How to scale content of PDF

using (FileStream inFile = new FileStream(@"..\..\input.pdf", FileMode.Open, FileAccess.Read))
{
   const double scale = 0.5;

   // open the source document
   Document documentIn = new Document(inFile);

   // create the target document
   Document documentOut = new Document();

   // enumerate the pages in the source document
   for (int i = 0; i < documentIn.Pages.Count; i++)
   {
      Page inPage = documentIn.Pages[i];
            
      //append a page that has the SAME size as the original page
      Page outPage = new Page(inPage.Width, inPage.Height);
      documentOut.Pages.Add(outPage);

      //calculate a new position for the content within the page
      double left = (inPage.Width * (1 - scale)) / 2.0;
      double bottom = (inPage.Height * (1 - scale)) / 2.0;

      //calculate a new size of the content
      double width = inPage.Width * scale;
      double height = inPage.Height * scale;

      //scale the box and translate it to the center of the page 
      PageShape pageShape = new PageShape(inPage, left, bottom, width, height);

      outPage.VisualOverlay.Add(pageShape);
   }

   // write the target document to disk
   using (FileStream outFile = new FileStream(@"..\..\output.pdf", FileMode.Create, FileAccess.Write))
   {
      documentOut.Write(outFile);
   }
}

Using inFile As New FileStream("..\..\input.pdf", FileMode.Open, FileAccess.Read)
    Const scale As Double = 0.5

    ' open the source document
    Dim documentIn As New Document(inFile)

    ' create the target document
    Dim documentOut As New Document()

    ' enumerate the pages in the source document
    For i As Integer = 0 To documentIn.Pages.Count - 1
        Dim inPage As Page = documentIn.Pages(i)

        'append a page that has the SAME size as the original page
        Dim outPage As New Page(inPage.Width, inPage.Height)
        documentOut.Pages.Add(outPage)

        'calculate a new position for the content within the page
        Dim left As Double = (inPage.Width * (1 - scale)) / 2.0
        Dim bottom As Double = (inPage.Height * (1 - scale)) / 2.0

        'calculate a new size of the content
        Dim width As Double = inPage.Width * scale
        Dim height As Double = inPage.Height * scale

        'scale the box and translate it to the center of the page 
        Dim pageShape As New PageShape(inPage, left, bottom, width, height)

        outPage.VisualOverlay.Add(pageShape)
    Next

    ' write the target document to disk
    Using outFile As New FileStream("..\..\output.pdf", FileMode.Create, FileAccess.Write)
        documentOut.Write(outFile)
    End Using
End Using