Drift corrected EFTEM Imaging

Category: Microscope & GIF
Author:
Description: This script offers an automatic and modified acquisiton methode for EFTEM imaging. Conventional acquired EFTEM images with exposure times above one minute tend to be blurry because of the specimen spatial drift. To alleviate the blurring of the images caused by the drift, this script takes several EFTEM images with a shorter exposure time (sub-images) and merges these sub-images afterwards. To correct for the spatial drift between these sub-images, elastically filtered images are acquired between two subsequent sub-images. These elastically filtered images are used for spatial drift correction based on the cross-correlation method. The gathered drift information between two elastically filtered images is used to drift-corrected the sub-images automatically and merge them afterwards. An increased field of view can be achieved by using the Image Shift function of the microscope for active drift correction during the measurement. Artifacts that are caused by prominent noise-peaks in the dark reference image are suppressed by calculating the dark reference image from three images. Furthermore, it is possible to drift-correct a set of EFTEM images already during the acquisition to simplify the post-processing for elemental mapping. known issues: Because the DM commands for the change of the energy-loss differ between different versions the script might prompt an error when started. For this case the other known commands are available in the respective sub-routines as comments.
Comments: This script is written for and tested with a ZEISS Libra 200 FE TEM. Some of the commands are specific for this type of TEM and must be replaced by the respective commands of the own microscope. These command are: see below
Acknowledgements: This script is related to the publication: T. Heil, H. Kohl, Optimization of EFTEM image acquisition by using elastically filtered images for drift correction, Ultramicroscopy 110 (2010) 748-753 Please add this publication to the Publications and scripting references. comments & known issues
Script version: 2.0
DM/GMS version: 1.82
Hardware: ZEISS Libra 200 FE TEM
Script written as a function: No
Source: Show code
Download Source Code: Download
Download Zip File: Download