Create a filename by merging path after root directory.

def get_name_from_path(full_path, root_path):
    """Create a filename by merging path after root directory."""
    relative_image_path = os.path.relpath(full_path, root_path)
    return "_".join(relative_image_path.split('.')[:-1]).replace('/', '_')\
        .replace(';', '').replace(':', '')