  We define morphological operators and filters for directional images whose
pixel values are unit vectors. This requires an ordering relation for unit
vectors which is obtained by using depth functions. They provide a
centre-outward ordering with respect to a specified centre vector. We apply our
operators on synthetic directional images and compare them with classical
morphological operators for grey-scale images. As application examples, we
enhance the fault region in a compressed glass foam and segment misaligned
fibre regions of glass fibre reinforced polymers.
