    CImg<Tfloat> get_vanvliet(const float sigma, const unsigned int order, const char axis='x',
                              const unsigned int boundary_conditions=1) const {
      return CImg<Tfloat>(*this,false).vanvliet(sigma,order,axis,boundary_conditions);
    }
    CImg<Tfloat> get_vanvliet(const float sigma, const unsigned int order, const char axis='x',
                              const unsigned int boundary_conditions=1) const {
      return CImg<Tfloat>(*this,false).vanvliet(sigma,order,axis,boundary_conditions);
    }