How to Convert PDF to Multi-page TIFF in C# .NET?

using System;
using PQScan.PDFToImage;

namespace PDF2TIFF
{
  class Program
  {
    static void Main(string[] args)
    {
      // Create an instance of PQScan.PDFToImage.PDFDocument object.
      PDFDocument pdfDoc = newPDFDocument();

      // Load a PDF file.
      pdfDoc.LoadPDF("sample.pdf");

      // Save as multi-page tiff image file.
      pdfDoc.ToMultiPageTiff("multipage.tiff");
    }
  }
}