QFocus

QFocus is an interactive program for structure projection reconstruction from through-focus series of high-resolution transmission electron microscopy (HRTEM) images taken with fixed focus steps. It is based on the contrast transfer function (CTF) theory for thin crystals. Aberration parameters such as defocus values and two-fold astigmatisms of the image series are determined using figure of phase similarity of reflections after applying CTF correction with test defocus values. CTF correction is applied to all images in the series and CTF-corrected images are combined to obtain a structure image. The program has a user-friendly graphical user interface and supports DigitalMicrograph (DM3), MRC and many other common image formats. The program runs on Windows.