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scikit-image/skimage/segmentation/tests/test_felzenszwalb.py
T
Tony S Yu f2d5b109e9 Add assert_greater compatibility function.
Fix tests to work with nose < 1.1.3. Compatibility functions borrowed from scikit-learn.
2012-09-13 22:17:24 -04:00

40 lines
1.2 KiB
Python

import numpy as np
from numpy.testing import assert_equal, assert_array_equal
from skimage._shared.testing import assert_greater
from skimage.segmentation import felzenszwalb
def test_grey():
# very weak tests. This algorithm is pretty unstable.
img = np.zeros((20, 21))
img[:10, 10:] = 0.2
img[10:, :10] = 0.4
img[10:, 10:] = 0.6
seg = felzenszwalb(img, sigma=0)
# we expect 4 segments:
assert_equal(len(np.unique(seg)), 4)
# that mostly respect the 4 regions:
for i in range(4):
hist = np.histogram(img[seg == i], bins=[0, 0.1, 0.3, 0.5, 1])[0]
assert_greater(hist[i], 40)
def test_color():
# very weak tests. This algorithm is pretty unstable.
img = np.zeros((20, 21, 3))
img[:10, :10, 0] = 1
img[10:, :10, 1] = 1
img[10:, 10:, 2] = 1
seg = felzenszwalb(img, sigma=0)
# we expect 4 segments:
assert_equal(len(np.unique(seg)), 4)
assert_array_equal(seg[:10, :10], 0)
assert_array_equal(seg[10:, :10], 2)
assert_array_equal(seg[:10, 10:], 1)
assert_array_equal(seg[10:, 10:], 3)
if __name__ == '__main__':
from numpy import testing
testing.run_module_suite()