VARIABLE FOCUSING OF ELECTRON MICROSCOPY IMAGE DATA UTILIZING ORIGIN-CENTERED DISCRETE FRACTIONAL FOURIER TRANSFORM

摘要

Computer-implemented arrangements for adjusting the focus in original electron microscope image data are described. In an implementation, an origin-centered fractional Fourier transform operation and an origin-centered phase restoration operation, both responsive to a provided fractional power value, are collectively applied to original electron microscope image data to produce computationally-focused image data. A parameter adjuster is used to provide a range of variation of the power value, and can be adjusted by a user or under the direction of a control system. The fractional Fourier transform operation and the phase restoration operation can be realized by at least one numerical algorithm and can comprise an approximation.