cv::Mat align_mean(cv::Mat mean, cv::Rect facebox, float scaling_x=1.0f, float scaling_y=1.0f, float translation_x=0.0f, float translation_y=0.0f)

{

    using cv::Mat;

    // Initial estimate x_0: Center the mean face at the [-0.5, 0.5] x [-0.5, 0.5] square (assuming the face-box is that square)

    // More precise: Take the mean as it is (assume it is in a space [-0.5, 0.5] x [-0.5, 0.5]), and just place it in the face-box as

    // if the box is [-0.5, 0.5] x [-0.5, 0.5]. (i.e. the mean coordinates get upscaled)

    Mat aligned_mean = mean.clone();

    Mat aligned_mean_x = aligned_mean.colRange(, aligned_mean.cols / );

    Mat aligned_mean_y = aligned_mean.colRange(aligned_mean.cols / , aligned_mean.cols);

    aligned_mean_x = (aligned_mean_x*scaling_x + 0.5f + translation_x) * facebox.width + facebox.x;

    aligned_mean_y = (aligned_mean_y*scaling_y + 0.3f + translation_y) * facebox.height + facebox.y;

    return aligned_mean;

}