Automated image alignment / stitching for ADF STEM time, focal and camera-length series.
Several types of quantitative ADF experiments start with image-series of some type. This can include time-series, to improve image quality through frame-averaging or to study damage processes, or focal-series to study the optical properties of the microscope of for optical-sectioning experiments.
The first stage in analysing frame-series data is usually to register the set using rigid-registration, this counters translational movement caused by stage or sample drift. After this any scanning distortions caused in the STEM can be corrected using non-rigid registration.
To automatically perform this rigid and non-rigid registration a new software called Smart Align was written. This is compatible with both dark-field and bright-field STEM data, as well as time-series, focal-series or camera-length series.
Uses of the Smart Align rigid / non-rigid registration software include:
- Improving image SNR through frame-averaging without the usual resolution loss from image-blurring,
- Improving image resolution and peak-position accuracy for structural measurements and strain mapping,
- Removing STEM scanning distortions to improve onward analysis such as principle component analysis (PCA).
Smart Align is available to download free of charge for academic / non-commercial use.