图片加带版权的水印

//// <summary>
    /// 生成带版权水印的图片
    /// </summary>
    /// <param name="IconImg">要生成水印图片的文件地址</param>
    private void MakeWaterMark(string IconImg)
   {
        //定义输出位图
        Bitmap bmp = new Bitmap(640, 480);
        //定义绘图对象
        Graphics g = Graphics.FromImage(bmp);
        //描述绘图矩形区域
        Rectangle newRect = new Rectangle(0, 0, 640, 480);
        //设置背景色
        g.FillRectangle(new SolidBrush(Color.White), newRect);
        //获取要生成水印的图片
        Bitmap newBitmap = new Bitmap(IconImg);
        g.DrawImage(newBitmap, 16, 16);
        //定义水印字的字体
        Font font = new Font(
                               "Arial",
                               12,
                               FontStyle.Bold
                            );
        //定义水印字的格式刷
        LinearGradientBrush brush = new LinearGradientBrush(
                                                              new Rectangle(0, 0, 71, 23),
                                                              Color.Red,
                                                              Color.Blue,
                                                              30f,
                                                              true
                                                           );
        //给照片打上水印
        g.DrawString("copyright by test. " + System.DateTime.Now.ToShortDateString(), font, brush, 0, 0);
        //保存为新的输出图片
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        bmp.Save(ms, ImageFormat.Jpeg);

        //输出图片
        Response.ClearContent();
        Response.ContentType = "image/jpeg";
        Response.BinaryWrite(ms.ToArray());
    }