FFT_of_Stack.ijm

setBatchMode(true);
id = getImageID();
n = nSlices();
for(i=1; i<=n; i++) {
  setSlice(i);
  run("FFT");
  run("Select All");
  run("Copy");
  run("Close");
  if (!isOpen("Stack of FFT"+id)) {
    run("Internal Clipboard");
    rename("Stack of FFT"+id);
  } else {
    selectImage("Stack of FFT"+id);
    run("Add Slice");
    run("Paste");
  }
  selectImage(id);
}
selectImage("Stack of FFT"+id);
setBatchMode(false);