/** Read the original picture and scale down the thumb */
  private Image readThumb(PM_Picture picture, File fileThumbnail) {

    // Now make a thumb nail file and store it on the disk.
    // So you can read it in future from the disk.
    picture.readImageOriginal();
    Image imageOriginal = picture.getImageOriginal();
    Image imageThumbnail = makeThumbnail(imageOriginal);
    if (imageThumbnail == null) {
      return null;
    }
    PM_UtilsGrafik.writeThumbnail(fileThumbnail, imageThumbnail);

    setEXIFpictureMetadaten(picture);
    // add high and width from the image-original file.
    picture.meta.setImageSize(PM_UtilsGrafik.getImageSize(imageOriginal));
    PM_Picture.flushAllImagesOriginal();

    return imageThumbnail;
  }