76 lines
1.9 KiB
Python
76 lines
1.9 KiB
Python
from tempfile import NamedTemporaryFile
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import numpy as np
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from skimage import io
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from skimage.io import imread, imsave, use_plugin, reset_plugins
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from skimage._shared import testing
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from skimage._shared.testing import (
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TestCase,
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assert_array_equal,
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assert_array_almost_equal,
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fetch,
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)
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import pytest
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pytest.importorskip('imread')
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@pytest.fixture(autouse=True)
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def _use_imread_plugin():
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"""Ensure that PIL plugin is used in tests here."""
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use_plugin('imread')
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yield
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reset_plugins()
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def test_imread_as_gray():
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img = imread(fetch('data/color.png'), as_gray=True)
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assert img.ndim == 2
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assert img.dtype == np.float64
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img = imread(fetch('data/camera.png'), as_gray=True)
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# check that conversion does not happen for a gray image
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assert np.dtype(img.dtype).char in np.typecodes['AllInteger']
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def test_imread_palette():
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img = imread(fetch('data/palette_color.png'))
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assert img.ndim == 3
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def test_imread_truncated_jpg():
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with testing.raises(RuntimeError):
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io.imread(fetch('data/truncated.jpg'))
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def test_bilevel():
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expected = np.zeros((10, 10), bool)
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expected[::2] = 1
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img = imread(fetch('data/checker_bilevel.png'))
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assert_array_equal(img.astype(bool), expected)
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class TestSave(TestCase):
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def roundtrip(self, x, scaling=1):
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with NamedTemporaryFile(suffix='.png') as f:
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fname = f.name
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imsave(fname, x)
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y = imread(fname)
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assert_array_almost_equal((x * scaling).astype(np.int32), y)
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def test_imsave_roundtrip(self):
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dtype = np.uint8
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np.random.seed(0)
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for shape in [(10, 10), (10, 10, 3), (10, 10, 4)]:
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x = np.ones(shape, dtype=dtype) * np.random.rand(*shape)
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if np.issubdtype(dtype, np.floating):
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yield self.roundtrip, x, 255
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else:
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x = (x * 255).astype(dtype)
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yield self.roundtrip, x
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