using Spire.Pdf;

using Spire.Pdf.Graphics;

using System;

using System.Drawing;

using System.Drawing.Imaging;

​

namespace PDFtoImage

{

    class Program

    {

        static void Main(string[] args)

        {

            //Create a PdfDocument instance

            PdfDocument pdf = new PdfDocument();

​

            //Load a sample PDF document

            pdf.LoadFromFile("sample.pdf");

​

            //Loop through each page in the PDF

            for (int i = 0; i < pdf.Pages.Count; i++)

            {

                //Convert all pages to images and set the image Dpi

                Image image = pdf.SaveAsImage(i, PdfImageType.Bitmap, 500, 500);

​

                //Save images as PNG format to a specified folder 

                String file = String.Format("Image\\ToImage-{0}.png", i);

                image.Save(file, ImageFormat.Png);

​

            }

        }

    }

}