Image restoration in sets of noisy electron micrographs

Abstract
The imaging process in a transmission electron microscope (TEM) produces a number of artifacts including the contrast transfer function (CTF) and envelope functions. In addition, when electron cryomicroscopy is performed for purposes of single particle reconstruction, signal to noise ratios are very low, generally peaking between 0.1 and 1.0, and averaging 0.01 to 0.1. We apply a semi-empirical model of the microscope artifacts to optimally correct data used for 3D single particle reconstructions.