Files

355 lines
12 KiB
Python

import numpy as np
from numpy.testing import (assert_array_almost_equal as assert_close,
assert_equal, assert_raises)
from scipy import ndimage as ndi
from skimage.feature import peak
np.random.seed(21)
def test_trivial_case():
trivial = np.zeros((25, 25))
peak_indices = peak.peak_local_max(trivial, min_distance=1, indices=True)
assert type(peak_indices) is np.ndarray
assert not peak_indices # inherent boolean-ness of empty list
peaks = peak.peak_local_max(trivial, min_distance=1, indices=False)
assert (peaks.astype(np.bool) == trivial).all()
def test_noisy_peaks():
peak_locations = [(7, 7), (7, 13), (13, 7), (13, 13)]
# image with noise of amplitude 0.8 and peaks of amplitude 1
image = 0.8 * np.random.rand(20, 20)
for r, c in peak_locations:
image[r, c] = 1
peaks_detected = peak.peak_local_max(image, min_distance=5)
assert len(peaks_detected) == len(peak_locations)
for loc in peaks_detected:
assert tuple(loc) in peak_locations
def test_relative_threshold():
image = np.zeros((5, 5), dtype=np.uint8)
image[1, 1] = 10
image[3, 3] = 20
peaks = peak.peak_local_max(image, min_distance=1, threshold_rel=0.5)
assert len(peaks) == 1
assert_close(peaks, [(3, 3)])
def test_absolute_threshold():
image = np.zeros((5, 5), dtype=np.uint8)
image[1, 1] = 10
image[3, 3] = 20
peaks = peak.peak_local_max(image, min_distance=1, threshold_abs=10)
assert len(peaks) == 1
assert_close(peaks, [(3, 3)])
def test_constant_image():
image = 128 * np.ones((20, 20), dtype=np.uint8)
peaks = peak.peak_local_max(image, min_distance=1)
assert len(peaks) == 0
def test_flat_peak():
image = np.zeros((5, 5), dtype=np.uint8)
image[1:3, 1:3] = 10
peaks = peak.peak_local_max(image, min_distance=1)
assert len(peaks) == 4
def test_num_peaks():
image = np.zeros((7, 7), dtype=np.uint8)
image[1, 1] = 10
image[1, 3] = 11
image[1, 5] = 12
image[3, 5] = 8
image[5, 3] = 7
assert len(peak.peak_local_max(image, min_distance=1, threshold_abs=0)) == 5
peaks_limited = peak.peak_local_max(
image, min_distance=1, threshold_abs=0, num_peaks=2)
assert len(peaks_limited) == 2
assert (1, 3) in peaks_limited
assert (1, 5) in peaks_limited
peaks_limited = peak.peak_local_max(
image, min_distance=1, threshold_abs=0, num_peaks=4)
assert len(peaks_limited) == 4
assert (1, 3) in peaks_limited
assert (1, 5) in peaks_limited
assert (1, 1) in peaks_limited
assert (3, 5) in peaks_limited
def test_num_peaks3D():
# Issue 1354: the old code only hold for 2D arrays
# and this code would die with IndexError
image = np.zeros((10, 10, 100))
image[5,5,::5] = np.arange(20)
peaks_limited = peak.peak_local_max(image, min_distance=1, num_peaks=2)
assert len(peaks_limited) == 2
def test_reorder_labels():
image = np.random.uniform(size=(40, 60))
i, j = np.mgrid[0:40, 0:60]
labels = 1 + (i >= 20) + (j >= 30) * 2
labels[labels == 4] = 5
i, j = np.mgrid[-3:4, -3:4]
footprint = (i * i + j * j <= 9)
expected = np.zeros(image.shape, float)
for imin, imax in ((0, 20), (20, 40)):
for jmin, jmax in ((0, 30), (30, 60)):
expected[imin:imax, jmin:jmax] = ndi.maximum_filter(
image[imin:imax, jmin:jmax], footprint=footprint)
expected = (expected == image)
result = peak.peak_local_max(image, labels=labels, min_distance=1,
threshold_rel=0, footprint=footprint,
indices=False, exclude_border=False)
assert (result == expected).all()
def test_indices_with_labels():
image = np.random.uniform(size=(40, 60))
i, j = np.mgrid[0:40, 0:60]
labels = 1 + (i >= 20) + (j >= 30) * 2
i, j = np.mgrid[-3:4, -3:4]
footprint = (i * i + j * j <= 9)
expected = np.zeros(image.shape, float)
for imin, imax in ((0, 20), (20, 40)):
for jmin, jmax in ((0, 30), (30, 60)):
expected[imin:imax, jmin:jmax] = ndi.maximum_filter(
image[imin:imax, jmin:jmax], footprint=footprint)
expected = (expected == image)
result = peak.peak_local_max(image, labels=labels, min_distance=1,
threshold_rel=0, footprint=footprint,
indices=True, exclude_border=False)
assert (result == np.transpose(expected.nonzero())).all()
def test_ndarray_indices_false():
nd_image = np.zeros((5,5,5))
nd_image[2,2,2] = 1
peaks = peak.peak_local_max(nd_image, min_distance=1, indices=False)
assert (peaks == nd_image.astype(np.bool)).all()
def test_ndarray_exclude_border():
nd_image = np.zeros((5,5,5))
nd_image[[1,0,0],[0,1,0],[0,0,1]] = 1
nd_image[3,0,0] = 1
nd_image[2,2,2] = 1
expected = np.zeros_like(nd_image, dtype=np.bool)
expected[2,2,2] = True
expectedNoBorder = nd_image > 0
result = peak.peak_local_max(nd_image, min_distance=2,
exclude_border=2, indices=False)
assert_equal(result, expected)
# Check that bools work as expected
assert_equal(
peak.peak_local_max(nd_image, min_distance=2,
exclude_border=2, indices=False),
peak.peak_local_max(nd_image, min_distance=2,
exclude_border=True, indices=False)
)
assert_equal(
peak.peak_local_max(nd_image, min_distance=2,
exclude_border=0, indices=False),
peak.peak_local_max(nd_image, min_distance=2,
exclude_border=False, indices=False)
)
# Check both versions with no border
assert_equal(
peak.peak_local_max(nd_image, min_distance=2,
exclude_border=0, indices=False),
expectedNoBorder,
)
assert_equal(
peak.peak_local_max(nd_image,
exclude_border=False, indices=False),
expectedNoBorder,
)
def test_empty():
image = np.zeros((10, 20))
labels = np.zeros((10, 20), int)
result = peak.peak_local_max(image, labels=labels,
footprint=np.ones((3, 3), bool),
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(~ result)
def test_one_point():
image = np.zeros((10, 20))
labels = np.zeros((10, 20), int)
image[5, 5] = 1
labels[5, 5] = 1
result = peak.peak_local_max(image, labels=labels,
footprint=np.ones((3, 3), bool),
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(result == (labels == 1))
def test_adjacent_and_same():
image = np.zeros((10, 20))
labels = np.zeros((10, 20), int)
image[5, 5:6] = 1
labels[5, 5:6] = 1
result = peak.peak_local_max(image, labels=labels,
footprint=np.ones((3, 3), bool),
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(result == (labels == 1))
def test_adjacent_and_different():
image = np.zeros((10, 20))
labels = np.zeros((10, 20), int)
image[5, 5] = 1
image[5, 6] = .5
labels[5, 5:6] = 1
expected = (image == 1)
result = peak.peak_local_max(image, labels=labels,
footprint=np.ones((3, 3), bool),
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(result == expected)
result = peak.peak_local_max(image, labels=labels,
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(result == expected)
def test_not_adjacent_and_different():
image = np.zeros((10, 20))
labels = np.zeros((10, 20), int)
image[5, 5] = 1
image[5, 8] = .5
labels[image > 0] = 1
expected = (labels == 1)
result = peak.peak_local_max(image, labels=labels,
footprint=np.ones((3, 3), bool),
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(result == expected)
def test_two_objects():
image = np.zeros((10, 20))
labels = np.zeros((10, 20), int)
image[5, 5] = 1
image[5, 15] = .5
labels[5, 5] = 1
labels[5, 15] = 2
expected = (labels > 0)
result = peak.peak_local_max(image, labels=labels,
footprint=np.ones((3, 3), bool),
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(result == expected)
def test_adjacent_different_objects():
image = np.zeros((10, 20))
labels = np.zeros((10, 20), int)
image[5, 5] = 1
image[5, 6] = .5
labels[5, 5] = 1
labels[5, 6] = 2
expected = (labels > 0)
result = peak.peak_local_max(image, labels=labels,
footprint=np.ones((3, 3), bool),
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(result == expected)
def test_four_quadrants():
image = np.random.uniform(size=(40, 60))
i, j = np.mgrid[0:40, 0:60]
labels = 1 + (i >= 20) + (j >= 30) * 2
i, j = np.mgrid[-3:4, -3:4]
footprint = (i * i + j * j <= 9)
expected = np.zeros(image.shape, float)
for imin, imax in ((0, 20), (20, 40)):
for jmin, jmax in ((0, 30), (30, 60)):
expected[imin:imax, jmin:jmax] = ndi.maximum_filter(
image[imin:imax, jmin:jmax], footprint=footprint)
expected = (expected == image)
result = peak.peak_local_max(image, labels=labels, footprint=footprint,
min_distance=1, threshold_rel=0,
indices=False, exclude_border=False)
assert np.all(result == expected)
def test_disk():
'''regression test of img-1194, footprint = [1]
Test peak.peak_local_max when every point is a local maximum
'''
image = np.random.uniform(size=(10, 20))
footprint = np.array([[1]])
result = peak.peak_local_max(image, labels=np.ones((10, 20)),
footprint=footprint,
min_distance=1, threshold_rel=0,
threshold_abs=-1, indices=False,
exclude_border=False)
assert np.all(result)
result = peak.peak_local_max(image, footprint=footprint, threshold_abs=-1,
indices=False, exclude_border=False)
assert np.all(result)
def test_3D():
image = np.zeros((30, 30, 30))
image[15, 15, 15] = 1
image[5, 5, 5] = 1
assert_equal(peak.peak_local_max(image, min_distance=10, threshold_rel=0),
[[15, 15, 15]])
assert_equal(peak.peak_local_max(image, min_distance=6, threshold_rel=0),
[[15, 15, 15]])
assert_equal(peak.peak_local_max(image, min_distance=10, threshold_rel=0,
exclude_border=False),
[[5, 5, 5], [15, 15, 15]])
assert_equal(peak.peak_local_max(image, min_distance=5, threshold_rel=0),
[[5, 5, 5], [15, 15, 15]])
def test_4D():
image = np.zeros((30, 30, 30, 30))
image[15, 15, 15, 15] = 1
image[5, 5, 5, 5] = 1
assert_equal(peak.peak_local_max(image, min_distance=10, threshold_rel=0),
[[15, 15, 15, 15]])
assert_equal(peak.peak_local_max(image, min_distance=6, threshold_rel=0),
[[15, 15, 15, 15]])
assert_equal(peak.peak_local_max(image, min_distance=10, threshold_rel=0,
exclude_border=False),
[[5, 5, 5, 5], [15, 15, 15, 15]])
assert_equal(peak.peak_local_max(image, min_distance=5, threshold_rel=0),
[[5, 5, 5, 5], [15, 15, 15, 15]])
def test_threshold_rel_default():
image = np.ones((5, 5))
image[2, 2] = 1
assert len(peak.peak_local_max(image)) == 0
image[2, 2] = 2
assert_equal(peak.peak_local_max(image), [[2, 2]])
image[2, 2] = 0
assert len(peak.peak_local_max(image, min_distance=0)) == image.size - 1
if __name__ == '__main__':
from numpy import testing
testing.run_module_suite()