Extract images with itextsharp from a pdf in the correct order

Question

I need to extract one image for page of a pdf,i have a code extracted from another question in stackoverflow to extract images from a pdf, and some times Works all perfect, but other times not extract the images in the order that i hope(first page it will be the first image) and the first image correspond to the first page of the pdf file, this is the code:

 private static int WriteImageFile(string pdf, string path)
        {
            int nfotos = 0;
            try
            {
                // Get a List of Image
                List<System.Drawing.Image> ListImage = ExtractImages(pdf);
                nfotos = ListImage.Count;
                for (int i = 0; i < ListImage.Count; i++)
                {
                    try
                    {
                        ListImage[i].Save(path+ "\\Image" + i + ".bmp", System.Drawing.Imaging.ImageFormat.Bmp);
                                          }
                    catch (Exception e)
                    { MessageBox.Show(e.Message); }
                }

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            return nfotos;
        }


 private static List<System.Drawing.Image> ExtractImages(String PDFSourcePath)
        {
            List<System.Drawing.Image> ImgList = new List<System.Drawing.Image>();

            iTextSharp.text.pdf.RandomAccessFileOrArray RAFObj = null;
            iTextSharp.text.pdf.PdfReader PDFReaderObj = null;
            iTextSharp.text.pdf.PdfObject PDFObj = null;
            iTextSharp.text.pdf.PdfStream PDFStremObj = null;

            try
            {
                RAFObj = new iTextSharp.text.pdf.RandomAccessFileOrArray(PDFSourcePath);
                PDFReaderObj = new iTextSharp.text.pdf.PdfReader(RAFObj, null);
                Form1 formulario = new Form1();
                for (int i = 0; i <= PDFReaderObj.XrefSize - 1; i++)
                {
                    PDFObj = PDFReaderObj.GetPdfObject(i);

                    if ((PDFObj != null) && PDFObj.IsStream())
                    {
                        PDFStremObj = (iTextSharp.text.pdf.PdfStream)PDFObj;
                        iTextSharp.text.pdf.PdfObject subtype = PDFStremObj.Get(iTextSharp.text.pdf.PdfName.SUBTYPE);

                        if ((subtype != null) && subtype.ToString() == iTextSharp.text.pdf.PdfName.IMAGE.ToString())
                        {
                            try
                            {

                                iTextSharp.text.pdf.parser.PdfImageObject PdfImageObj =
                         new iTextSharp.text.pdf.parser.PdfImageObject((iTextSharp.text.pdf.PRStream)PDFStremObj);

                                System.Drawing.Image ImgPDF = PdfImageObj.GetDrawingImage();


                                ImgList.Add(ImgPDF);
                            }
                            catch (Exception)
                            {

                            }
                        }
                    }
                }
                PDFReaderObj.Close();
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
            return ImgList;
        }

So am i doing something wrong? or is any way to know what page is processing to associate a image with a pdf page?