code: @Deprecated
      public static boolean isSupportedImageFile(final String lcasefn) {
          for (final String ext: supportedImageExtensions) {
              if (lcasefn.endsWith(ext)) {
                  return true;
              }
          }
          return false;
      }
docs: Return if the file is a supported image file by extension.
  @param lcasefn filename
  @return true if is supported image and false otherwise