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		<title>WikiSysop: Created page with &quot;== Citation ==  Ma, C., Bendory, T., Boumal, N., Sigworth, F. and Singer, A. 2020. Heterogeneous multireference alignment for images with application to 2D classification in single particle reconstruction. IEEE Transactions on Image Processing. 29, (2020), 1699–1710.  == Abstract ==  Motivated by the task of 2D classification in single particle reconstruction by cryo-electron microscopy (cryo-EM), we consider the problem of heterogeneous multireference alignment of ima...&quot;</title>
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		<summary type="html">&lt;p&gt;Created page with &amp;quot;== Citation ==  Ma, C., Bendory, T., Boumal, N., Sigworth, F. and Singer, A. 2020. Heterogeneous multireference alignment for images with application to 2D classification in single particle reconstruction. IEEE Transactions on Image Processing. 29, (2020), 1699–1710.  == Abstract ==  Motivated by the task of 2D classification in single particle reconstruction by cryo-electron microscopy (cryo-EM), we consider the problem of heterogeneous multireference alignment of ima...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;== Citation ==&lt;br /&gt;
&lt;br /&gt;
Ma, C., Bendory, T., Boumal, N., Sigworth, F. and Singer, A. 2020. Heterogeneous multireference alignment for images with application to 2D classification in single particle reconstruction. IEEE Transactions on Image Processing. 29, (2020), 1699–1710.&lt;br /&gt;
&lt;br /&gt;
== Abstract ==&lt;br /&gt;
&lt;br /&gt;
Motivated by the task of 2D classification in single&lt;br /&gt;
particle reconstruction by cryo-electron microscopy (cryo-EM),&lt;br /&gt;
we consider the problem of heterogeneous multireference alignment&lt;br /&gt;
of images. In this problem, the goal is to estimate a (typically&lt;br /&gt;
small) set of target images from a (typically large) collection&lt;br /&gt;
of observations. Each observation is a rotated, noisy version&lt;br /&gt;
of one of the target images. For each individual observation,&lt;br /&gt;
neither the rotation nor which target image has been rotated are&lt;br /&gt;
known. As the noise level in cryo-EM data is high, clustering the&lt;br /&gt;
observations and estimating individual rotations is challenging.&lt;br /&gt;
We propose a framework to estimate the target images directly&lt;br /&gt;
from the observations, completely bypassing the need to cluster&lt;br /&gt;
or register the images. The framework consists of two steps.&lt;br /&gt;
First, we estimate rotation-invariant features of the images, such&lt;br /&gt;
as the bispectrum. These features can be estimated to any&lt;br /&gt;
desired accuracy, at any noise level, provided sufficiently many&lt;br /&gt;
observations are collected. Then, we estimate the images from the&lt;br /&gt;
invariant features. Numerical experiments on synthetic cryo-EM&lt;br /&gt;
datasets demonstrate the effectiveness of the method. Ultimately,&lt;br /&gt;
we outline future developments required to apply this method to&lt;br /&gt;
experimental data.&lt;br /&gt;
&lt;br /&gt;
== Keywords ==&lt;br /&gt;
&lt;br /&gt;
== Links ==&lt;br /&gt;
&lt;br /&gt;
https://ieeexplore.ieee.org/abstract/document/8864095/&lt;br /&gt;
&lt;br /&gt;
== Related software ==&lt;br /&gt;
&lt;br /&gt;
== Related methods ==&lt;br /&gt;
&lt;br /&gt;
== Comments ==&lt;/div&gt;</summary>
		<author><name>WikiSysop</name></author>
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