CofeehousePy/deps/scikit-image/skimage/transform/tests/test_pyramids.py

148 lines
5.5 KiB
Python

import math
import pytest
import numpy as np
from skimage import data
from skimage.transform import pyramids
from skimage._shared import testing
from skimage._shared.testing import (assert_array_equal, assert_, assert_equal,
assert_almost_equal)
image = data.astronaut()
image_gray = image[..., 0]
def test_pyramid_reduce_rgb():
rows, cols, dim = image.shape
out = pyramids.pyramid_reduce(image, downscale=2, multichannel=True)
assert_array_equal(out.shape, (rows / 2, cols / 2, dim))
def test_pyramid_reduce_gray():
rows, cols = image_gray.shape
out1 = pyramids.pyramid_reduce(image_gray, downscale=2,
multichannel=False)
assert_array_equal(out1.shape, (rows / 2, cols / 2))
assert_almost_equal(out1.ptp(), 1.0, decimal=2)
out2 = pyramids.pyramid_reduce(image_gray, downscale=2,
multichannel=False, preserve_range=True)
assert_almost_equal(out2.ptp() / image_gray.ptp(), 1.0, decimal=2)
def test_pyramid_reduce_nd():
for ndim in [1, 2, 3, 4]:
img = np.random.randn(*((8, ) * ndim))
out = pyramids.pyramid_reduce(img, downscale=2,
multichannel=False)
expected_shape = np.asarray(img.shape) / 2
assert_array_equal(out.shape, expected_shape)
def test_pyramid_expand_rgb():
rows, cols, dim = image.shape
out = pyramids.pyramid_expand(image, upscale=2,
multichannel=True)
assert_array_equal(out.shape, (rows * 2, cols * 2, dim))
def test_pyramid_expand_gray():
rows, cols = image_gray.shape
out = pyramids.pyramid_expand(image_gray, upscale=2,
multichannel=False)
assert_array_equal(out.shape, (rows * 2, cols * 2))
def test_pyramid_expand_nd():
for ndim in [1, 2, 3, 4]:
img = np.random.randn(*((4, ) * ndim))
out = pyramids.pyramid_expand(img, upscale=2,
multichannel=False)
expected_shape = np.asarray(img.shape) * 2
assert_array_equal(out.shape, expected_shape)
def test_build_gaussian_pyramid_rgb():
rows, cols, dim = image.shape
pyramid = pyramids.pyramid_gaussian(image, downscale=2,
multichannel=True)
for layer, out in enumerate(pyramid):
layer_shape = (rows / 2 ** layer, cols / 2 ** layer, dim)
assert_array_equal(out.shape, layer_shape)
def test_build_gaussian_pyramid_gray():
rows, cols = image_gray.shape
pyramid = pyramids.pyramid_gaussian(image_gray, downscale=2,
multichannel=False)
for layer, out in enumerate(pyramid):
layer_shape = (rows / 2 ** layer, cols / 2 ** layer)
assert_array_equal(out.shape, layer_shape)
def test_build_gaussian_pyramid_nd():
for ndim in [1, 2, 3, 4]:
img = np.random.randn(*((8, ) * ndim))
original_shape = np.asarray(img.shape)
pyramid = pyramids.pyramid_gaussian(img, downscale=2,
multichannel=False)
for layer, out in enumerate(pyramid):
layer_shape = original_shape / 2 ** layer
assert_array_equal(out.shape, layer_shape)
def test_build_laplacian_pyramid_rgb():
rows, cols, dim = image.shape
pyramid = pyramids.pyramid_laplacian(image, downscale=2,
multichannel=True)
for layer, out in enumerate(pyramid):
layer_shape = (rows / 2 ** layer, cols / 2 ** layer, dim)
assert_array_equal(out.shape, layer_shape)
def test_build_laplacian_pyramid_nd():
for ndim in [1, 2, 3, 4]:
img = np.random.randn(*(16, )*ndim)
original_shape = np.asarray(img.shape)
pyramid = pyramids.pyramid_laplacian(img, downscale=2,
multichannel=False)
for layer, out in enumerate(pyramid):
print(out.shape)
layer_shape = original_shape / 2 ** layer
assert_array_equal(out.shape, layer_shape)
def test_laplacian_pyramid_max_layers():
for downscale in [2, 3, 5, 7]:
img = np.random.randn(32, 8)
pyramid = pyramids.pyramid_laplacian(img, downscale=downscale,
multichannel=False)
max_layer = int(np.ceil(math.log(np.max(img.shape), downscale)))
for layer, out in enumerate(pyramid):
if layer < max_layer:
# should not reach all axes as size 1 prior to final level
assert_(np.max(out.shape) > 1)
# total number of images is max_layer + 1
assert_equal(max_layer, layer)
# final layer should be size 1 on all axes
assert_array_equal((out.shape), (1, 1))
def test_check_factor():
with testing.raises(ValueError):
pyramids._check_factor(0.99)
with testing.raises(ValueError):
pyramids._check_factor(- 2)
@pytest.mark.parametrize('dtype, expected',
zip(['float32', 'float64', 'uint8', 'int64'],
['float32', 'float64', 'float64', 'float64']))
def test_pyramid_gaussian_dtype_support(dtype, expected):
img = np.random.randn(32, 8).astype(dtype)
pyramid = pyramids.pyramid_gaussian(img)
assert np.all([im.dtype == expected for im in pyramid])