Pattern-recognition image processing of 3D atom-probe data
The ultimate three-dimensional atom probe (3DAP) system would have sufficient spatial resolution so that the crystal structure of a material could be determined directly from the atomic positions. Aberrations in the trajectories of ions evaporated from the specimen are the primary limitation on the lateral resolution of AP analysis. In the near future, it does not seem likely that these aberrationsmay be corrected physically because there is no theoretical description and there has been very little empirical work. If the lattice is known a priori, a suggestion was proposed to force the atoms to their nearest lattice sites. This work reports progress that has been made using Fourier transform (FT) and pattern recognition techniques to reconstruct an original lattice structure from simulated 3DAPdata and subsequently to force atoms to pick their nearest lattice point. Usually FT techniques areused in image processing to reduce the image noise, not actually to shift features in the image.