SSIMmap - The structural similarity index measure (SSIM) for maps

The SSIMmap package extend 'the classical SSIM method <https://doi.org/10.1109/TIP.2003.819861> for irregular lattice-based maps and raster images. The SSIMmap package applies this method to two types of maps (polygon and raster). The geographical SSIM method incorporates well-developed 'geographically weighted summary statistics' <https://doi.org/10.1016/S0198-9715(01)00009-6> with an adaptive bandwidth kernel function for irregular lattice-based maps.