def procDir(tag : Iterable[Tag]) : String = {
    if (tag.isEmpty) ""
    else tag.head.getTagName + ", " + procDir(tag.tail)
  }

  def procMeta(dirs : Iterable[Directory]) : String  = {
    if (dirs.isEmpty) ""
    else ">" + dirs.head.toString + ": { " + procDir(dirs.head.getTags) + "}\n" + procMeta(dirs.tail)
  }

  var metadata : Metadata = ImageMetadataReader.readMetadata(file)
  println( procMeta(metadata.getDirectories))