From a quick readthrough, it seems that the script creates 2 new images offset_texture and normal_texture.
It does seem to asign data to those images but doesn’t seem to do anything else with them.
perhaps a bpy.ops.image.save_as() command with those textures could get you the output you are looking for?
Oh. Probably i should try to do it, cause after all i find those textures in the project (im doesnt do any texturing work in blender so dont know how to find something related to it).
Normal texture behave normally, i can as example, assing it to object diffuse and save it without problem.
But offset texture behave really wierd.
If i assign offset texture to object, i can see something, some gradients which are good sign, but immidiately after i save those texture to any format - texture becomes black even inside blender.