  We investigate the influence of periodic surface roughness in thin
ferromagnetic films on shape anisotropy and magnetization behavior inside the
ferromagnet. Starting from the full micromagnetic energy and using methods of
homogenization and $\Gamma$-convergence we derive a two dimensional local
reduced model. Investigation of this model provides an insight on the formation
mechanism of {\it perpendicular magnetic anisotropy} and uniaxial anisotropy
with an {\it arbitrary} preferred direction of magnetization.
