[Preview of the NLFilter user interface showing noise reduction of a high-resolution micrograph.]

The NLFilter software is developed as a plugin to the commercial software DigitalMicrograph from Gatan Inc for noise reduction of high-resolution transmission electron microscopy (HRTEM) images. The software is based on a developed nonlinear filtering algorithm by a combination of widely used techniques of low-pass filter and Wiener filter. It can efficiently reduce noise without noticeable artifacts even for HRTEM micrographs showing contrast and background variations and HRTEM images of lattice defects. The developed nonlinear filtering algorithm is particularly suitable for quantitative electron microscopy. In addition, NLfilter also works well for noise reduction of 1D spectra. The NLfilter software is written in pure DigitalMicrograph script language, and in principle should run well independent on the DigitalMicrograph version in use.

Users of the NLFiltering plugin are kindly asked to refer to its use

Author: Hongchu Du