Converter .pdf para uma imagem

public  void getImage(String dir, String fileDir, String fileName) throws FileNotFoundException, IOException {
        File pdfFile = new File(fileDir);
       
        RandomAccessFile raf = new RandomAccessFile(pdfFile, "r");
        FileChannel channel = raf.getChannel();
        ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());
        PDFFile pdf = new PDFFile(buf);
        PDFPage page = pdf.getPage(1);

        Rectangle rect = new Rectangle(0, 0, (int) page.getBBox().getWidth(),
                (int) page.getBBox().getHeight());
        BufferedImage bufferedImage = new BufferedImage(rect.width, rect.height,
                BufferedImage.TYPE_INT_RGB);

        Image image = page.getImage(rect.width, rect.height,
                rect, 
                null, 
                true, 
                true 
                );
        Graphics2D bufImageGraphics = bufferedImage.createGraphics();
        bufImageGraphics.drawImage(image, 0, 0, null);
        ImageIO.write(bufferedImage, "jpg", new File(dir + "imagem.jpg"));

    }