Dave Mitchell's DigitalMicrograph™ Scripting Website

Function

Reduces the horizontal banding found in images acquired on cold FEG systems, due to stochastic changes in emission.

Version

version:20201029, v3.0

Author

D. R. G. Mitchell

Acknowledgements

Thanks to William Costello for suggesting and testing this script.

Comments

This script creates a vertically averaged image and divides it back into the original, markedly reducing the appearance of FEG-induced horizontal bands.

System Requirements

Should be compatible with all recent versions of DigitalMicrograph.

Known Issues

Horizontal features in the image, such as scale bars (those burnt into the image, not floating ones found in .dm4 images) will cause artefacts.

The previous version (v2.0) worked well on images with relatively uniform contrast. However, where large variations in contrast were present, such as those due to coarse particles etc, then such features would introduce banding of their own. In this version a rectangular region of interest (ROI) can be used to define a region in the image in which there is uniform contrast from top to bottom. This might be an area of carbon support adjacent to a coarse particle. The ROI need only define the width of the region to be used, as the script will automatically extend the ROI to the top and bottom of the image. The ROI should be as wide as possible, consistent with avoiding regions of high contrast variation, in order to ensure good averaging. If no ROI is present, then, as before, averaging across the whole image will be carried out.

Supported

Yes

Included Files

Main script file.

Source Code