HOW TO: Add Watermarks to Multi-page Documents

RasterSupport.SetLicense(@"C:\LEADTOOLS 19\Common\License\LEADTOOLS.LIC", System.IO.File.ReadAllText(@"C:\LEADTOOLS 19\Common\License\LEADTOOLS.LIC.key"));

string inputFile = @"..\..\Leadtools.pdf";
string watermarkFile = @"..\..\watermark.png";
string outputFile = @"..\..\output.pdf";

using (RasterCodecs codecs = new RasterCodecs())
{
   CodecsImageInfo info = codecs.GetInformation(inputFile, true);
   for (int i = 1; i <= info.TotalPages; i++)
   {
      using (RasterImage image = codecs.Load(inputFile, i))
      {
         // Create AnnBatesStampComposer instance and add the created Bates stamp to it
         using (AnnBatesStampComposer batesStampComposer = new AnnBatesStampComposer())
         {
            //Set the rendering engine
            AnnBatesStampComposer.RenderingEngine = new AnnWinFormsRenderingEngine();
            //Create Bates stamp container
            AnnContainer batesStampContainer = new AnnContainer();
            // Map the resolutions of the AnnContainer to match the image
            batesStampContainer.Mapper.MapResolutions(image.XResolution, image.YResolution, image.XResolution, image.YResolution);
            // Set the size of the AnnContainer based on the size of the image
            batesStampContainer.Size = batesStampContainer.Mapper.SizeToContainerCoordinates(LeadSizeD.Create(image.Width, image.Height));

            // Create AnnBatesStamp and set its properties
            using (AnnBatesStamp batesStamp = new AnnBatesStamp())
            {
               batesStamp.HorizontalAlignment = AnnHorizontalAlignment.Left;
               batesStamp.VerticalAlignment = AnnVerticalAlignment.Top;
               batesStamp.Logo.Opacity = 0.5;
               batesStamp.Logo.Angle = -45;
               batesStamp.Logo.StretchLogo = true;
               batesStamp.Logo.Picture = new AnnPicture(watermarkFile);
               // Add the AnnBatesStamp to the collection
               batesStampComposer.Stamps.Add(batesStamp);
               // Add the AnnContainer to the collection
               batesStampComposer.TargetContainers.Add(batesStampContainer);

               // Render the AnnContainer on the image
               AnnBatesStampComposer.RenderingEngine.RenderOnImage(batesStampContainer, image);
            }
         }
         // Save the resulting RasterImage which contains the newly created watermark
         codecs.Save(image, outputFile, RasterImageFormat.RasPdf, 0, 1, -1, 1, CodecsSavePageMode.Append);
      }
   }
}