Dear freesurfers,

I'm new to freesurfer and have a problem using --apply_inverse_transform with the .m3z warp. Any help would be greatly appreciated:

I've been running a multivariate fmri decoding study, and have used freesurfer to generate anatomical masks which I've used as ROIs for the multivariate analysis in the native space of each subject. I then took the pattern of informative voxels from each subject as a binary mask, and warped it into standard space using the freesurfer high-dimensional warp (I am looking at subcortical structures, so this level of registration accuracy is quite important) with the following command:

mri_convert -ot nifti1 ~/inputimage --apply_transform ~/transforms/talairach.m3z ~/outputimage.img

Which seems to have worked fine. I've then performed some overlap analyses on these warped binary images, and created a new binary image representing the between-subject overlap. What I really want to do next is to warp this back into the native space for each subject and use as an ROI for further multivariate analyses. To do this I tried the following command:

mri_convert -it nifti1 -ot nifti1 ~/inputimage.img --apply_inverse_transform ~/transforms/talairach/m3z ~/outputimage.img

which gave me the following error message:

mriBuildVoronoiDiagramFloat: incorrect input type(s)

Any ideas on what I'm doing wrong here?

Many thanks,

Martin