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jklymakjklymak
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Merge pull request #10335 from anntzer/parametrize-image-comparison
Update some image_comparison tests.
2 parents 090e9f1 + bbbfef6 commit c09f726

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‎lib/matplotlib/tests/test_backend_pgf.py

+7-7
Original file line numberDiff line numberDiff line change
@@ -11,7 +11,7 @@
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import matplotlib.pyplot as plt
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from matplotlib.compat import subprocess
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from matplotlib.testing.compare import compare_images, ImageComparisonFailure
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from matplotlib.testing.decorators import _image_directories
14+
from matplotlib.testing.decorators import image_comparison, _image_directories
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baseline_dir, result_dir = _image_directories(lambda: 'dummy func')
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@@ -81,20 +81,21 @@ def create_figure():
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# test compiling a figure to pdf with xelatex
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@needs_xelatex
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@pytest.mark.style('default')
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@pytest.mark.backend('pgf')
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@image_comparison(baseline_images=['pgf_xelatex'], extensions=['pdf'],
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style='default')
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def test_xelatex():
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rc_xelatex = {'font.family': 'serif',
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'pgf.rcfonts': False}
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mpl.rcParams.update(rc_xelatex)
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create_figure()
91-
compare_figure('pgf_xelatex.pdf', tol=0)
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# test compiling a figure to pdf with pdflatex
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@needs_pdflatex
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@pytest.mark.style('default')
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@pytest.mark.backend('pgf')
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@image_comparison(baseline_images=['pgf_pdflatex'], extensions=['pdf'],
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style='default')
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def test_pdflatex():
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import os
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if os.environ.get('APPVEYOR', False):
@@ -108,7 +109,6 @@ def test_pdflatex():
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'\\usepackage[T1]{fontenc}']}
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mpl.rcParams.update(rc_pdflatex)
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create_figure()
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compare_figure('pgf_pdflatex.pdf', tol=0)
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# test updating the rc parameters for each figure
@@ -162,8 +162,9 @@ def test_pathclip():
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# test mixed mode rendering
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@needs_xelatex
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@pytest.mark.style('default')
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@pytest.mark.backend('pgf')
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@image_comparison(baseline_images=['pgf_mixedmode'], extensions=['pdf'],
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style='default')
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def test_mixedmode():
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rc_xelatex = {'font.family': 'serif',
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'pgf.rcfonts': False}
@@ -172,7 +173,6 @@ def test_mixedmode():
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Y, X = np.ogrid[-1:1:40j, -1:1:40j]
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plt.figure()
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plt.pcolor(X**2 + Y**2).set_rasterized(True)
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compare_figure('pgf_mixedmode.pdf', tol=0)
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# test bbox_inches clipping

‎lib/matplotlib/tests/test_compare_images.py

+37-62
Original file line numberDiff line numberDiff line change
@@ -9,6 +9,7 @@
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from numpy.testing import assert_almost_equal
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import pytest
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from pytest import approx
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from matplotlib.testing.compare import compare_images
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from matplotlib.testing.decorators import _image_directories, image_comparison
@@ -19,7 +20,40 @@
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# Tests of the image comparison algorithm.
22-
def image_comparison_expect_rms(im1, im2, tol, expect_rms):
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@pytest.mark.parametrize(
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'im1, im2, tol, expect_rms',
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[
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# Comparison of an image and the same image with minor differences.
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# This expects the images to compare equal under normal tolerance, and
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# have a small RMS.
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('basn3p02.png', 'basn3p02-minorchange.png', 10, None),
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# Now test with no tolerance.
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('basn3p02.png', 'basn3p02-minorchange.png', 0, 6.50646),
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# Comparison with an image that is shifted by 1px in the X axis.
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('basn3p02.png', 'basn3p02-1px-offset.png', 0, 90.15611),
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# Comparison with an image with half the pixels shifted by 1px in the X
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# axis.
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('basn3p02.png', 'basn3p02-half-1px-offset.png', 0, 63.75),
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# Comparison of an image and the same image scrambled.
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# This expects the images to compare completely different, with a very
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# large RMS.
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# Note: The image has been scrambled in a specific way, by having
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# each color component of each pixel randomly placed somewhere in the
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# image. It contains exactly the same number of pixels of each color
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# value of R, G and B, but in a totally different position.
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# Test with no tolerance to make sure that we pick up even a very small
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# RMS error.
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('basn3p02.png', 'basn3p02-scrambled.png', 0, 172.63582),
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# Comparison of an image and a slightly brighter image.
48+
# The two images are solid color, with the second image being exactly 1
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# color value brighter.
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# This expects the images to compare equal under normal tolerance, and
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# have an RMS of exactly 1.
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('all127.png', 'all128.png', 0, 1),
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# Now test the reverse comparison.
54+
('all128.png', 'all127.png', 0, 1),
55+
])
56+
def test_image_comparison_expect_rms(im1, im2, tol, expect_rms):
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"""Compare two images, expecting a particular RMS error.
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2559
im1 and im2 are filenames relative to the baseline_dir directory.
@@ -43,72 +77,13 @@ def image_comparison_expect_rms(im1, im2, tol, expect_rms):
4377
assert results is None
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else:
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assert results is not None
46-
assert_almost_equal(expect_rms, results['rms'], decimal=4)
47-
48-
49-
def test_image_compare_basic():
50-
#: Test comparison of an image and the same image with minor differences.
51-
52-
# This expects the images to compare equal under normal tolerance, and have
53-
# a small RMS.
54-
im1 = 'basn3p02.png'
55-
im2 = 'basn3p02-minorchange.png'
56-
image_comparison_expect_rms(im1, im2, tol=10, expect_rms=None)
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# Now test with no tolerance.
59-
image_comparison_expect_rms(im1, im2, tol=0, expect_rms=6.50646)
60-
61-
62-
def test_image_compare_1px_offset():
63-
#: Test comparison with an image that is shifted by 1px in the X axis.
64-
im1 = 'basn3p02.png'
65-
im2 = 'basn3p02-1px-offset.png'
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image_comparison_expect_rms(im1, im2, tol=0, expect_rms=90.15611)
80+
assert results['rms'] == approx(expect_rms, abs=1e-4)
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69-
def test_image_compare_half_1px_offset():
70-
#: Test comparison with an image with half the pixels shifted by 1px in
71-
#: the X axis.
72-
im1 = 'basn3p02.png'
73-
im2 = 'basn3p02-half-1px-offset.png'
74-
image_comparison_expect_rms(im1, im2, tol=0, expect_rms=63.75)
75-
76-
77-
def test_image_compare_scrambled():
78-
#: Test comparison of an image and the same image scrambled.
79-
80-
# This expects the images to compare completely different, with a very
81-
# large RMS.
82-
# Note: The image has been scrambled in a specific way, by having each
83-
# color component of each pixel randomly placed somewhere in the image. It
84-
# contains exactly the same number of pixels of each color value of R, G
85-
# and B, but in a totally different position.
86-
im1 = 'basn3p02.png'
87-
im2 = 'basn3p02-scrambled.png'
88-
# Test with no tolerance to make sure that we pick up even a very small RMS
89-
# error.
90-
image_comparison_expect_rms(im1, im2, tol=0, expect_rms=172.63582)
91-
92-
93-
def test_image_compare_shade_difference():
94-
#: Test comparison of an image and a slightly brighter image.
95-
# The two images are solid color, with the second image being exactly 1
96-
# color value brighter.
97-
# This expects the images to compare equal under normal tolerance, and have
98-
# an RMS of exactly 1.
99-
im1 = 'all127.png'
100-
im2 = 'all128.png'
101-
image_comparison_expect_rms(im1, im2, tol=0, expect_rms=1.0)
102-
103-
# Now test the reverse comparison.
104-
image_comparison_expect_rms(im2, im1, tol=0, expect_rms=1.0)
105-
106-
107-
#
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# The following tests are used by test_nose_image_comparison to ensure that the
10984
# image_comparison decorator continues to work with nose. They should not be
11085
# prefixed by test_ so they don't run with pytest.
111-
#
86+
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11388
def nosetest_empty():
11489
pass

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