    T cubic_atXYZ_c(const float fx, const float fy, const float fz, const int c) const {
      return cimg::type<T>::cut(cubic_atXYZ(fx,fy,fz,c));
    }
    T cubic_atXYZ_c(const float fx, const float fy, const float fz, const int c) const {
      return cimg::type<T>::cut(cubic_atXYZ(fx,fy,fz,c));
    }