How to Create watermarked images in C# ASP.NET ?

//Use NameSpace
using System.Drawing;

//Execute below code at the event, where u wants Water Marking. 
{ 
           // Create a bitmap object of the Image, Here I am taking image from File Control "FileTest" 
            Bitmap bmp = new Bitmap(FileTest.PostedFile.InputStream); 
            Graphics canvas = Graphics.FromImage(bmp); 
            try 
            { 
                Bitmap bmpNew = new Bitmap(bmp.Width, bmp.Height); 
                canvas = Graphics.FromImage(bmpNew); 
                canvas.DrawImage(bmp, new Rectangle(0, 0, 
bmpNew.Width, bmpNew.Height), 0, 0, bmp.Width, bmp.Height, 
GraphicsUnit.Pixel); 
                bmp = bmpNew; 
            } 
            catch(Exception ee) // Catch exceptions 
            { 
                Response.Write(ee.Message); 
            } 
            // Here replace "Text" with your text and you also can assign Font Family, Color, Position Of Text etc. 
            canvas.DrawString("Text", new Font("Verdana", 14, 
FontStyle.Bold), new SolidBrush(Color.Beige), (bmp.Width / 2), 
(bmp.Height / 2)); 
            // Save or display the image where you want. 
            bmp.Save(System.Web.HttpContext.Current.Server.MapPath("~/ 
WaterMarkImages/") + 
FileTest.PostedFile.FileName, 
System.Drawing.Imaging.ImageFormat.Jpeg); 
}