A new non-linear pseudo-Laplacian filter for enhancement of secondary electron images

Abstract

SUMMARY A simple, yet effective, non-linear pseudo-Laplacian filter has been newly developed to enhance secondary electron (SE) images. This filter is a combination of the second derivative along the direction of the local gradient and a non-linear weight factor. The filter can successfully enhance SE images without the undesirable effects of noise which are often seen in conventional Laplacian filtered images. Hence, the processed results with high image quality can make original SE images easier to interpret. The effectiveness is especially useful in low-voltage scanning electron microscopy, because SE images taken at low voltages are not so likely to have good image sharpness.