignment correction. b After alignment correction. c Difference image before/after alignment correction. Areas with high density before correction and low density after correction are shown in white, areas with low density before correction and high density after correction are shown in black. Note the large differences in sample position in-plane and the smaller differences out-of-plane. For the effect of alignment correction on the sampling process, consider the coral fragment indicated by the arrow. As can be observed from the difference image, trying to sample this fragment at the location indicated by the uncorrected image would completely miss the fragment