[] HOW TO: Split content of one PDF page to separate files

void ExtractDocumentText(string _documentFile)
{
   using (LEADDocument _document = DocumentFactory.LoadFromFile(_documentFile, new LoadDocumentOptions()))
   {
      IOcrEngine _ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD);
      _ocrEngine.Startup(null, null, null, @"C:\LEADTOOLS22\Bin\Common\OcrLEADRuntime");
      _document.Text.OcrEngine = _ocrEngine;

      foreach (DocumentPage _page in _document.Pages)
      {
         DocumentPageText _pageText = _page.GetText();
         _pageText.BuildWords();
         RasterCodecs infoCodecs = new RasterCodecs();
         int pageNumber = 1 + _document.Pages.IndexOf(_page); //pages are 1-based
         CodecsImageInfo pageInfo = infoCodecs.GetInformation(_documentFile, false, pageNumber);
         // we'll use 300 dpi
         double sizeAt300 = pageInfo.Height * 300.0 / pageInfo.YResolution;
         double sizeFactor = sizeAt300 / _page.Size.Height;
         SplitPageWords(_documentFile, pageNumber, sizeFactor, _pageText.Words);
      }
   }
}

void SplitPageWords(string inputFile, int pageNumber, double sizeFactor, IList<DocumentWord> words)
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.Options.RasterizeDocument.Load.Resolution = 300;
   codecs.Options.Pdf.Load.DisplayDepth = 24;
   RasterImage img = codecs.Load(inputFile, pageNumber);

   // Image and metafile for top half of the page's words
   MemoryStream msTop = new MemoryStream();
   var gTempTop = CreateGraphics();
   Metafile mfTop = new Metafile(msTop, gTempTop.GetHdc());
   Graphics gEmfTop = Graphics.FromImage(mfTop);
   RasterImage imgTop = img.Clone();
   imgTop.AddRectangleToRegion(null, new LeadRect(0, 0, imgTop.Width, imgTop.Height), RasterRegionCombineMode.Set);
   gEmfTop.DrawRectangle(Pens.White, 0, 0, imgTop.Width, imgTop.Height);

   // Image and metafile for bottom half of the page's words
   MemoryStream msBot = new MemoryStream();
   var gTempBot = CreateGraphics();
   Metafile mfBot = new Metafile(msBot, gTempBot.GetHdc());
   Graphics gEmfBot = Graphics.FromImage(mfBot);
   RasterImage imgBot = img.Clone();
   imgBot.AddRectangleToRegion(null, new LeadRect(0, 0, imgBot.Width, imgBot.Height), RasterRegionCombineMode.Set);
   gEmfBot.DrawRectangle(Pens.White, 0, 0, imgBot.Width, imgBot.Height);


   foreach (var word in words)
   {
      LeadRect wordBounds = new LeadRect((int)(word.Bounds.X * sizeFactor), (int)(word.Bounds.Y * sizeFactor), (int)(word.Bounds.Width * sizeFactor), (int)(word.Bounds.Height * sizeFactor));
      Font font = SystemFonts.DefaultFont;
      float w0 = gEmfTop.MeasureString(word.Value, font).Width - 4f;
      float factor = wordBounds.Width / w0;
      font = new Font(font.FontFamily, font.Size * factor);
      if (wordBounds.Bottom < img.Height / 2)
      {
         gEmfTop.DrawString(word.Value, font, Brushes.White, wordBounds.X, wordBounds.Y);
         // Add the word rectangle to the "don't erase" region
         imgTop.AddRectangleToRegion(null, wordBounds, RasterRegionCombineMode.AndNotRegion);
      }
      else
      {
         gEmfBot.DrawString(word.Value, font, Brushes.White, wordBounds.X, wordBounds.Y);
         // Add the word rectangle to the "don't erase" region
         imgBot.AddRectangleToRegion(null, wordBounds, RasterRegionCombineMode.AndNotRegion);
      }
      font.Dispose();
   }
   // Fill the non-words area in both images with white to erase it
   FillCommand Fill = new FillCommand(RasterColor.White);
   Fill.Run(imgTop);
   gEmfTop.Dispose(); // finished drawing the text
   Fill.Run(imgBot);
   gEmfBot.Dispose(); // finished drawing the text

   // Create a PDF from the Top half data
   DocumentWriterEmfPage pageTop = new DocumentWriterEmfPage();
   pageTop.Image = imgTop;
   pageTop.EmfHandle = mfTop.GetHenhmetafile();
   DocumentWriter docWriterTop = new DocumentWriter();
   PdfDocumentOptions pdfOptionsTop = docWriterTop.GetOptions(DocumentFormat.Pdf) as PdfDocumentOptions;
   pdfOptionsTop.DocumentType = PdfDocumentType.PdfA;
   pdfOptionsTop.ImageOverText = true;
   pdfOptionsTop.DocumentResolution = imgTop.XResolution;
   pdfOptionsTop.EmptyPageResolution = imgTop.XResolution;
   docWriterTop.SetOptions(DocumentFormat.Pdf, pdfOptionsTop);
   docWriterTop.BeginDocument(inputFile + $"page{pageNumber}_Top.pdf", DocumentFormat.Pdf);
   docWriterTop.AddPage(pageTop);
   docWriterTop.EndDocument();
   mfTop.Dispose();
   gTempTop.ReleaseHdc();
   gTempTop.Dispose();

   // Create a PDF from the Bottom half data
   DocumentWriterEmfPage pageBot = new DocumentWriterEmfPage();
   pageBot.Image = imgBot;
   pageBot.EmfHandle = mfBot.GetHenhmetafile();
   DocumentWriter docWriterBot = new DocumentWriter();
   PdfDocumentOptions pdfOptionsBot = docWriterBot.GetOptions(DocumentFormat.Pdf) as PdfDocumentOptions;
   pdfOptionsBot.DocumentType = PdfDocumentType.PdfA;
   pdfOptionsBot.ImageOverText = true;
   pdfOptionsBot.DocumentResolution = imgBot.XResolution;
   pdfOptionsBot.EmptyPageResolution = imgBot.XResolution;
   docWriterBot.SetOptions(DocumentFormat.Pdf, pdfOptionsBot);
   docWriterBot.BeginDocument(inputFile + $"page{pageNumber}_Bot.pdf", DocumentFormat.Pdf);

   docWriterBot.AddPage(pageBot);
   docWriterBot.EndDocument();
   mfBot.Dispose();
   gTempBot.ReleaseHdc();
   gTempBot.Dispose();
}