Computes a structural similarity metric (after the style of
MS-SSIM for images) for binary and categorical 2D and 3D images. Can be
based on accuracy (simple matching), Cohen's kappa, Rand index, adjusted
Rand index, Jaccard index, Dice index, normalized mutual information, or
adjusted mutual information. In addition, has fast computation
of Cohen's kappa, the Rand indices, and the two mutual informations.
Implements the methods of Thompson and Maitra (2020)