Rotate and return an image according to its Exif information.

    ROTATION_NEEDED = {
        1: 0,
        2: 0 (Mirrored),
        3: 180,
        4: 180 (Mirrored),
        5: -90 (Mirrored),
        6: -90,
        7: 90 (Mirrored),
        8: 90,
    }

    Args:
        image (PIL.Image.Image): PIL image to rotate
        orientation (): Optional orientation value in [1, 8]

    Returns:
        A :py:class:`~PIL.Image.Image` image.

def autorotate(image, orientation=None):
    """Rotate and return an image according to its Exif information.

    ROTATION_NEEDED = {
        1: 0,
        2: 0 (Mirrored),
        3: 180,
        4: 180 (Mirrored),
        5: -90 (Mirrored),
        6: -90,
        7: 90 (Mirrored),
        8: 90,
    }

    Args:
        image (PIL.Image.Image): PIL image to rotate
        orientation (): Optional orientation value in [1, 8]

    Returns:
        A :py:class:`~PIL.Image.Image` image.

    """
    orientation_value = orientation if orientation else \
        image._getexif().get(EXIF_KEYS.get('Orientation'))
    if orientation_value is None:
        raise ImDirectException("No orientation available in Exif "
                                "tag or given explicitly.")

    if orientation_value in (1, 2):
        i = image
    elif orientation_value in (3, 4):
        i = image.transpose(Image.ROTATE_180)
    elif orientation_value in (5, 6):
        i = image.transpose(Image.ROTATE_270)
    elif orientation_value in (7, 8):
        i = image.transpose(Image.ROTATE_90)
    else:
        i = image

    if orientation_value in (2, 4, 5, 7):
        i = i.transpose(Image.FLIP_LEFT_RIGHT)

    return i