code: public int getIfdImagesCount() {
      int c = 0;
      if (metadata.contains("IFD")) {
        List<TiffObject> l = getMetadataList("IFD");
        int n = 0;
        for (TiffObject to : l) {
          if (to instanceof IFD) {
            IFD ifd = (IFD) to;
            if (ifd.isImage())
              n++;
          }
        }
        c = n;
      }
      return c;
    }
docs: Gets the images count (main images and thumbnails).
  
  @return the ifd count