You can use flirt -applyisoxfm for this. I don't know if spline interpolation is in the 4.1.9 version of FLIRT, but it doesn't seem to work with -applyisoxfm. Peace, Matt. _____ From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf Of David Grayson Sent: Monday, December 19, 2011 9:16 PM To: [log in to unmask] Subject: [FSL] resample image data Hi FSL users, I am wondering how to resample an image by any arbitrary factor, and keep the same centering? fslmaths -subsamp2 only allows for a factor of 2. For instance, I'd like to resample my high-res atlas image from 1x1x1 mm to 3x3x3 mm, so that when I register my filtered_func_data to my atlas, I can use my atlas_333 image as reference, and my func data will be aligned and in 333 space. Thanks very much for any insight, David