Pillow

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from __future__ import annotations
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import pytest
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from .helper import assert_image_equal, hopper
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def test_sanity() -> None:
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    im = hopper()
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    with pytest.raises(ValueError):
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        im.point(list(range(256)))
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    im.point(list(range(256)) * 3)
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    im.point(lambda x: x)
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    im.point(lambda x: x * 1.2)
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    im = im.convert("I")
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    with pytest.raises(ValueError):
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        im.point(list(range(256)))
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    im.point(lambda x: x * 1)
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    im.point(lambda x: x + 1)
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    im.point(lambda x: x - 1)
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    im.point(lambda x: x * 1 + 1)
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    im.point(lambda x: 0.1 + 0.2 * x)
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    im.point(lambda x: -x)
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    im.point(lambda x: x - 0.5)
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    im.point(lambda x: 1 - x / 2)
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    im.point(lambda x: (2 + x) / 3)
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    im.point(lambda x: 0.5)
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    im.point(lambda x: x / 1)
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    im.point(lambda x: x + x)
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    with pytest.raises(TypeError):
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        im.point(lambda x: x * x)
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    with pytest.raises(TypeError):
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        im.point(lambda x: x / x)
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    with pytest.raises(TypeError):
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        im.point(lambda x: 1 / x)
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    with pytest.raises(TypeError):
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        im.point(lambda x: x // 2)
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def test_16bit_lut() -> None:
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    """Tests for 16 bit -> 8 bit lut for converting I->L images
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    see https://github.com/python-pillow/Pillow/issues/440
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    """
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    im = hopper("I")
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    im.point(list(range(256)) * 256, "L")
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def test_f_lut() -> None:
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    """Tests for floating point lut of 8bit gray image"""
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    im = hopper("L")
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    lut = [0.5 * float(x) for x in range(256)]
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    out = im.point(lut, "F")
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    int_lut = [x // 2 for x in range(256)]
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    assert_image_equal(out.convert("L"), im.point(int_lut, "L"))
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def test_f_mode() -> None:
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    im = hopper("F")
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    with pytest.raises(ValueError):
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        im.point([])
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