class InvalidVersionError(Exception):
    """Unknown version.

    We don't know how to parse the version of ND2 that we were given.

    """
    pass


class NoImageError(Exception):
    """No image found.

    Some apparent images in ND2s are just completely blank placeholders. These are used when the number of images per
    cycle are unequal (e.g. if you take fluorescent images every 2 minutes, and bright field images every minute).

    """
    pass