Fig. 6.

Comparison of our algorithm (MRA) with EM in terms of relative estimation error and computation time. Images are generated from 5 classes with uniformly random in-plane rotations. Contrary to MRA, EM needs to assume the rotations are selected from a discrete set. Here, we see the accuracy/computation time trade-off of EM for $\text{SNR}=1/50$. Left panel: for each discretization value (i.e., number of uniformly sampled angles) and algorithm, each point represents the relative estimation error compared to groundtruth images after sPCA for one of the classes. Right panel: integers indicate the number of EM iterations. The CPU time is measured in seconds.