Effects of the Downsampling Scheme on Three-dimensional Electron Microscopy of Single Particles

Electron microscopy of single particles aims at the elucidation of the three-dimensional structure of macromolecular complexes. This information is crucial for the more complete understanding of how these nanomachines perform their functions in the cell. Electron microscopy images are recorded in digital form at a resolution much higher than needed from the signal theory point of view. Then, they are downsampled to the required resolution. The electron microscopy community has paid little attention to this step assuming that even a trivial filter, as "bining", does not affect the posterior image processing steps. In this paper we show that this hypothesis is not correct.