File: test_arithmetic.py

package info (click to toggle)
vips 8.18.0-3
  • links: PTS
  • area: main
  • in suites: forky, sid
  • size: 54,344 kB
  • sloc: ansic: 172,638; cpp: 12,257; python: 5,077; sh: 773; perl: 40; makefile: 25; javascript: 6
file content (765 lines) | stat: -rw-r--r-- 23,816 bytes parent folder | download
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
# vim: set fileencoding=utf-8 :

import math
import pytest

import pyvips
from helpers import *


class TestArithmetic:
    def run_arith(self, fn, fmt=all_formats):
        [run_image2('%s image %s %s %s' % (fn.__name__, x, y, z),
                    x.cast(y), x.cast(z), fn)
         for x in self.all_images for y in fmt for z in fmt]

    def run_arith_const(self, fn, fmt=all_formats):
        [run_const('%s scalar %s %s' % (fn.__name__, x, y),
                   fn, x.cast(y), 2)
         for x in self.all_images for y in fmt]
        [run_const('%s vector %s' % (fn.__name__, y),
                   fn, self.colour.cast(y), [1, 2, 3])
         for y in fmt]

    # run a function on an image,
    # 50,50 and 10,10 should have different values on the test image
    def run_imageunary(self, message, im, fn):
        run_cmp(message, im, 50, 50, lambda x: run_fn(fn, x))
        run_cmp(message, im, 10, 10, lambda x: run_fn(fn, x))

    def run_unary(self, images, fn, fmt=all_formats):
        [self.run_imageunary(fn.__name__ + ' image', x.cast(y), fn)
         for x in images for y in fmt]

    # run a function on a pair of images
    # 50,50 and 10,10 should have different values on the test image
    # don't loop over band elements
    def run_imagebinary(self, message, left, right, fn):
        run_cmp2(message, left, right, 50, 50, fn)
        run_cmp2(message, left, right, 10, 10, fn)

    def run_binary(self, images, fn, fmt=all_formats):
        [self.run_imagebinary(f'{fn.__name__ } {y} {x}',
                              x.cast(y), x.cast(z), fn)
         for x in images for y in fmt for z in fmt]

    def versiontuple(version_string):
        return tuple(map(int, (version_string.split('.'))))

    @classmethod
    def setup_class(cls):
        im = pyvips.Image.mask_ideal(100, 100, 0.5,
                                     reject=True, optical=True)
        cls.colour = im * [1, 2, 3] + [2, 3, 4]
        cls.mono = cls.colour.extract_band(1)
        cls.all_images = [cls.mono, cls.colour]

    @classmethod
    def teardown_class(cls):
        cls.colour = None
        cls.mono = None
        cls.all_images = None

    # test all operator overloads we define

    def test_add(self):
        def add(x, y):
            return x + y

        self.run_arith_const(add)
        self.run_arith(add)

    def test_sub(self):
        def sub(x, y):
            return x - y

        self.run_arith_const(sub)
        self.run_arith(sub)

    def test_mul(self):
        def mul(x, y):
            return x * y

        self.run_arith_const(mul)
        self.run_arith(mul)

    def test_div(self):
        def div(x, y):
            return x / y

        # (const / image) needs (image ** -1), which won't work for complex
        self.run_arith_const(div, fmt=noncomplex_formats)
        self.run_arith(div)

    def test_floordiv(self):
        def my_floordiv(x, y):
            return x // y

        # (const // image) needs (image ** -1), which won't work for complex
        self.run_arith_const(my_floordiv, fmt=noncomplex_formats)
        self.run_arith(my_floordiv, fmt=noncomplex_formats)

    def test_pow(self):
        def my_pow(x, y):
            return x ** y

        # (image ** x) won't work for complex images ... just test non-complex
        self.run_arith_const(my_pow, fmt=noncomplex_formats)
        self.run_arith(my_pow, fmt=noncomplex_formats)

    def test_and(self):
        def my_and(x, y):
            # python doesn't allow bools on float
            if isinstance(x, float):
                x = int(x)
            if isinstance(y, float):
                y = int(y)
            return x & y

        self.run_arith_const(my_and, fmt=noncomplex_formats)
        self.run_arith(my_and, fmt=noncomplex_formats)

    def test_or(self):
        def my_or(x, y):
            # python doesn't allow bools on float
            if isinstance(x, float):
                x = int(x)
            if isinstance(y, float):
                y = int(y)
            return x | y

        self.run_arith_const(my_or, fmt=noncomplex_formats)
        self.run_arith(my_or, fmt=noncomplex_formats)

    def test_xor(self):
        def my_xor(x, y):
            # python doesn't allow bools on float
            if isinstance(x, float):
                x = int(x)
            if isinstance(y, float):
                y = int(y)
            return x ^ y

        self.run_arith_const(my_xor, fmt=noncomplex_formats)
        self.run_arith(my_xor, fmt=noncomplex_formats)

    def test_more(self):
        def more(x, y):
            if isinstance(x, pyvips.Image) or isinstance(y, pyvips.Image):
                return x > y
            else:
                if x > y:
                    return 255
                else:
                    return 0

        self.run_arith_const(more)
        self.run_arith(more)

    def test_moreeq(self):
        def moreeq(x, y):
            if isinstance(x, pyvips.Image) or isinstance(y, pyvips.Image):
                return x >= y
            else:
                if x >= y:
                    return 255
                else:
                    return 0

        self.run_arith_const(moreeq)
        self.run_arith(moreeq)

    def test_less(self):
        def less(x, y):
            if isinstance(x, pyvips.Image) or isinstance(y, pyvips.Image):
                return x < y
            else:
                if x < y:
                    return 255
                else:
                    return 0

        self.run_arith_const(less)
        self.run_arith(less)

    def test_lesseq(self):
        def lesseq(x, y):
            if isinstance(x, pyvips.Image) or isinstance(y, pyvips.Image):
                return x <= y
            else:
                if x <= y:
                    return 255
                else:
                    return 0

        self.run_arith_const(lesseq)
        self.run_arith(lesseq)

    def test_equal(self):
        def equal(x, y):
            if isinstance(x, pyvips.Image) or isinstance(y, pyvips.Image):
                return x == y
            else:
                if x == y:
                    return 255
                else:
                    return 0

        self.run_arith_const(equal)
        self.run_arith(equal)

    def test_noteq(self):
        def noteq(x, y):
            if isinstance(x, pyvips.Image) or isinstance(y, pyvips.Image):
                return x != y
            else:
                if x != y:
                    return 255
                else:
                    return 0

        self.run_arith_const(noteq)
        self.run_arith(noteq)

        # comparisons against out of range values should always fail, and
        # comparisons to fractional values should always fail
        x = pyvips.Image.grey(256, 256, uchar=True)
        assert (x == 1000).max() == 0
        assert (x == 12).max() == 255
        assert (x == 12.5).max() == 0

    def test_abs(self):
        def my_abs(x):
            return abs(x)

        im = -self.colour
        self.run_unary([im], my_abs)

    def test_lshift(self):
        def my_lshift(x):
            # python doesn't allow float << int
            if isinstance(x, float):
                x = int(x)
            return x << 2

        # we don't support constant << image, treat as a unary
        self.run_unary(self.all_images, my_lshift, fmt=noncomplex_formats)

    def test_rshift(self):
        def my_rshift(x):
            # python doesn't allow float >> int
            if isinstance(x, float):
                x = int(x)
            return x >> 2

        # we don't support constant >> image, treat as a unary
        self.run_unary(self.all_images, my_rshift, fmt=noncomplex_formats)

    def test_mod(self):
        def my_mod(x):
            return x % 2

        # we don't support constant % image, treat as a unary
        self.run_unary(self.all_images, my_mod, fmt=noncomplex_formats)

    def test_pos(self):
        def my_pos(x):
            return +x

        self.run_unary(self.all_images, my_pos)

    def test_neg(self):
        def my_neg(x):
            return -x

        self.run_unary(self.all_images, my_neg)

    def test_invert(self):
        def my_invert(x):
            if isinstance(x, float):
                x = int(x)
            return ~x & 0xff

        # ~image is trimmed to image max so it's hard to test for all formats
        # just test uchar
        self.run_unary(self.all_images, my_invert,
                       fmt=[pyvips.BandFormat.UCHAR])

    # test the rest of VipsArithmetic

    def test_avg(self):
        im = pyvips.Image.black(50, 100)
        test = im.insert(im + 100, 50, 0, expand=True)

        for fmt in all_formats:
            assert pytest.approx(test.cast(fmt).avg()) == 50

    def test_deviate(self):
        im = pyvips.Image.black(50, 100)
        test = im.insert(im + 100, 50, 0, expand=True)

        for fmt in noncomplex_formats:
            assert pytest.approx(test.cast(fmt).deviate(), abs=0.01) == 50

    def test_polar(self):
        im = pyvips.Image.black(100, 100) + 100
        im = im.complexform(im)

        im = im.polar()

        assert pytest.approx(im.real().avg()) == 100 * 2 ** 0.5
        assert pytest.approx(im.imag().avg()) == 45

    def test_rect(self):
        im = pyvips.Image.black(100, 100)
        im = (im + 100 * 2 ** 0.5).complexform(im + 45)

        im = im.rect()

        assert pytest.approx(im.real().avg()) == 100
        assert pytest.approx(im.imag().avg()) == 100

    def test_conjugate(self):
        im = pyvips.Image.black(100, 100) + 100
        im = im.complexform(im)

        im = im.conj()

        assert pytest.approx(im.real().avg()) == 100
        assert pytest.approx(im.imag().avg()) == -100

    def test_histfind(self):
        im = pyvips.Image.black(50, 100)
        test = im.insert(im + 10, 50, 0, expand=True)

        for fmt in all_formats:
            hist = test.cast(fmt).hist_find()
            assert_almost_equal_objects(hist(0, 0), [5000])
            assert_almost_equal_objects(hist(10, 0), [5000])
            assert_almost_equal_objects(hist(5, 0), [0])

        test = test * [1, 2, 3]

        for fmt in all_formats:
            hist = test.cast(fmt).hist_find(band=0)
            assert_almost_equal_objects(hist(0, 0), [5000])
            assert_almost_equal_objects(hist(10, 0), [5000])
            assert_almost_equal_objects(hist(5, 0), [0])

            hist = test.cast(fmt).hist_find(band=1)
            assert_almost_equal_objects(hist(0, 0), [5000])
            assert_almost_equal_objects(hist(20, 0), [5000])
            assert_almost_equal_objects(hist(5, 0), [0])

    def test_histfind_indexed(self):
        im = pyvips.Image.black(50, 100)
        test = im.insert(im + 10, 50, 0, expand=True)
        index = test // 10

        for x in noncomplex_formats:
            for y in [pyvips.BandFormat.UCHAR, pyvips.BandFormat.USHORT]:
                a = test.cast(x)
                b = index.cast(y)
                hist = a.hist_find_indexed(b)

                assert_almost_equal_objects(hist(0, 0), [0])
                assert_almost_equal_objects(hist(1, 0), [50000])

    def test_histfind_ndim(self):
        im = pyvips.Image.black(100, 100) + [1, 2, 3]

        for fmt in noncomplex_formats:
            hist = im.cast(fmt).hist_find_ndim()

            assert_almost_equal_objects(hist(0, 0)[0], 10000)
            assert_almost_equal_objects(hist(5, 5)[5], 0)

            hist = im.cast(fmt).hist_find_ndim(bins=1)

            assert_almost_equal_objects(hist(0, 0)[0], 10000)
            assert hist.width == 1
            assert hist.height == 1
            assert hist.bands == 1

    def test_hough_circle(self):
        test = pyvips.Image.black(100, 100).draw_circle(100, 50, 50, 40)

        for fmt in all_formats:
            im = test.cast(fmt)
            hough = im.hough_circle(min_radius=35, max_radius=45)

            v, x, y = hough.maxpos()
            vec = hough(x, y)
            r = vec.index(v) + 35

            assert pytest.approx(x) == 50
            assert pytest.approx(y) == 50
            assert pytest.approx(r) == 40

    def test_hough_line(self):
        # hough_line changed the way it codes parameter space (again) in 8.17
        test = pyvips.Image.black(100, 100).draw_line(100, 10, 90, 90, 10)

        for fmt in all_formats:
            im = test.cast(fmt)
            hough = im.hough_line()

            v, x, y = hough.maxpos()

            angle = 180.0 * x // hough.width
            distance = test.height * y // hough.height

            assert pytest.approx(angle) == 45
            assert pytest.approx(distance) == 75

    def test_sin(self):
        def my_sin(x):
            if isinstance(x, pyvips.Image):
                return x.sin()
            else:
                return math.sin(math.radians(x))

        self.run_unary(self.all_images, my_sin, fmt=noncomplex_formats)

    def test_cos(self):
        def my_cos(x):
            if isinstance(x, pyvips.Image):
                return x.cos()
            else:
                return math.cos(math.radians(x))

        self.run_unary(self.all_images, my_cos, fmt=noncomplex_formats)

    def test_tan(self):
        def my_tan(x):
            if isinstance(x, pyvips.Image):
                return x.tan()
            else:
                return math.tan(math.radians(x))

        self.run_unary(self.all_images, my_tan, fmt=noncomplex_formats)

    def test_asin(self):
        def my_asin(x):
            if isinstance(x, pyvips.Image):
                return x.asin()
            else:
                return math.degrees(math.asin(x))

        im = (pyvips.Image.black(100, 100) + [1, 2, 3]) / 3.0
        self.run_unary([im], my_asin, fmt=noncomplex_formats)

    def test_acos(self):
        def my_acos(x):
            if isinstance(x, pyvips.Image):
                return x.acos()
            else:
                return math.degrees(math.acos(x))

        im = (pyvips.Image.black(100, 100) + [1, 2, 3]) / 3.0
        self.run_unary([im], my_acos, fmt=noncomplex_formats)

    def test_atan(self):
        def my_atan(x):
            if isinstance(x, pyvips.Image):
                return x.atan()
            else:
                return math.degrees(math.atan(x))

        im = (pyvips.Image.black(100, 100) + [1, 2, 3]) / 3.0
        self.run_unary([im], my_atan, fmt=noncomplex_formats)

    def test_sinh(self):
        def my_sinh(x):
            if isinstance(x, pyvips.Image):
                return x.sinh()
            else:
                return math.sinh(x)

        self.run_unary(self.all_images, my_sinh, fmt=noncomplex_formats)

    def test_cosh(self):
        def my_cosh(x):
            if isinstance(x, pyvips.Image):
                return x.cosh()
            else:
                return math.cosh(x)

        self.run_unary(self.all_images, my_cosh, fmt=noncomplex_formats)

    def test_tanh(self):
        def my_tanh(x):
            if isinstance(x, pyvips.Image):
                return x.tanh()
            else:
                return math.tanh(x)

        self.run_unary(self.all_images, my_tanh, fmt=noncomplex_formats)

    def test_asinh(self):
        def my_asinh(x):
            if isinstance(x, pyvips.Image):
                return x.asinh()
            else:
                return math.asinh(x)

        im = (pyvips.Image.black(100, 100) + [4, 5, 6]) / 3.0
        self.run_unary([im], my_asinh, fmt=noncomplex_formats)

    def test_acosh(self):
        def my_acosh(x):
            if isinstance(x, pyvips.Image):
                return x.acosh()
            else:
                return math.acosh(x)

        im = (pyvips.Image.black(100, 100) + [4, 5, 6]) / 3.0
        self.run_unary([im], my_acosh, fmt=noncomplex_formats)

    def test_atanh(self):
        def my_atanh(x):
            if isinstance(x, pyvips.Image):
                return x.atanh()
            else:
                return math.atanh(x)

        im = (pyvips.Image.black(100, 100) + [0, 1, 2]) / 3.0
        self.run_unary([im], my_atanh, fmt=noncomplex_formats)

    def test_atan2(self):
        def my_atan2(x, y):
            if isinstance(x, pyvips.Image):
                return x.atan2(y)
            else:
                return math.degrees(math.atan2(x[0], y[0]))

        im = (pyvips.Image.black(100, 100) + [1, 2, 3]) / 3.0
        self.run_binary(im, my_atan2, fmt=noncomplex_formats)

    def test_log(self):
        def my_log(x):
            if isinstance(x, pyvips.Image):
                return x.log()
            else:
                return math.log(x)

        self.run_unary(self.all_images, my_log, fmt=noncomplex_formats)

    def test_log10(self):
        def my_log10(x):
            if isinstance(x, pyvips.Image):
                return x.log10()
            else:
                return math.log10(x)

        self.run_unary(self.all_images, my_log10, fmt=noncomplex_formats)

    def test_exp(self):
        def my_exp(x):
            if isinstance(x, pyvips.Image):
                return x.exp()
            else:
                return math.exp(x)

        self.run_unary(self.all_images, my_exp, fmt=noncomplex_formats)

    def test_exp10(self):
        def my_exp10(x):
            if isinstance(x, pyvips.Image):
                return x.exp10()
            else:
                return math.pow(10, x)

        self.run_unary(self.all_images, my_exp10, fmt=noncomplex_formats)

    def test_floor(self):
        def my_floor(x):
            if isinstance(x, pyvips.Image):
                return x.floor()
            else:
                return math.floor(x)

        self.run_unary(self.all_images, my_floor)

    def test_ceil(self):
        def my_ceil(x):
            if isinstance(x, pyvips.Image):
                return x.ceil()
            else:
                return math.ceil(x)

        self.run_unary(self.all_images, my_ceil)

    def test_rint(self):
        def my_rint(x):
            if isinstance(x, pyvips.Image):
                return x.rint()
            else:
                return round(x)

        self.run_unary(self.all_images, my_rint)

    def test_sign(self):
        def my_sign(x):
            if isinstance(x, pyvips.Image):
                return x.sign()
            else:
                if x > 0:
                    return 1
                elif x < 0:
                    return -1
                else:
                    return 0

        self.run_unary(self.all_images, my_sign)

    def test_max(self):
        test = pyvips.Image.black(100, 100).draw_rect(100, 40, 50, 1, 1)

        for fmt in all_formats:
            v = test.cast(fmt).max()

            assert pytest.approx(v) == 100
            v, x, y = test.cast(fmt).maxpos()
            assert pytest.approx(v) == 100
            assert pytest.approx(x) == 40
            assert pytest.approx(y) == 50

    def test_min(self):
        test = (pyvips.Image.black(100, 100) + 100).draw_rect(0, 40, 50, 1, 1)

        for fmt in all_formats:
            v = test.cast(fmt).min()

            assert pytest.approx(v) == 0
            v, x, y = test.cast(fmt).minpos()
            assert pytest.approx(v) == 0
            assert pytest.approx(x) == 40
            assert pytest.approx(y) == 50

    def test_measure(self):
        im = pyvips.Image.black(50, 50)
        test = im.insert(im + 10, 50, 0, expand=True)

        for x in noncomplex_formats:
            a = test.cast(x)
            matrix = a.measure(2, 1)
            [p1] = matrix(0, 0)
            [p2] = matrix(0, 1)

            assert pytest.approx(p1) == 0
            assert pytest.approx(p2) == 10

    def test_find_trim(self):
        im = pyvips.Image.black(50, 60) + 100
        test = im.embed(10, 20, 200, 300, extend="white")

        for x in unsigned_formats + float_formats:
            a = test.cast(x)
            left, top, width, height = a.find_trim()

            assert left == 10
            assert top == 20
            assert width == 50
            assert height == 60

        test_rgb = test.bandjoin([test, test])
        left, top, width, height = test_rgb.find_trim(line_art=True,
                                                      background=[255, 255,
                                                                  255])
        assert left == 10
        assert top == 20
        assert width == 50
        assert height == 60

    def test_profile(self):
        test = pyvips.Image.black(100, 100).draw_rect(100, 40, 50, 1, 1)

        for fmt in noncomplex_formats:
            columns, rows = test.cast(fmt).profile()

            v, x, y = columns.minpos()
            assert pytest.approx(v) == 50
            assert pytest.approx(x) == 40
            assert pytest.approx(y) == 0

            v, x, y = rows.minpos()
            assert pytest.approx(v) == 40
            assert pytest.approx(x) == 0
            assert pytest.approx(y) == 50

    def test_project(self):
        im = pyvips.Image.black(50, 50)
        test = im.insert(im + 10, 50, 0, expand=True)

        for fmt in noncomplex_formats:
            columns, rows = test.cast(fmt).project()

            assert_almost_equal_objects(columns(10, 0), [0])
            assert_almost_equal_objects(columns(70, 0), [50 * 10])

            assert_almost_equal_objects(rows(0, 10), [50 * 10])

    def test_stats(self):
        im = pyvips.Image.black(50, 50)
        test = im.insert(im + 10, 50, 0, expand=True)

        for x in noncomplex_formats:
            a = test.cast(x)
            matrix = a.stats()

            assert_almost_equal_objects(matrix(0, 0), [a.min()])
            assert_almost_equal_objects(matrix(1, 0), [a.max()])
            assert_almost_equal_objects(matrix(2, 0), [50 * 50 * 10])
            assert_almost_equal_objects(matrix(3, 0), [50 * 50 * 100])
            assert_almost_equal_objects(matrix(4, 0), [a.avg()])
            assert_almost_equal_objects(matrix(5, 0), [a.deviate()])

            assert_almost_equal_objects(matrix(0, 1), [a.min()])
            assert_almost_equal_objects(matrix(1, 1), [a.max()])
            assert_almost_equal_objects(matrix(2, 1), [50 * 50 * 10])
            assert_almost_equal_objects(matrix(3, 1), [50 * 50 * 100])
            assert_almost_equal_objects(matrix(4, 1), [a.avg()])
            assert_almost_equal_objects(matrix(5, 1), [a.deviate()])

    def test_sum(self):
        for fmt in all_formats:
            im = pyvips.Image.black(50, 50)
            im2 = [(im + x).cast(fmt) for x in range(0, 100, 10)]
            im3 = pyvips.Image.sum(im2)
            assert pytest.approx(im3.max()) == sum(range(0, 100, 10))

    def test_clamp(self):
        for fmt in noncomplex_formats:
            im = self.colour
            for x in range(0, 100, 10):
                im2 = (im + x).cast(fmt)
                im3 = im2.clamp()
                assert im3.max() <= 1.0
                assert im3.min() >= 0.0

                im3 = im2.clamp(min=14, max=45)
                assert im3.max() <= 45
                assert im3.min() >= 14

    def test_minpair(self):
        for fmt in noncomplex_formats:
            im = self.colour
            for x in range(0, 100, 10):
                im2 = ((im - x) * 5).cast(fmt)
                im3 = im2.minpair(im)
                im4 = (im2 < im).ifthenelse(im2, im)
                assert (im3 - im4).abs().max() == 0

    def test_maxpair(self):
        for fmt in noncomplex_formats:
            im = self.colour
            for x in range(0, 100, 10):
                im2 = ((im - x) * 5).cast(fmt)
                im3 = im2.maxpair(im)
                im4 = (im2 > im).ifthenelse(im2, im)
                assert (im3 - im4).abs().max() == 0


if __name__ == '__main__':
    pytest.main()