template<typename T> struct Kernel1D {
    std::vector<T> data;
    int mem1, mem2;
    void ProcessImage(std::string filename) {
        // ...
    }
};

template<typename T> Kernel1D<T> Gauss(double, int) {
    Kernel1D<T> ret;
    // fill out ret here
    return ret;
}

int main() {
    Gauss<float>(5.0, 1).ProcessImage("mahdir/mahfilepath.jpg");
    // or
    Kernel1D<float> k = Gauss(5.0, 1);
    k.ProcessImage("mahdir/mahfilepath.jpg");
}