How To Convert Pdf File Into Jpg Using Csharp

There are plenty of options to do this. I found this code on a forum:
void PdfToJPEG(string inputPdf, string outputJpeg)
{
Leadtools.Codecs.RasterCodecs LeadCodecs = new RasterCodecs();
Leadtools.RasterImage LeadBitmap = LeadCodecs.Load(inputPdf);
LeadCodecs.Save(LeadBitmap, outputJpeg, RasterImageFormat.Jpeg411, 24);
}
The source contains more information here:
http://support.leadtools.com/CS/forums/22379/ShowPost.aspx

Any help on this?

using System.Drawing;
using System.Drawing.Imaging;
using Spire.Pdf;

namespace Pdf2Jpg
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile("sample.pdf");
            Image image = null;
            for (int i = 0; i < doc.Pages.Count; i++)
            {
                image = doc.SaveAsImage(i);
                image.Save(string.Format("img-{0}.jpg", i), ImageFormat.Jpeg);
            }

        }

    }
}