This branch enables multi-frame and multi-pixel(scan position) acquisition for current functions: 

1. Whole frame 4D STEM scan with camera running under slave mode or master mode.
2. ROI 4D STEM scan with scan area selected on the acquired HAADF image.
3. 2D HAADF STEM scan without collecting diffraction patterns on the camera.
4. Multi-frame and multi-pixel (scan positions) acquisition for 4D STEM acquisition. 2D HAADF images of a whole scan area is generated by averaged value of repetitions at each scan position.  

Specifications of DE-16 camera:
http://www.directelectron.com/products/de-16/

Publications using this software:
Ultramicroscopy 210 (2020): 112921.  https://doi.org/10.1016/j.ultramic.2019.112921
Acta Materialia 178 (2019): 228-240. https://doi.org/10.1016/j.actamat.2019.08.012

To do list:
1. Save metadata with all the 4D STEM acquisition parameters.
2. Enable time series acquisition with drift correction.