J. Andén, E. Katsevich, A. Singer, ``Covariance estimation using conjugate gradient for 3D classification in Cryo-EM”, 12th IEEE International Symposium on Biomedical Imaging (ISBI 2015) arXiv
Extension of the previous method of Katsevich, Katsevich, and Singer for estimating the 3D covariance matrix of a heterogeneous population of volumes. The method is based on conjugate gradient for solving a sparse linear system, and allows for incorporation of contrast transfer function and non-uniform distribution of viewing angles, making it more suitable for real-world data. Performance is evaluated on a synthetic dataset and on an experimental dataset obtained by imaging a 70S ribosome complex.
Heterogeneity, 3D covariance, conjugate gradient