Skip to main content
. Author manuscript; available in PMC: 2021 Mar 1.
Published in final edited form as: IEEE Signal Process Mag. 2020 Feb 27;37(2):58–76. doi: 10.1109/msp.2019.2957822

Fig. 5:

Fig. 5:

A simulated 3-D structure and a dozen of its noise-free tomographic projections from different viewing directions. The most simplified version of the cryo-EM problem is estimating the 3-D structure from the 2-D projection images when the viewing directions are unknown. In practice, the projections are highly noisy, slightly shifted, and convolved with the microscope’s PSF. Image credit: [71].