A method is provided for determining the position of a first structure (8a) relative to a second structure (8b) or a part thereof, said method having the steps of: a) providing a first picture (F1) having a multiplicity of pixels and which contains the first structure, b) providing a second picture (F2) having a multiplicity of pixels and which contains the second structure, c) forming an optimization function with the displacement of the two pictures relative to one another as parameter, the optimization function overlying the two pictures and masking the overlay such that in a determination of an extreme value of the optimization function a contribution is made only by the region of the overlay that corresponds to the second structure or the part thereof, d) ascertaining the extreme value of the optimization function and determining the optimal value of the displacement based on the extreme value of the optimization function, and e) determining the position of the first structure relative to the second structure or a part thereof with the optimal displacement value ascertained in step d).