An accelerated expectation-maximization algorithm for multi-reference alignment. (arXiv:2105.07372v2 [eess.SP] UPDATED)

The multi-reference alignment (MRA) problem entails estimating an image from
multiple noisy and rotated copies of itself. If the noise level is low, one can
reconstruct the image by estimating the missing rotations, aligning the images,
and averaging out the noise. While accurate rotation estimation is impossible
if the noise level is high, the rotations can still be approximated, and thus
can provide indispensable information. In particular, learning the
approximation error can be harnessed for efficient image estimation. In this …

algorithm alignment arxiv expectation-maximization reference