Ab-initio contrast estimation and denoising of cryo-EM images.

ABSTRACT:

Background and objective

The contrast of cryo-EM images varies from one to another, primarily due to the uneven thickness of the ice layer. This contrast variation can affect the quality of 2-D class averaging, 3-D ab-initio modeling, and 3-D heterogeneity analysis. Contrast estimation is currently performed during 3-D iterative refinement. As a result, the estimates are not available at the earlier computational stages of class averaging and ab-initio modeling. This paper aims to solve the contrast estimation problem directly from the picked particle images in the ab-initio stage, without estimating the 3-D volume, image rotations, or class averages.

Methods

The key observation underlying our analysis is that the 2-D covariance matrix of the raw images is related to the cov

SUBMITTER: Shi Y 

PROVIDER: S-EPMC9392052 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature