afni.nimh.nih.gov

Hi Xiyue,

That is simply because of the the larger box of the result.
161x191x151 / (100*100*80) ~= 5.8, and 610 * 5.8 = 3538.

I don't think that @auto_tlrc has any ability to specify a master output grid. But it would be possible to extract the warp and apply it with 3dAllineate instead, which does have a -master option for the output grid.

Are the voxels really 1mm isotropic? What was the original voxel size?

- rick