title: extract images from pdf using pdfbox
body: <p>I m trying to extract images from a pdf using pdfbox. The example pdf <a href="http://www.ignou.ac.in/upload/questionpaper/CS-74.PDF" rel="noreferrer">here</a></p>
  
  <p>But i m getting blank images only.</p>
  
  <p>The code i m trying:-</p>
  
  <pre><code>public static void main(String[] args) {
     PDFImageExtract obj = new PDFImageExtract();
      try {
          obj.read_pdf();
      } catch (IOException ex) {
          System.out.println("" + ex);
      }
  
  }
  
   void read_pdf() throws IOException {
      PDDocument document = null; 
      try {
          document = PDDocument.load("C:\\Users\\Pradyut\\Documents\\MCS-034.pdf");
      } catch (IOException ex) {
          System.out.println("" + ex);
      }
      List pages = document.getDocumentCatalog().getAllPages();
      Iterator iter = pages.iterator(); 
      int i =1;
      String name = null;
  
      while (iter.hasNext()) {
          PDPage page = (PDPage) iter.next();
          PDResources resources = page.getResources();
          Map pageImages = resources.getImages();
          if (pageImages != null) { 
              Iterator imageIter = pageImages.keySet().iterator();
              while (imageIter.hasNext()) {
                  String key = (String) imageIter.next();
                  PDXObjectImage image = (PDXObjectImage) pageImages.get(key);
                  image.write2file("C:\\Users\\Pradyut\\Documents\\image" + i);
                  i ++;
              }
          }
      }
  
  }
  </code></pre>
  
  <p>Thanks</p>