template<int N, class T>
void filter(T image, double matrix[N][N])
{
    vector<vector<int>> new_img(image->width(), vector<int>(image->height()));
    for (int i = 0; i < image->width(); i++)
    {
        for (int j = 0; j < image->height(); j++)
        {
            double r = 0, g = 0, b = 0;
            for (int k = -N / 2; k <= N / 2; k++)
            {
                for (int l = -N / 2; l <= N / 2; l++)
                {
                    int x = i + k, y = j + l;
                    if (x < 0)
                        x *= -1;
                    if (x >= image->width())
                        x = image->width() - (x - image->width());
                    if (y < 0)
                        y *= -1;
                    if (y >= image->height())
                        y = image->height() - (y - image->height());
                    auto c = image->pixel(x, y);
                    r += qRed(c) * matrix[k + N / 2][l + N / 2];
                    g += qGreen(c) * matrix[k + N / 2][l + N / 2];
                    b += qBlue(c) * matrix[k + N / 2][l + N / 2];
                }
            }
            new_img[i][j] = qRgb(r, g, b);
        }
    }
    for (int i = 0; i < image->width(); i++)
    {
        for (int j = 0; j < image->height(); j++)
        {
            image->setPixel(i, j, new_img[i][j]);
        }
    }
}

void MainWindow::button2_slot() {
    if (!image) return;
    system("echo \"start\"");
    const int N = 5;
    double matrix[N][N] =
    {
        {1, 1, 1, 1, 1},
        {1, 1, 1, 1, 1},
        {1, 1, 1, 1, 1},
        {1, 1, 1, 1, 1},
        {1, 1, 1, 1, 1}
    };
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            matrix[i][j] /= N * N;
        }
    }
    filter<N>(image, matrix);
    system("echo \"end\"");
    update_image();
}