Online-Artikel - Methodenvergleich 3D Scan
Over the recent years, three-dimensional (3D) surface digitization of fossils has achieved wide application in vertebrate paleontology, be it for reconstruction, morphometric or preservation purposes. The wide array of techniques available for 3D surface generation can, however, be somewhat confusing. Therefore, the aim of our study is to help the paleontologist reach a well-informed decision on which technique to use for standard purposes, taking into account aspects such as accuracy, reproducibility, and efficiency. In this study, we are comparing the above aspects when applying micro-computed tomography (micro-CT), manual photogrammetry and automated photogrammetry to an object typically digitized in vertebrate paleontology: a medium-sized fossil mammal cranium (that of an early Oligocene anthracotheriid). Our results show that manual photogrammetry has a high degree of reproducibility and is the most efficient, least costly method of the ones tested, although more training is required for the unexperienced researcher. Also, when attention is paid to proper lighting and overlap, fewer photographs do not necessarily yield inaccurate results, increasing the speed of data acquisition even more. Disadvantages of CT scanning in external surface generation include the lack of a photo surface, and long post-processing times due to removal of internal surface structures that are not used for this purpose. The technology used for automated photogrammetry, MDS Witikon, offers fast and convenient digitization. Large amounts of data and detail produced, however, may be very useful for the creation of object panoramas but exceed the limits for common use of 3D surfaces.