Application of image processing to STEM tomography of low-contrast materials

Three dimensional analyses of flux pinning centers in Dy-doped YBa2Cu3O7−x coated superconductors by STEM tomography

“…In order to have a better understanding in terms of the structure-property relationship of the material, various image processing methods were applied prior to alignment and reconstruction. A detailed explanation of various image processing methods and their effects on the quality of the tomogram can be found elsewhere [50]. The analyses showed that the image processing techniques that remove the non-uniform illumination (NUI) effect are the most suitable to enhance the contrast and the quality of the tomogram for this specific tilt series.…”

The benefit of thresholding carbon layers in electron tomographic tilt series by intensity downshifting

“…In materials science, an increasing number of methods is now applied during a workflow to improve the quality of a tomographic reconstruction, including the use of: specific acquisition methods such as dual‐axis electron tomography (Tong et al ., ), full rotation specimen holders, focused ion beam milled specimens (Jarausch et al ., ) and impregnation methods (Gontard et al ., ); preprocessing to enhance and discretise image intensities, improve the alignment of a tomographic tilt series or perform sinogram enhancement (Batenburg et al ., ; Ortalan et al ., ; Cao et al ., ; Volkmann ; Bals et al ., ; Roelandts et al ., ; Scott et al ., ; Gontard, ); reconstruction algorithms that are faster and result in fewer missing wedge artefacts (Jinschek et al ., ; Leschner et al ., ; Lange et al ., ; Goris et al ., ; Roelandts et al ., ; Alpers et al ., ; Leary et al ., ; Van den Broek et al ., ); postprocessing of tomograms using approaches such as noise reduction (Frangakis et al ., ; Fernández & Li, ), thresholding, segmentation or automated feature identification (Gommes et al ., ; Batenburg & Sijbers, ; Friedrich et al ., ; Grothausmann et al ., ; Martínez‐Sánchez et al ., ; Lebbink et al ., ; Fernández, ). …”

“…preprocessing to enhance and discretise image intensities, improve the alignment of a tomographic tilt series or perform sinogram enhancement (Batenburg et al ., ; Ortalan et al ., ; Cao et al ., ; Volkmann ; Bals et al ., ; Roelandts et al ., ; Scott et al ., ; Gontard, );…”

“…In materials science, an increasing number of methods is now applied during a workflow to improve the quality of a tomographic reconstruction, including the use of: i. specific acquisition methods such as dual-axis electron tomography (Tong et al, 2006), full rotation specimen holders, focused ion beam milled specimens (Jarausch et al, 2009) and impregnation methods (Gontard et al, 2014); ii. preprocessing to enhance and discretise image intensities, improve the alignment of a tomographic tilt series or perform sinogram enhancement Ortalan et al, 2009;Cao et al, 2010;Volkmann 2010;Bals et al, 2011;Roelandts et al, 2012;Scott et al, 2012;Gontard, 2015); iii. reconstruction algorithms that are faster and result in fewer missing wedge artefacts (Jinschek et al, 2008;Leschner et al, 2010;Lange et al, 2011;Goris et al, 2012;Roelandts et al, 2012;Alpers et al, 2013;Leary et al, 2013;Van den Broek et al, 2014); iv.…”

Removing the effects of the “dark matter” in tomography

“…For certain types of sample geometries, the use of double-tilting, full-rotation holders and adapted preparation methods can be used for decreasing the MW [21,22]. Important progress in ET has resulted from digital processing of tomographic tilt series before 3D reconstruction by accurate interpolation of sinograms, edge detection, contrast enhancement, and accurate alignment of tilt series [23][24][25][26]. The next step is the reconstruction of the tomogram, typically using weighted back-projection (WP) or the simultaneous iterative reconstruction technique (SIRT) [3,24].…”