Open AccessNoise reduction in high‐magnification micrographs by soft focus printing and digital image processing
Author(s) -
Peters KlausRuediger
Publication year - 1985
Publication title -
scanning
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.359
H-Index - 47
eISSN - 1932-8745
pISSN - 0161-0457
DOI - 10.1002/sca.4950070405
Subject(s) - micrograph , magnification , opacity , materials science , focus (optics) , optics , noise (video) , image processing , electron micrographs , moiré pattern , noise reduction , computer vision , artificial intelligence , computer science , scanning electron microscope , image (mathematics) , electron microscope , physics
Soft focus printing of micrographs, using screens of opaque material with 10–15 lines/cm, reduced contrast due to noise but preserved all other contrasts and all structural details. Appropriate screens generated diffraction fringes of a spacing similar to the distance of the noise structures. The superimposition of fringes and image produced a diffusion effect which reduced only the contrast of the noise background. Blurring, screening or fogging were not effective or suitable for photographic micrograph processing. Soft focus printing improved recognition of weak high magnification contrasts in SEM micrographs of uncoated, gold decorated, and chromium coated cell surfaces of glomerular endothelium in mouse kidney slices. Effects similar to the optical diffusion were obtained by digital image processing using weighted low pass filters.