How to Specify Images Converted through PDF in C# .NET?

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

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

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

      // Set dpi to render image
      pdfDoc.DPI = 96;

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

      for (int i = 0; i < count; i++)
      {
        //Convert page to image in target size
        Bitmapbmp = pdfDoc.ToImage(i, 100, 200);
        //Save image 
        bmp.Save("output" + i + ".png", ImageFormat.Png);
      }
    }
  }
}

using System;
using PQScan.PDFToImage;

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

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

      // Set dpi to render whole image
      pdfDoc.DPI = 96;

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