Incorrect dimension order with HDF5 warp field transforms

[feilong]

Hello,

It seems that loading composite transforms using ITKCompositeH5 may generate incorrect warp fields data. Here is some minimal code and data to replicate the problem:
https://www.dropbox.com/sh/9q7fkiil5acd9wy/AAD9IAK-fPIQZ6HSke67nFPea?dl=0

My understanding is that the tensor dimensions were messed up when the warp field data was loaded from the HDF5 file, somehow the first and the third dimensions were swapped.

ants_t1_to_mniComposite.h5 was from a working directory of fMRIPrep 21.0.2, and it's identical to sub-*_from-T1w_to-MNI152NLin2009cAsym_mode-image_xfm.h5 in the output directory. The NIFTI file was generated using CompositeTransformUtil --disassemble ants_t1_to_mniComposite.h5 ants_t1_to_mniComposite.

Best,
Feilong