An algorithm for processing a diffractogram of an electron image input by an on-line system has been improved, with the aid of projection theory, so as to achieve real time operation. This algorithm can, therefore, automatically focus in scanning electron microscope, and correct for the astigmatic aberration of both transmission and scanning electron microscopes by analyzing the spectrum computed from the diffractogram. Experimental results show that this algorithm is effective for detecting the amount of defocus and astigmatism in both transmission and scanning electron microscopes.
Baba, Norio; Oho, Eisaku; and Kanaya, Koichi
"An Algorithm for On-Line Digital Image Processing for Assisting Automatic Focusing and Astigmatism Correction in Electron Microscopy,"
Scanning Microscopy: Vol. 1
, Article 4.
Available at: https://digitalcommons.usu.edu/microscopy/vol1/iss4/4