CofeehousePy/deps/scikit-image/skimage/util/tests/test_apply_parallel.py

114 lines
3.6 KiB
Python

import numpy as np
from skimage._shared.testing import assert_array_almost_equal, assert_equal
from skimage import color, data
from skimage.filters import threshold_local, gaussian
from skimage.util.apply_parallel import apply_parallel
import pytest
da = pytest.importorskip('dask.array')
def test_apply_parallel():
# data
a = np.arange(144).reshape(12, 12).astype(float)
# apply the filter
expected1 = threshold_local(a, 3)
result1 = apply_parallel(threshold_local, a, chunks=(6, 6), depth=5,
extra_arguments=(3,),
extra_keywords={'mode': 'reflect'})
assert_array_almost_equal(result1, expected1)
def wrapped_gauss(arr):
return gaussian(arr, 1, mode='reflect')
expected2 = gaussian(a, 1, mode='reflect')
result2 = apply_parallel(wrapped_gauss, a, chunks=(6, 6), depth=5)
assert_array_almost_equal(result2, expected2)
expected3 = gaussian(a, 1, mode='reflect')
result3 = apply_parallel(
wrapped_gauss, da.from_array(a, chunks=(6, 6)), depth=5, compute=True
)
assert isinstance(result3, np.ndarray)
assert_array_almost_equal(result3, expected3)
def test_apply_parallel_lazy():
# data
a = np.arange(144).reshape(12, 12).astype(float)
d = da.from_array(a, chunks=(6, 6))
# apply the filter
expected1 = threshold_local(a, 3)
result1 = apply_parallel(threshold_local, a, chunks=(6, 6), depth=5,
extra_arguments=(3,),
extra_keywords={'mode': 'reflect'},
compute=False)
# apply the filter on a Dask Array
result2 = apply_parallel(threshold_local, d, depth=5,
extra_arguments=(3,),
extra_keywords={'mode': 'reflect'})
assert isinstance(result1, da.Array)
assert_array_almost_equal(result1.compute(), expected1)
assert isinstance(result2, da.Array)
assert_array_almost_equal(result2.compute(), expected1)
def test_no_chunks():
a = np.ones(1 * 4 * 8 * 9).reshape(1, 4, 8, 9)
def add_42(arr):
return arr + 42
expected = add_42(a)
result = apply_parallel(add_42, a)
assert_array_almost_equal(result, expected)
def test_apply_parallel_wrap():
def wrapped(arr):
return gaussian(arr, 1, mode='wrap')
a = np.arange(144).reshape(12, 12).astype(float)
expected = gaussian(a, 1, mode='wrap')
result = apply_parallel(wrapped, a, chunks=(6, 6), depth=5, mode='wrap')
assert_array_almost_equal(result, expected)
def test_apply_parallel_nearest():
def wrapped(arr):
return gaussian(arr, 1, mode='nearest')
a = np.arange(144).reshape(12, 12).astype(float)
expected = gaussian(a, 1, mode='nearest')
result = apply_parallel(wrapped, a, chunks=(6, 6), depth={0: 5, 1: 5},
mode='nearest')
assert_array_almost_equal(result, expected)
@pytest.mark.parametrize('dtype', (np.float32, np.float64))
@pytest.mark.parametrize('chunks', (None, (128, 128, 3)))
@pytest.mark.parametrize('depth', (0, 8, (8, 8, 0)))
def test_apply_parallel_rgb(depth, chunks, dtype):
cat = data.chelsea().astype(dtype) / 255.
func = color.rgb2ycbcr
cat_ycbcr_expected = func(cat)
cat_ycbcr = apply_parallel(func, cat, chunks=chunks, depth=depth,
dtype=dtype, multichannel=True)
assert_equal(cat_ycbcr.dtype, cat.dtype)
assert_array_almost_equal(cat_ycbcr_expected, cat_ycbcr)