Return individual skeletons over the full original image.

[e-koch]

It's not straightforward to return a single filament back into the original image shape. A convenience function of the following would be good to add (fil is a FilFinder2D instance):

from fil_finder.pixel_ident import recombine_skeletons

# For ith filament in fil.filaments
i = 0
mask_i = recombine_skeletons([fil.filaments[i].skeleton()], [fil.array_offsets[i]], fil.image.shape, 0)