Pillow/Tests/test_image_point.py

from .helper import PillowTestCase, hopper


class TestImagePoint(PillowTestCase):
    def test_sanity(self):
        im = hopper()

        self.assertRaises(ValueError, im.point, list(range(256)))
        im.point(list(range(256)) * 3)
        im.point(lambda x: x)

        im = im.convert("I")
        self.assertRaises(ValueError, im.point, list(range(256)))
        im.point(lambda x: x * 1)
        im.point(lambda x: x + 1)
        im.point(lambda x: x * 1 + 1)
        self.assertRaises(TypeError, im.point, lambda x: x - 1)
        self.assertRaises(TypeError, im.point, lambda x: x / 1)

    def test_16bit_lut(self):
        """ Tests for 16 bit -> 8 bit lut for converting I->L images
            see https://github.com/python-pillow/Pillow/issues/440
            """
        im = hopper("I")
        im.point(list(range(256)) * 256, "L")

    def test_f_lut(self):
        """ Tests for floating point lut of 8bit gray image """
        im = hopper("L")
        lut = [0.5 * float(x) for x in range(256)]

        out = im.point(lut, "F")

        int_lut = [x // 2 for x in range(256)]
        self.assert_image_equal(out.convert("L"), im.point(int_lut, "L"))

    def test_f_mode(self):
        im = hopper("F")
        self.assertRaises(ValueError, im.point, None)