No 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.

No abstract

Tokyo 163-9 1 , Japan K E Y WORDS. Backscattered electron images, resolution, digital image processing. S U M M A R YIn principle, the resolution of backscattered electron (BSE) images can be little improved, even though an infinitely small beam size is achieved by various improvements in the intrinsic instrument. In order to circumvent this problem, a method is proposed which utilizes an on-line digital computer for the image recording and processing. The major image-processing tools are reduction, expansion, superimposition with matching of the images, and high-emphasis filtering in the Fourier domain. By using various combinations of these techniques, the resolution of BSE images has been significantly improved. The validity of these improved images has been confirmed. In the case of a BSE image with too wide a dynamic range, both the present method and digital homomorphic filtering provide successful results.

No abstract