def transparency2float(value: int) -> float:
    """
    Returns transparency value as float from 0 to 1, 0 for no transparency
    (opaque) and 1 for 100% transparency.

    Args:
        value: DXF integer transparency value, 0 for 100% transparency and 255
            for opaque

    """
    # 255 -> 0.
    # 0 -> 1.
    return 1. - float(int(value) & 0xFF) / 255.