The structural model of oxides
In this example, we will cover the extraction of the structural model of a molecule of a bronze-type Niobium oxide, from HAADF-STEM micrographs (further background on this topic can be found in Chapter 5, High-Quality Image Formation by Nonlocal Means Applied to High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy (HAADF--STEM) of the book Modeling Nanoscale Imaging in Electron Microscopy, Vogt T., Dahmen W., and Binev P., Springer Publishing.
The following diagram shows the HAADF-STEM micrograph of a bronze-type Niobium oxide (taken from http://www.microscopy.ethz.ch/BFDF-STEM.htm):

Courtesy: ETH Zurich
For pedagogical purposes, we took the following approach to solving this problem:
- Segmentation of the atoms by thresholding and morphological operations.
- Connected component labeling to extract each single atom for posterior examination.
- Computation of the centers of mass of each label identified as an atom. This presents us with a lattice of...