2019/01/31 by R. Patrick Xian, Rui Patrick Xian, Laurenz Rettig +1 · 23 citations
Biochemistry, Genetics and Molecular Biology · Materials Science · Mathematics · Physics and Astronomy · #Advanced Electron Microscopy Techniques and Applications #Algorithm #Bandwidth (computing) #Computational physics #Computer science #Distortion (music) #Electron and X-Ray Spectroscopy Techniques #Geometry #Mathematical analysis #Mathematics #Nuclear Physics and Applications #Physics #Rotational symmetry #Symmetrization #Symmetry (geometry) #physics.data-an
paper · pdf · doi:10.1016/j.ultramic.2019.04.004
published in Ultramicroscopy 202, 133-139 (Elsevier BV)
arxiv created 2019/04/07 · openalex publication_date 2019/04/15 · arxiv updated 2020/05/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Image symmetrization is an effective strategy to correct symmetry distortion in experimental data for which symmetry is essential in the subsequent analysis. In the process, a coordinate transform, the symmetrization transform, is required to undo the distortion. The transform may be determined by image registration (i.e. alignment) with symmetry constraints imposed in the registration target and in the iterative parameter tuning, which we call symmetry-guided registration. An example use case of image symmetrization is found in electronic band structure mapping by multidimensional photoemission spectroscopy, which employs a 3D time-of-flight detector to measure electrons sorted into the momentum (kx, ky) and energy (E) coordinates. In reality, imperfect instrument design, sample geometry and experimental settings cause distortion of the photoelectron trajectories and, therefore, the symmetry in the measured band structure, which hinders the full understanding and use of the volumetric datasets. We demonstrate that symmetry-guided registration can correct the symmetry distortion in the momentum-resolved photoemission patterns. Using proposed symmetry metrics, we show quantitatively that the iterative approach to symmetrization outperforms its non-iterative counterpart in the restored symmetry of the outcome while preserving the average shape of the photoemission pattern. Our approach is generalizable to distortion corrections in different types of symmetries and should also find applications in other experimental methods that produce images with similar features.