How to Convert PDF to GIF in C# .NET?

using System;
using System.Drawing;
using System.Drawing.Imaging;
using PQScan.PDFToImage;

namespace PDF2GIF
{
  class Program
  {
    static void Main(string[] args)
    {
      // Create an instance of PQScan.PDFToImage.PDFDocument object.
      PDFDocument pdfDoc = new PDFDocument();

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

      // Get its page count.
      int count = pdfDoc.PageCount;

      for (int i = 0; i < count; i++)
      {
        // Change PDF page to image.
        Bitmap gifImage = pdfDoc.ToImage(i);

        // Save image as gif image format.
        gifImage.Save("output" + i + ".gif", ImageFormat.Gif);
      }
    }
  }
}

using System;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using PQScan.PDFToImage;

namespace PDFToGIF
{
  class Program
  {
    static void Main(string[] args)
    {
      // Make a new instance of PQScan.PDFToImage.PDFDocument object.
      PDFDocument pdf = new PDFDocument();

      // Create a file stream with PDF information.
      FileStream stream = new FileStream("sample.pdf", FileMode.Open);

      // Load PDF document from file stream.
      pdf.LoadPDF(stream);

      // Set a target width for gif image.
      int width = pdf.GetPageWidth(0) / 2;

      // Set a target height for gif image.
      int height = pdf.GetPageHeight(0) / 2;

      // Convert the first page of PDF file to image with the desired size.
      Bitmap gif = pdf.ToImage(0, width, height);

      // Save image to gif format.
      gif.Save("result.gif", ImageFormat.Gif);
    }
  }
}