Open AccessA STUDY ON IMAGE QUALITY DEPENDING ON DEFOCUSING HREM WITH IMAGE QUALIFICATION THEORY OF LINFOOT
Author(s) -
Xiao-Qing Shen
Publication year - 1989
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.38.516
Subject(s) - optics , materials science , quality (philosophy) , image (mathematics) , crystal (programming language) , foil method , electron microscope , icosahedral symmetry , similarity (geometry) , phase (matter) , image quality , amorphous solid , character (mathematics) , physics , computer science , chemistry , quantum mechanics , mathematics , computer vision , geometry , crystallography , composite material , programming language
Using image qualification theory of Linfoot, we studied the deforcusing character of imaging of weak phase object in HREM. The power spectrum of electron micrographs of an amorphous carbon thin foil specimen of 10 μm thick is measured from which the distribution of the relative structral content is determined. It is further verified by numerical analysis. The correlation factor, the image fidelity, the choice of the defocus amount in the electron microscope for the unkown crystal objects and automatic focusing is discussed.