#    Copyright 2020 Division of Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
#
#    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


def to_one_hot(seg, all_seg_labels=None):
    if all_seg_labels is None:
        all_seg_labels = np.unique(seg)
    result = np.zeros((len(all_seg_labels), *seg.shape), dtype=seg.dtype)
    for i, l in enumerate(all_seg_labels):
        result[i][seg == l] = 1
    return result