File size: 45,823 Bytes
ecf08bc
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
#    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.

from collections import OrderedDict
from copy import deepcopy

from batchgenerators.augmentations.utils import resize_segmentation
from nnunet.configuration import default_num_threads, RESAMPLING_SEPARATE_Z_ANISO_THRESHOLD
from nnunet.preprocessing.cropping import get_case_identifier_from_npz, ImageCropper
from skimage.transform import resize
from scipy.ndimage.interpolation import map_coordinates
import numpy as np
from batchgenerators.utilities.file_and_folder_operations import *
from multiprocessing.pool import Pool


def get_do_separate_z(spacing, anisotropy_threshold=RESAMPLING_SEPARATE_Z_ANISO_THRESHOLD):
    do_separate_z = (np.max(spacing) / np.min(spacing)) > anisotropy_threshold
    return do_separate_z


def get_lowres_axis(new_spacing):
    axis = np.where(max(new_spacing) / np.array(new_spacing) == 1)[0]  # find which axis is anisotropic
    return axis


def resample_patient(data, seg, original_spacing, target_spacing, order_data=3, order_seg=0, force_separate_z=False,
                     order_z_data=0, order_z_seg=0,
                     separate_z_anisotropy_threshold=RESAMPLING_SEPARATE_Z_ANISO_THRESHOLD):
    """
    :param data:
    :param seg:
    :param original_spacing:
    :param target_spacing:
    :param order_data:
    :param order_seg:
    :param force_separate_z: if None then we dynamically decide how to resample along z, if True/False then always
    /never resample along z separately
    :param order_z_seg: only applies if do_separate_z is True
    :param order_z_data: only applies if do_separate_z is True
    :param separate_z_anisotropy_threshold: if max_spacing > separate_z_anisotropy_threshold * min_spacing (per axis)
    then resample along lowres axis with order_z_data/order_z_seg instead of order_data/order_seg

    :return:
    """
    assert not ((data is None) and (seg is None))
    if data is not None:
        assert len(data.shape) == 4, "data must be c x y z"
    if seg is not None:
        assert len(seg.shape) == 4, "seg must be c x y z"

    if data is not None:
        shape = np.array(data[0].shape)
    else:
        shape = np.array(seg[0].shape)
    new_shape = np.round(((np.array(original_spacing) / np.array(target_spacing)).astype(float) * shape)).astype(int)

    if force_separate_z is not None:
        do_separate_z = force_separate_z
        if force_separate_z:
            axis = get_lowres_axis(original_spacing)
        else:
            axis = None
    else:
        if get_do_separate_z(original_spacing, separate_z_anisotropy_threshold):
            do_separate_z = True
            axis = get_lowres_axis(original_spacing)
        elif get_do_separate_z(target_spacing, separate_z_anisotropy_threshold):
            do_separate_z = True
            axis = get_lowres_axis(target_spacing)
        else:
            do_separate_z = False
            axis = None

    if axis is not None:
        if len(axis) == 3:
            # every axis has the spacing, this should never happen, why is this code here?
            do_separate_z = False
        elif len(axis) == 2:
            # this happens for spacings like (0.24, 1.25, 1.25) for example. In that case we do not want to resample
            # separately in the out of plane axis
            do_separate_z = False
        else:
            pass

    if data is not None:
        data_reshaped = resample_data_or_seg(data, new_shape, False, axis, order_data, do_separate_z,
                                             order_z=order_z_data)
    else:
        data_reshaped = None
    if seg is not None:
        seg_reshaped = resample_data_or_seg(seg, new_shape, True, axis, order_seg, do_separate_z, order_z=order_z_seg)
    else:
        seg_reshaped = None
    return data_reshaped, seg_reshaped


def resample_data_or_seg(data, new_shape, is_seg, axis=None, order=3, do_separate_z=False, order_z=0):
    """
    separate_z=True will resample with order 0 along z
    :param data:
    :param new_shape:
    :param is_seg:
    :param axis:
    :param order:
    :param do_separate_z:
    :param cval:
    :param order_z: only applies if do_separate_z is True
    :return:
    """
    assert len(data.shape) == 4, "data must be (c, x, y, z)"
    if is_seg:
        resize_fn = resize_segmentation
        kwargs = OrderedDict()
    else:
        resize_fn = resize
        kwargs = {'mode': 'edge', 'anti_aliasing': False}
    dtype_data = data.dtype
    shape = np.array(data[0].shape)
    new_shape = np.array(new_shape)
    if np.any(shape != new_shape):
        data = data.astype(float)
        if do_separate_z:
            print("separate z, order in z is", order_z, "order inplane is", order)
            assert len(axis) == 1, "only one anisotropic axis supported"
            axis = axis[0]
            if axis == 0:
                new_shape_2d = new_shape[1:]
            elif axis == 1:
                new_shape_2d = new_shape[[0, 2]]
            else:
                new_shape_2d = new_shape[:-1]

            reshaped_final_data = []
            for c in range(data.shape[0]):
                reshaped_data = []
                for slice_id in range(shape[axis]):
                    if axis == 0:
                        reshaped_data.append(resize_fn(data[c, slice_id], new_shape_2d, order, **kwargs))
                    elif axis == 1:
                        reshaped_data.append(resize_fn(data[c, :, slice_id], new_shape_2d, order, **kwargs))
                    else:
                        reshaped_data.append(resize_fn(data[c, :, :, slice_id], new_shape_2d, order,
                                                       **kwargs))
                reshaped_data = np.stack(reshaped_data, axis)
                if shape[axis] != new_shape[axis]:

                    # The following few lines are blatantly copied and modified from sklearn's resize()
                    rows, cols, dim = new_shape[0], new_shape[1], new_shape[2]
                    orig_rows, orig_cols, orig_dim = reshaped_data.shape

                    row_scale = float(orig_rows) / rows
                    col_scale = float(orig_cols) / cols
                    dim_scale = float(orig_dim) / dim

                    map_rows, map_cols, map_dims = np.mgrid[:rows, :cols, :dim]
                    map_rows = row_scale * (map_rows + 0.5) - 0.5
                    map_cols = col_scale * (map_cols + 0.5) - 0.5
                    map_dims = dim_scale * (map_dims + 0.5) - 0.5

                    coord_map = np.array([map_rows, map_cols, map_dims])
                    if not is_seg or order_z == 0:
                        reshaped_final_data.append(map_coordinates(reshaped_data, coord_map, order=order_z,
                                                                   mode='nearest')[None])
                    else:
                        unique_labels = np.unique(reshaped_data)
                        reshaped = np.zeros(new_shape, dtype=dtype_data)

                        for i, cl in enumerate(unique_labels):
                            reshaped_multihot = np.round(
                                map_coordinates((reshaped_data == cl).astype(float), coord_map, order=order_z,
                                                mode='nearest'))
                            reshaped[reshaped_multihot > 0.5] = cl
                        reshaped_final_data.append(reshaped[None])
                else:
                    reshaped_final_data.append(reshaped_data[None])
            reshaped_final_data = np.vstack(reshaped_final_data)
        else:
            print("no separate z, order", order)
            reshaped = []
            for c in range(data.shape[0]):
                reshaped.append(resize_fn(data[c], new_shape, order, **kwargs)[None])
            reshaped_final_data = np.vstack(reshaped)
        return reshaped_final_data.astype(dtype_data)
    else:
        print("no resampling necessary")
        return data


class GenericPreprocessor(object):
    def __init__(self, normalization_scheme_per_modality, use_nonzero_mask, transpose_forward: (tuple, list), intensityproperties=None):
        """

        :param normalization_scheme_per_modality: dict {0:'nonCT'}
        :param use_nonzero_mask: {0:False}
        :param intensityproperties:
        """
        self.transpose_forward = transpose_forward
        self.intensityproperties = intensityproperties
        self.normalization_scheme_per_modality = normalization_scheme_per_modality
        self.use_nonzero_mask = use_nonzero_mask

        self.resample_separate_z_anisotropy_threshold = RESAMPLING_SEPARATE_Z_ANISO_THRESHOLD

    @staticmethod
    def load_cropped(cropped_output_dir, case_identifier):
        all_data = np.load(os.path.join(cropped_output_dir, "%s.npz" % case_identifier))['data']
        # TODO this is hardcoded does not work for 3D data
        data = all_data[:1].astype(np.float32)
        seg = all_data[1:]
        with open(os.path.join(cropped_output_dir, "%s.pkl" % case_identifier), 'rb') as f:
            properties = pickle.load(f)
        return data, seg, properties

    def resample_and_normalize(self, data, target_spacing, properties, seg=None, force_separate_z=None):
        """
        data and seg must already have been transposed by transpose_forward. properties are the un-transposed values
        (spacing etc)
        :param data:
        :param target_spacing:
        :param properties:
        :param seg:
        :param force_separate_z:
        :return:
        """

        # target_spacing is already transposed, properties["original_spacing"] is not so we need to transpose it!
        # data, seg are already transposed. Double check this using the properties
        original_spacing_transposed = np.array(properties["original_spacing"])[self.transpose_forward]
        before = {
            'spacing': properties["original_spacing"],
            'spacing_transposed': original_spacing_transposed,
            'data.shape (data is transposed)': data.shape
        }

        # remove nans
        data[np.isnan(data)] = 0

        data, seg = resample_patient(data, seg, np.array(original_spacing_transposed), target_spacing, 3, 1,
                                     force_separate_z=force_separate_z, order_z_data=0, order_z_seg=0,
                                     separate_z_anisotropy_threshold=self.resample_separate_z_anisotropy_threshold)
        after = {
            'spacing': target_spacing,
            'data.shape (data is resampled)': data.shape
        }
        print("before:", before, "\nafter: ", after, "\n")

        if seg is not None:  # hippocampus 243 has one voxel with -2 as label. wtf?
            seg[seg < -1] = 0

        properties["size_after_resampling"] = data[0].shape
        properties["spacing_after_resampling"] = target_spacing
        use_nonzero_mask = self.use_nonzero_mask

        assert len(self.normalization_scheme_per_modality) == len(data), "self.normalization_scheme_per_modality " \
                                                                         "must have as many entries as data has " \
                                                                         "modalities"
        assert len(self.use_nonzero_mask) == len(data), "self.use_nonzero_mask must have as many entries as data" \
                                                        " has modalities"

        for c in range(len(data)):
            scheme = self.normalization_scheme_per_modality[c]
            if scheme == "CT":
                # clip to lb and ub from train data foreground and use foreground mn and sd from training data
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                mean_intensity = self.intensityproperties[c]['mean']
                std_intensity = self.intensityproperties[c]['sd']
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                data[c] = (data[c] - mean_intensity) / std_intensity
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == "CT2":
                # clip to lb and ub from train data foreground, use mn and sd form each case for normalization
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                mask = (data[c] > lower_bound) & (data[c] < upper_bound)
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                mn = data[c][mask].mean()
                sd = data[c][mask].std()
                data[c] = (data[c] - mn) / sd
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == 'noNorm':
                pass
            else:
                if use_nonzero_mask[c]:
                    mask = seg[-1] >= 0
                    data[c][mask] = (data[c][mask] - data[c][mask].mean()) / (data[c][mask].std() + 1e-8)
                    data[c][mask == 0] = 0
                else:
                    mn = data[c].mean()
                    std = data[c].std()
                    # print(data[c].shape, data[c].dtype, mn, std)
                    data[c] = (data[c] - mn) / (std + 1e-8)
        return data, seg, properties

    def preprocess_test_case(self, data_files, target_spacing, seg_file=None, force_separate_z=None):
        data, seg, properties = ImageCropper.crop_from_list_of_files(data_files, seg_file)

        data = data.transpose((0, *[i + 1 for i in self.transpose_forward]))
        if not isinstance(seg, type(None)):
            seg = seg.transpose((0, *[i + 1 for i in self.transpose_forward]))

        data, seg, properties = self.resample_and_normalize(data, target_spacing, properties, seg,
                                                            force_separate_z=force_separate_z)
        return data.astype(np.float32), seg, properties

    def _run_internal(self, target_spacing, case_identifier, output_folder_stage, cropped_output_dir, force_separate_z,
                      all_classes):
        data, seg, properties = self.load_cropped(cropped_output_dir, case_identifier)

        data = data.transpose((0, *[i + 1 for i in self.transpose_forward]))
        seg = seg.transpose((0, *[i + 1 for i in self.transpose_forward]))

        data, seg, properties = self.resample_and_normalize(data, target_spacing,
                                                            properties, seg, force_separate_z)

        all_data = np.vstack((data, seg)).astype(np.float32)

        # we need to find out where the classes are and sample some random locations
        # let's do 10.000 samples per class
        # seed this for reproducibility!
        num_samples = 10000
        min_percent_coverage = 0.01 # at least 1% of the class voxels need to be selected, otherwise it may be too sparse
        rndst = np.random.RandomState(1234)
        class_locs = {}
        # TODO add second label (DONE)
        for i, labels in enumerate(all_classes):
            if not bool(labels):
                continue
            class_locs[i] = {}
            for c in labels:
                all_locs = np.argwhere(all_data[1+i] == c)
                if len(all_locs) == 0:
                    class_locs[c] = []
                    continue
                target_num_samples = min(num_samples, len(all_locs))
                target_num_samples = max(target_num_samples, int(np.ceil(len(all_locs) * min_percent_coverage)))

                selected = all_locs[rndst.choice(len(all_locs), target_num_samples, replace=False)]
                class_locs[i][c] = selected
                print(c, target_num_samples)

        properties['class_locations'] = class_locs

        print("saving: ", os.path.join(output_folder_stage, "%s.npz" % case_identifier))
        np.savez_compressed(os.path.join(output_folder_stage, "%s.npz" % case_identifier),
                            data=all_data.astype(np.float32))
        with open(os.path.join(output_folder_stage, "%s.pkl" % case_identifier), 'wb') as f:
            pickle.dump(properties, f)

    def run(self, target_spacings, input_folder_with_cropped_npz, output_folder, data_identifier,
            num_threads=default_num_threads, force_separate_z=None):
        """

        :param target_spacings: list of lists [[1.25, 1.25, 5]]
        :param input_folder_with_cropped_npz: dim: c, x, y, z | npz_file['data'] np.savez_compressed(fname.npz, data=arr)
        :param output_folder:
        :param num_threads:
        :param force_separate_z: None
        :return:
        """
        print("Initializing to run preprocessing")
        print("npz folder:", input_folder_with_cropped_npz)
        print("output_folder:", output_folder)
        list_of_cropped_npz_files = subfiles(input_folder_with_cropped_npz, True, None, ".npz", True)
        maybe_mkdir_p(output_folder)
        num_stages = len(target_spacings)
        if not isinstance(num_threads, (list, tuple, np.ndarray)):
            num_threads = [num_threads] * num_stages

        assert len(num_threads) == num_stages

        # we need to know which classes are present in this dataset so that we can precompute where these classes are
        # located. This is needed for oversampling foreground
        all_classes = load_pickle(join(input_folder_with_cropped_npz, 'dataset_properties.pkl'))['all_classes']

        for i in range(num_stages):
            all_args = []
            output_folder_stage = os.path.join(output_folder, data_identifier + "_stage%d" % i)
            maybe_mkdir_p(output_folder_stage)
            spacing = target_spacings[i]
            for j, case in enumerate(list_of_cropped_npz_files):
                case_identifier = get_case_identifier_from_npz(case)
                args = spacing, case_identifier, output_folder_stage, input_folder_with_cropped_npz, force_separate_z, all_classes
                all_args.append(args)
            p = Pool(num_threads[i])
            p.starmap(self._run_internal, all_args)
            p.close()
            p.join()


class Preprocessor3DDifferentResampling(GenericPreprocessor):
    def resample_and_normalize(self, data, target_spacing, properties, seg=None, force_separate_z=None):
        """
        data and seg must already have been transposed by transpose_forward. properties are the un-transposed values
        (spacing etc)
        :param data:
        :param target_spacing:
        :param properties:
        :param seg:
        :param force_separate_z:
        :return:
        """

        # target_spacing is already transposed, properties["original_spacing"] is not so we need to transpose it!
        # data, seg are already transposed. Double check this using the properties
        original_spacing_transposed = np.array(properties["original_spacing"])[self.transpose_forward]
        before = {
            'spacing': properties["original_spacing"],
            'spacing_transposed': original_spacing_transposed,
            'data.shape (data is transposed)': data.shape
        }

        # remove nans
        data[np.isnan(data)] = 0

        data, seg = resample_patient(data, seg, np.array(original_spacing_transposed), target_spacing, 3, 1,
                                     force_separate_z=force_separate_z, order_z_data=3, order_z_seg=1,
                                     separate_z_anisotropy_threshold=self.resample_separate_z_anisotropy_threshold)
        after = {
            'spacing': target_spacing,
            'data.shape (data is resampled)': data.shape
        }
        print("before:", before, "\nafter: ", after, "\n")

        if seg is not None:  # hippocampus 243 has one voxel with -2 as label. wtf?
            seg[seg < -1] = 0

        properties["size_after_resampling"] = data[0].shape
        properties["spacing_after_resampling"] = target_spacing
        use_nonzero_mask = self.use_nonzero_mask

        assert len(self.normalization_scheme_per_modality) == len(data), "self.normalization_scheme_per_modality " \
                                                                         "must have as many entries as data has " \
                                                                         "modalities"
        assert len(self.use_nonzero_mask) == len(data), "self.use_nonzero_mask must have as many entries as data" \
                                                        " has modalities"

        for c in range(len(data)):
            scheme = self.normalization_scheme_per_modality[c]
            if scheme == "CT":
                # clip to lb and ub from train data foreground and use foreground mn and sd from training data
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                mean_intensity = self.intensityproperties[c]['mean']
                std_intensity = self.intensityproperties[c]['sd']
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                data[c] = (data[c] - mean_intensity) / std_intensity
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == "CT2":
                # clip to lb and ub from train data foreground, use mn and sd form each case for normalization
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                mask = (data[c] > lower_bound) & (data[c] < upper_bound)
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                mn = data[c][mask].mean()
                sd = data[c][mask].std()
                data[c] = (data[c] - mn) / sd
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == 'noNorm':
                pass
            else:
                if use_nonzero_mask[c]:
                    mask = seg[-1] >= 0
                else:
                    mask = np.ones(seg.shape[1:], dtype=bool)
                data[c][mask] = (data[c][mask] - data[c][mask].mean()) / (data[c][mask].std() + 1e-8)
                data[c][mask == 0] = 0
        return data, seg, properties


class Preprocessor3DBetterResampling(GenericPreprocessor):
    """
    This preprocessor always uses force_separate_z=False. It does resampling to the target spacing with third
    order spline for data (just like GenericPreprocessor) and seg (unlike GenericPreprocessor). It never does separate
    resampling in z.
    """
    def resample_and_normalize(self, data, target_spacing, properties, seg=None, force_separate_z=False):
        """
        data and seg must already have been transposed by transpose_forward. properties are the un-transposed values
        (spacing etc)
        :param data:
        :param target_spacing:
        :param properties:
        :param seg:
        :param force_separate_z:
        :return:
        """
        if force_separate_z is not False:
            print("WARNING: Preprocessor3DBetterResampling always uses force_separate_z=False. "
                  "You specified %s. Your choice is overwritten" % str(force_separate_z))
            force_separate_z = False

        # be safe
        assert force_separate_z is False

        # target_spacing is already transposed, properties["original_spacing"] is not so we need to transpose it!
        # data, seg are already transposed. Double check this using the properties
        original_spacing_transposed = np.array(properties["original_spacing"])[self.transpose_forward]
        before = {
            'spacing': properties["original_spacing"],
            'spacing_transposed': original_spacing_transposed,
            'data.shape (data is transposed)': data.shape
        }

        # remove nans
        data[np.isnan(data)] = 0

        data, seg = resample_patient(data, seg, np.array(original_spacing_transposed), target_spacing, 3, 3,
                                     force_separate_z=force_separate_z, order_z_data=99999, order_z_seg=99999,
                                     separate_z_anisotropy_threshold=self.resample_separate_z_anisotropy_threshold)
        after = {
            'spacing': target_spacing,
            'data.shape (data is resampled)': data.shape
        }
        print("before:", before, "\nafter: ", after, "\n")

        if seg is not None:  # hippocampus 243 has one voxel with -2 as label. wtf?
            seg[seg < -1] = 0

        properties["size_after_resampling"] = data[0].shape
        properties["spacing_after_resampling"] = target_spacing
        use_nonzero_mask = self.use_nonzero_mask

        assert len(self.normalization_scheme_per_modality) == len(data), "self.normalization_scheme_per_modality " \
                                                                         "must have as many entries as data has " \
                                                                         "modalities"
        assert len(self.use_nonzero_mask) == len(data), "self.use_nonzero_mask must have as many entries as data" \
                                                        " has modalities"

        for c in range(len(data)):
            scheme = self.normalization_scheme_per_modality[c]
            if scheme == "CT":
                # clip to lb and ub from train data foreground and use foreground mn and sd from training data
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                mean_intensity = self.intensityproperties[c]['mean']
                std_intensity = self.intensityproperties[c]['sd']
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                data[c] = (data[c] - mean_intensity) / std_intensity
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == "CT2":
                # clip to lb and ub from train data foreground, use mn and sd form each case for normalization
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                mask = (data[c] > lower_bound) & (data[c] < upper_bound)
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                mn = data[c][mask].mean()
                sd = data[c][mask].std()
                data[c] = (data[c] - mn) / sd
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == 'noNorm':
                pass
            else:
                if use_nonzero_mask[c]:
                    mask = seg[-1] >= 0
                else:
                    mask = np.ones(seg.shape[1:], dtype=bool)
                data[c][mask] = (data[c][mask] - data[c][mask].mean()) / (data[c][mask].std() + 1e-8)
                data[c][mask == 0] = 0
        return data, seg, properties


class PreprocessorFor2D(GenericPreprocessor):
    def __init__(self, normalization_scheme_per_modality, use_nonzero_mask, transpose_forward: (tuple, list), intensityproperties=None):
        super(PreprocessorFor2D, self).__init__(normalization_scheme_per_modality, use_nonzero_mask,
                                                transpose_forward, intensityproperties)

    def run(self, target_spacings, input_folder_with_cropped_npz, output_folder, data_identifier,
            num_threads=default_num_threads, force_separate_z=None):
        print("Initializing to run preprocessing")
        print("npz folder:", input_folder_with_cropped_npz)
        print("output_folder:", output_folder)
        list_of_cropped_npz_files = subfiles(input_folder_with_cropped_npz, True, None, ".npz", True)
        assert len(list_of_cropped_npz_files) != 0, "set list of files first"
        maybe_mkdir_p(output_folder)
        all_args = []
        num_stages = len(target_spacings)

        # we need to know which classes are present in this dataset so that we can precompute where these classes are
        # located. This is needed for oversampling foreground
        all_classes = load_pickle(join(input_folder_with_cropped_npz, 'dataset_properties.pkl'))['all_classes']

        for i in range(num_stages):
            output_folder_stage = os.path.join(output_folder, data_identifier + "_stage%d" % i)
            maybe_mkdir_p(output_folder_stage)
            spacing = target_spacings[i]
            for j, case in enumerate(list_of_cropped_npz_files):
                case_identifier = get_case_identifier_from_npz(case)
                args = spacing, case_identifier, output_folder_stage, input_folder_with_cropped_npz, force_separate_z, all_classes
                all_args.append(args)
        """
        self._run_internal(spacing, case_identifier, output_folder_stage, input_folder_with_cropped_npz, force_separate_z, all_classes)

        """
        p = Pool(num_threads)
        p.starmap(self._run_internal, all_args)
        p.close()
        p.join()


    def resample_and_normalize(self, data, target_spacing, properties, seg=None, force_separate_z=None):
        original_spacing_transposed = np.array(properties["original_spacing"])[self.transpose_forward]
        before = {
            'spacing': properties["original_spacing"],
            'spacing_transposed': original_spacing_transposed,
            'data.shape (data is transposed)': data.shape
        }
        target_spacing[0] = original_spacing_transposed[0]
        data, seg = resample_patient(data, seg, np.array(original_spacing_transposed), target_spacing, 3, 1,
                                     force_separate_z=force_separate_z, order_z_data=0, order_z_seg=0,
                                     separate_z_anisotropy_threshold=self.resample_separate_z_anisotropy_threshold)
        after = {
            'spacing': target_spacing,
            'data.shape (data is resampled)': data.shape
        }
        print("before:", before, "\nafter: ", after, "\n")

        if seg is not None:  # hippocampus 243 has one voxel with -2 as label. wtf?
            seg[seg < -1] = 0

        properties["size_after_resampling"] = data[0].shape
        properties["spacing_after_resampling"] = target_spacing
        use_nonzero_mask = self.use_nonzero_mask

        assert len(self.normalization_scheme_per_modality) == len(data), "self.normalization_scheme_per_modality " \
                                                                         "must have as many entries as data has " \
                                                                         "modalities"
        assert len(self.use_nonzero_mask) == len(data), "self.use_nonzero_mask must have as many entries as data" \
                                                        " has modalities"

        print("normalization...")

        for c in range(len(data)):
            scheme = self.normalization_scheme_per_modality[c]
            if scheme == "CT":
                # clip to lb and ub from train data foreground and use foreground mn and sd from training data
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                mean_intensity = self.intensityproperties[c]['mean']
                std_intensity = self.intensityproperties[c]['sd']
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                data[c] = (data[c] - mean_intensity) / std_intensity
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == "CT2":
                # clip to lb and ub from train data foreground, use mn and sd form each case for normalization
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                mask = (data[c] > lower_bound) & (data[c] < upper_bound)
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                mn = data[c][mask].mean()
                sd = data[c][mask].std()
                data[c] = (data[c] - mn) / sd
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == 'noNorm':
                pass
            else:
                if use_nonzero_mask[c]:
                    mask = seg[-1] >= 0
                else:
                    if seg is not None:
                        mask = np.ones(seg.shape[1:], dtype=bool)
                    else:
                        mask = np.ones(data[c].shape, dtype=bool)
                data[c][mask] = (data[c][mask] - data[c][mask].mean()) / (data[c][mask].std() + 1e-8)
                data[c][mask == 0] = 0
        print("normalization done")
        return data, seg, properties


class PreprocessorFor3D_LeaveOriginalZSpacing(GenericPreprocessor):
    """
    3d_lowres and 3d_fullres are not resampled along z!
    """
    def resample_and_normalize(self, data, target_spacing, properties, seg=None, force_separate_z=None):
        """
        if target_spacing[0] is None or nan we use original_spacing_transposed[0] (no resampling along z)
        :param data:
        :param target_spacing:
        :param properties:
        :param seg:
        :param force_separate_z:
        :return:
        """
        original_spacing_transposed = np.array(properties["original_spacing"])[self.transpose_forward]
        before = {
            'spacing': properties["original_spacing"],
            'spacing_transposed': original_spacing_transposed,
            'data.shape (data is transposed)': data.shape
        }

        # remove nans
        data[np.isnan(data)] = 0
        target_spacing = deepcopy(target_spacing)
        if target_spacing[0] is None or np.isnan(target_spacing[0]):
            target_spacing[0] = original_spacing_transposed[0]
        #print(target_spacing, original_spacing_transposed)
        data, seg = resample_patient(data, seg, np.array(original_spacing_transposed), target_spacing, 3, 1,
                                     force_separate_z=force_separate_z, order_z_data=0, order_z_seg=0,
                                     separate_z_anisotropy_threshold=self.resample_separate_z_anisotropy_threshold)
        after = {
            'spacing': target_spacing,
            'data.shape (data is resampled)': data.shape
        }
        st = "before:" + str(before) + '\nafter' + str(after) + "\n"
        print(st)

        if seg is not None:  # hippocampus 243 has one voxel with -2 as label. wtf?
            seg[seg < -1] = 0

        properties["size_after_resampling"] = data[0].shape
        properties["spacing_after_resampling"] = target_spacing
        use_nonzero_mask = self.use_nonzero_mask

        assert len(self.normalization_scheme_per_modality) == len(data), "self.normalization_scheme_per_modality " \
                                                                         "must have as many entries as data has " \
                                                                         "modalities"
        assert len(self.use_nonzero_mask) == len(data), "self.use_nonzero_mask must have as many entries as data" \
                                                        " has modalities"

        for c in range(len(data)):
            scheme = self.normalization_scheme_per_modality[c]
            if scheme == "CT":
                # clip to lb and ub from train data foreground and use foreground mn and sd from training data
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                mean_intensity = self.intensityproperties[c]['mean']
                std_intensity = self.intensityproperties[c]['sd']
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                data[c] = (data[c] - mean_intensity) / std_intensity
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == "CT2":
                # clip to lb and ub from train data foreground, use mn and sd form each case for normalization
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                mask = (data[c] > lower_bound) & (data[c] < upper_bound)
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                mn = data[c][mask].mean()
                sd = data[c][mask].std()
                data[c] = (data[c] - mn) / sd
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == 'noNorm':
                pass
            else:
                if use_nonzero_mask[c]:
                    mask = seg[-1] >= 0
                else:
                    mask = np.ones(seg.shape[1:], dtype=bool)
                data[c][mask] = (data[c][mask] - data[c][mask].mean()) / (data[c][mask].std() + 1e-8)
                data[c][mask == 0] = 0
        return data, seg, properties

    def run(self, target_spacings, input_folder_with_cropped_npz, output_folder, data_identifier,
            num_threads=default_num_threads, force_separate_z=None):
        for i in range(len(target_spacings)):
            target_spacings[i][0] = None
        super().run(target_spacings, input_folder_with_cropped_npz, output_folder, data_identifier,
                    default_num_threads, force_separate_z)


class PreprocessorFor3D_NoResampling(GenericPreprocessor):
    def resample_and_normalize(self, data, target_spacing, properties, seg=None, force_separate_z=None):
        """
        if target_spacing[0] is None or nan we use original_spacing_transposed[0] (no resampling along z)
        :param data:
        :param target_spacing:
        :param properties:
        :param seg:
        :param force_separate_z:
        :return:
        """
        original_spacing_transposed = np.array(properties["original_spacing"])[self.transpose_forward]
        before = {
            'spacing': properties["original_spacing"],
            'spacing_transposed': original_spacing_transposed,
            'data.shape (data is transposed)': data.shape
        }

        # remove nans
        data[np.isnan(data)] = 0
        target_spacing = deepcopy(original_spacing_transposed)
        #print(target_spacing, original_spacing_transposed)
        data, seg = resample_patient(data, seg, np.array(original_spacing_transposed), target_spacing, 3, 1,
                                     force_separate_z=force_separate_z, order_z_data=0, order_z_seg=0,
                                     separate_z_anisotropy_threshold=self.resample_separate_z_anisotropy_threshold)
        after = {
            'spacing': target_spacing,
            'data.shape (data is resampled)': data.shape
        }
        st = "before:" + str(before) + '\nafter' + str(after) + "\n"
        print(st)

        if seg is not None:  # hippocampus 243 has one voxel with -2 as label. wtf?
            seg[seg < -1] = 0

        properties["size_after_resampling"] = data[0].shape
        properties["spacing_after_resampling"] = target_spacing
        use_nonzero_mask = self.use_nonzero_mask

        assert len(self.normalization_scheme_per_modality) == len(data), "self.normalization_scheme_per_modality " \
                                                                         "must have as many entries as data has " \
                                                                         "modalities"
        assert len(self.use_nonzero_mask) == len(data), "self.use_nonzero_mask must have as many entries as data" \
                                                        " has modalities"

        for c in range(len(data)):
            scheme = self.normalization_scheme_per_modality[c]
            if scheme == "CT":
                # clip to lb and ub from train data foreground and use foreground mn and sd from training data
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                mean_intensity = self.intensityproperties[c]['mean']
                std_intensity = self.intensityproperties[c]['sd']
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                data[c] = (data[c] - mean_intensity) / std_intensity
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == "CT2":
                # clip to lb and ub from train data foreground, use mn and sd form each case for normalization
                assert self.intensityproperties is not None, "ERROR: if there is a CT then we need intensity properties"
                lower_bound = self.intensityproperties[c]['percentile_00_5']
                upper_bound = self.intensityproperties[c]['percentile_99_5']
                mask = (data[c] > lower_bound) & (data[c] < upper_bound)
                data[c] = np.clip(data[c], lower_bound, upper_bound)
                mn = data[c][mask].mean()
                sd = data[c][mask].std()
                data[c] = (data[c] - mn) / sd
                if use_nonzero_mask[c]:
                    data[c][seg[-1] < 0] = 0
            elif scheme == 'noNorm':
                pass
            else:
                if use_nonzero_mask[c]:
                    mask = seg[-1] >= 0
                else:
                    mask = np.ones(seg.shape[1:], dtype=bool)
                data[c][mask] = (data[c][mask] - data[c][mask].mean()) / (data[c][mask].std() + 1e-8)
                data[c][mask == 0] = 0
        return data, seg, properties


class PreprocessorFor2D_noNormalization(GenericPreprocessor):
    def resample_and_normalize(self, data, target_spacing, properties, seg=None, force_separate_z=None):
        original_spacing_transposed = np.array(properties["original_spacing"])[self.transpose_forward]
        before = {
            'spacing': properties["original_spacing"],
            'spacing_transposed': original_spacing_transposed,
            'data.shape (data is transposed)': data.shape
        }
        target_spacing[0] = original_spacing_transposed[0]
        data, seg = resample_patient(data, seg, np.array(original_spacing_transposed), target_spacing, 3, 1,
                                     force_separate_z=force_separate_z, order_z_data=0, order_z_seg=0,
                                     separate_z_anisotropy_threshold=self.resample_separate_z_anisotropy_threshold)
        after = {
            'spacing': target_spacing,
            'data.shape (data is resampled)': data.shape
        }
        print("before:", before, "\nafter: ", after, "\n")

        if seg is not None:  # hippocampus 243 has one voxel with -2 as label. wtf?
            seg[seg < -1] = 0

        properties["size_after_resampling"] = data[0].shape
        properties["spacing_after_resampling"] = target_spacing
        use_nonzero_mask = self.use_nonzero_mask

        assert len(self.normalization_scheme_per_modality) == len(data), "self.normalization_scheme_per_modality " \
                                                                         "must have as many entries as data has " \
                                                                         "modalities"
        assert len(self.use_nonzero_mask) == len(data), "self.use_nonzero_mask must have as many entries as data" \
                                                        " has modalities"
        return data, seg, properties