This has been suggested before (by me, and probably others), but it would be quite helpful to have nibabel classes (at least in the nifti hierarchy) support arithmetic and logical operations as syntactic sugar for common operations—at least in cases where the semantics can be defined with little or no ambiguity.

E.g., img1 & img2 would give the logical conjunction of two images; img1 - img2 the difference; etc. It doesn't seem like users are likely to be confused about what these operators do, and obviously they would only work for operands with identical dimensions/affines.