Accessing header transformations

[Lestropie]

Verification of some types of metadata necessitates knowledge of the header transform of a corresponding image. Image formats under evaluation are not just NIfTI, but also MRtrix formats.

Currently, the transformation is accessed using mrinfo <imagepath> -transform -config RealignTransform false. While I can be reasonably confident that this will be faithful to whatever is stored on disk for all supported formats, there is nevertheless always a risk in using a piece of software to verify its own operation. I've had multiple instances where I've ensured that I can export to some format and then load it again, only to discover that there was some problem with the intermediate data if interpreted by some other tool.

Perhaps the ideal solution would be to use nibabel. However AFAIK support for MRtrix image formats is still not present there. fslhd only supports NIfTI so does not cover all use cases.