def test_isodata_linspace(self):
image = cp.linspace(-127, 0, 256)
assert -63.8 < threshold_isodata(image) < -63.6
assert_array_almost_equal(
threshold_isodata(image, return_all=True),
[-63.74804688, -63.25195312],
)
def test_isodata_camera_image():
camera = util.img_as_ubyte(camerad)
threshold = threshold_isodata(camera)
assert (cp.floor((camera[camera <= threshold].mean() +
camera[camera > threshold].mean()) / 2.0) == threshold)
assert threshold == 87
assert_array_equal(threshold_isodata(camera, return_all=True), [87])
def test_isodata_coins_image():
coins = util.img_as_ubyte(coinsd)
threshold = threshold_isodata(coins)
assert (cp.floor(
(coins[coins <= threshold].mean() + coins[coins > threshold].mean()) /
2.0) == threshold)
assert threshold == 107
assert_array_equal(threshold_isodata(coins, return_all=True), [107])
def test_isodata_moon_image():
moon = util.img_as_ubyte(moond)
threshold = threshold_isodata(moon)
assert (cp.floor(
(moon[moon <= threshold].mean() + moon[moon > threshold].mean()) /
2.0) == threshold)
assert threshold == 86
thresholds = threshold_isodata(moon, return_all=True)
for threshold in thresholds:
assert (cp.floor(
(moon[moon <= threshold].mean() + moon[moon > threshold].mean()) /
2.0) == threshold)
assert_array_equal(thresholds, [86, 87, 88, 122, 123, 124, 139, 140])
def test_isodata_moon_image_negative_int():
moon = util.img_as_ubyte(moond).astype(cp.int32)
moon -= 100
threshold = threshold_isodata(moon)
assert (cp.floor(
(moon[moon <= threshold].mean() + moon[moon > threshold].mean()) /
2.0) == threshold)
assert threshold == -14
thresholds = threshold_isodata(moon, return_all=True)
for threshold in thresholds:
assert (cp.floor(
(moon[moon <= threshold].mean() + moon[moon > threshold].mean()) /
2.0) == threshold)
assert_array_equal(thresholds, [-14, -13, -12, 22, 23, 24, 39, 40])
def test_isodata_moon_image_negative_float():
moon = util.img_as_ubyte(moond).astype(cp.float64)
moon -= 100
assert -14 < threshold_isodata(moon) < -13
thresholds = threshold_isodata(moon, return_all=True)
# fmt: off
assert_array_almost_equal(
thresholds,
[
-13.83789062,
-12.84179688,
-11.84570312,
22.02148438, # noqa
23.01757812,
24.01367188,
38.95507812,
39.95117188
]) # noqa
def test_isodata_16bit(self):
np.random.seed(0)
imfloat = cp.asarray(np.random.rand(256, 256))
assert 0.49 < threshold_isodata(imfloat, nbins=1024) < 0.51
assert all(
0.49 < threshold_isodata(imfloat, nbins=1024, return_all=True))
def test_isodata_blank_zero(self):
image = cp.zeros((5, 5), dtype=cp.uint8)
assert threshold_isodata(image) == 0
assert_array_equal(threshold_isodata(image, return_all=True), [0])
def test_isodata(self):
assert threshold_isodata(self.image) == 2
assert_array_equal(threshold_isodata(self.image, return_all=True), [2])