I have a few MNI labels, and I need to identify the centroid of the volume in MNI coordinate space. These are binary files in compressed nifti format. At first, i thought could use mri_volcluster, and simply set the minimum to 0.01, which would capture the remaining voxels and then compute a centroid. However, this seems not to be the case. The coordinates refer only to the edge of the volume which is not correct.