Three-dimensional (3D) electron microscopy (3DEM) aims at the determination of the spatial
distribution of the Coulomb potential of macromolecular complexes. The 3D reconstruction
of a macromolecule using single-particle techniques involves thousands of 2D projections.
One of the key parameters required to perform such a 3D reconstruction is the orientation of
each projection image as well as its in-plane orientation. This information is unknown
experimentally and must be determined using image-processing techniques. We propose …