PDFOne .NET
Powerful all-in-one PDF library for .NET

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Home » Newsletter » August 2010

By V. Subhash

In an earlier article, we learned how to export PDF documents to Windows metafiles. This was a bit complicated because .NET does not have an encoder for EMF or WMF, and we had to manage with some unmanaged calls. EMF files are useful only Windows. For wider use, we may need BMP, JPEG, PNG or other raster image formats.

Exporting PDF page content to a raster image format is much more simpler. (In the older article, there were code comments that hinted as much.) The example source code in this article shows us how.

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using Gnostice.PDFOne;

namespace PDFOne_dotNET_Examples {

  class Convert_PDF_To_Images {

    static void Main(string[] args) {

      // Create a metafile
      Metafile metafile;

      // Load a PDF document
      PDFDocument doc =
         new PDFDocument("Your license key");
      // Load the input document and get its page count
      doc.Load("input_doc.pdf");
      Console.WriteLine("Document loaded.");


      // Iterate through all pages in the document
      for (int i = 1; i <= doc.GetPageCount(); i++) {

          // Export current page as a metafile
          metafile = doc.GetPageMetafile(i);

          // Save metafile to PNG and JPEG formats
          metafile.Save(
              "image_of_page_#" + i.ToString() + ".png",
              ImageFormat.Png);
          metafile.Save(
              "image_of_page_#" + i.ToString() + ".jpg",
              ImageFormat.Jpeg);


          Console.Write("\rPage #1-" + i + " exported.");

          // Release any resources used by the metafile
          metafile.Dispose();

      }

      // Clean up
      doc.Close();
      Console.WriteLine("\nDocument closed.");
      doc.Dispose();

      Console.WriteLine("Press Enter to exit.");
      Console.In.ReadLine();

    }
  }
}

What we do here is iterate through all the pages, export page contents as a metafile, and save the metafile as a PNG and JPEG image. That's it. (The program would have been smaller if it were not for the obsession with console output. ☺)