Minimal MINC 2.0 File

Of all of the variables, dimensions, and attributes described here, only the ``image'' variable and its associated dimensions are required to define a valid MINC file.

However, all MINC 2.0 files should contain at least an empty group framework consisting of the minc-2.0 group and the three principal subgroups image, info, and dimensions.

Any missing attributes are assumed to have default values, or to be undefined.