Hi Bedda - You need to specify the action in addition to the kernel. e.g. -kernel boxv 3 -dilM Cheers Eugene On 13 October 2015 at 19:16, Bedda Rosario <[log in to unmask]> wrote: > Hello, > > I would like to dilate around each non zero voxel. How can I do this? > > I tried fslmaths inputimage -kernel boxv 3 outputimage, but nothing > happens. > > Any help is appreciate it. > > Thank you, > Bedda >