def read_label_map(path_to_labels):
    """Read from the label map file and return a class dictionary which
    maps class id (int) to the corresponding display name (string).
    This functions expects a txt, not pbtxt file
    """
    with open(path_to_labels,'r') as f:
        return {i: c for i,c in enumerate(f.read().split('\n'))}