# Copyright 2019 Akiomi Kamakura
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import numpy as np
from PIL import Image


def invert(im):
    """Inverts an image.

    Arguments:
        im: An image.

    Returns:
        The output image.
    """

    # NOTE: `ImageChops.invert` and `im.point` are slower than numpy
    return Image.fromarray(255 - np.asarray(im))
