Image image = new Bitmap(200, 200);
                    Image secimage = new Bitmap(400, 400);
                    using (Graphics gr = Graphics.FromImage(secimage))
                    {
                        gr.InterpolationMode = InterpolationMode.Low;
                        gr.DrawImage(
                          image,
                          new Rectangle(0,0,400,400),
                          0, 0,
                          image.Width, image.Height,
                          GraphicsUnit.Pixel
                          );
                    }