The following ImageJ macro code should print the directory for an open image:-

imageName = getTitle();
dir = getDirectory("image");
print(dir);

This fails using Fiji, which recently prompted me to use SCIFIO for all image I/O if I am not mistaken. When I use vanilla ImageJ it works fine, and if I un-tick,
  Edit->Options->Use SCIFIO when opening image files
it also works fine.

Apologies if I have not categorised this bug correctly (could not see a SCIFIO category), or if I should've reported it elsewhere. I suspect it does mean a lot of macros are likely to fail using Fiji with default options though.

Graeme

PS. screenshot attached