Pillow/Tests/test_image_convert.py

from .helper import PillowTestCase, hopper

from PIL import Image


class TestImageConvert(PillowTestCase):

    def test_sanity(self):

        def convert(im, mode):
            out = im.convert(mode)
            self.assertEqual(out.mode, mode)
            self.assertEqual(out.size, im.size)

        modes = ("1", "L", "LA", "P", "PA", "I", "F",
                 "RGB", "RGBA", "RGBX", "CMYK", "YCbCr")

        for mode in modes:
            im = hopper(mode)
            for mode in modes:
                convert(im, mode)

            # Check 0
            im = Image.new(mode, (0, 0))
            for mode in modes:
                convert(im, mode)

    def test_default(self):

        im = hopper("P")
        self.assert_image(im, "P", im.size)
        im = im.convert()
        self.assert_image(im, "RGB", im.size)
        im = im.convert()
        self.assert_image(im, "RGB", im.size)

    # ref https://github.com/python-pillow/Pillow/issues/274

    def _test_float_conversion(self, im):
        orig = im.getpixel((5, 5))
        converted = im.convert('F').getpixel((5, 5))
        self.assertEqual(orig, converted)

    def test_8bit(self):
        im = Image.open('Tests/images/hopper.jpg')
        self._test_float_conversion(im.convert('L'))

    def test_16bit(self):
        im = Image.open('Tests/images/16bit.cropped.tif')
        self._test_float_conversion(im)

    def test_16bit_workaround(self):
        im = Image.open('Tests/images/16bit.cropped.tif')
        self._test_float_conversion(im.convert('I'))

    def test_rgba_p(self):
        im = hopper('RGBA')
        im.putalpha(hopper('L'))

        converted = im.convert('P')
        comparable = converted.convert('RGBA')

        self.assert_image_similar(im, comparable, 20)

    def test_trns_p(self):
        im = hopper('P')
        im.info['transparency'] = 0

        f = self.tempfile('temp.png')

        im_l = im.convert('L')
        self.assertEqual(im_l.info['transparency'], 0)  # undone
        im_l.save(f)

        im_rgb = im.convert('RGB')
        self.assertEqual(im_rgb.info['transparency'], (0, 0, 0))  # undone
        im_rgb.save(f)

    # ref https://github.com/python-pillow/Pillow/issues/664

    def test_trns_p_rgba(self):
        # Arrange
        im = hopper('P')
        im.info['transparency'] = 128

        # Act
        im_rgba = im.convert('RGBA')

        # Assert
        self.assertNotIn('transparency', im_rgba.info)
        # https://github.com/python-pillow/Pillow/issues/2702
        self.assertIsNone(im_rgba.palette)

    def test_trns_l(self):
        im = hopper('L')
        im.info['transparency'] = 128

        f = self.tempfile('temp.png')

        im_rgb = im.convert('RGB')
        self.assertEqual(im_rgb.info['transparency'],
                         (128, 128, 128))  # undone
        im_rgb.save(f)

        im_p = im.convert('P')
        self.assertIn('transparency', im_p.info)
        im_p.save(f)

        im_p = self.assert_warning(
            UserWarning,
            im.convert, 'P', palette=Image.ADAPTIVE)
        self.assertNotIn('transparency', im_p.info)
        im_p.save(f)

    def test_trns_RGB(self):
        im = hopper('RGB')
        im.info['transparency'] = im.getpixel((0, 0))

        f = self.tempfile('temp.png')

        im_l = im.convert('L')
        self.assertEqual(im_l.info['transparency'],
                         im_l.getpixel((0, 0)))  # undone
        im_l.save(f)

        im_p = im.convert('P')
        self.assertIn('transparency', im_p.info)
        im_p.save(f)

        im_rgba = im.convert('RGBA')
        self.assertNotIn('transparency', im_rgba.info)
        im_rgba.save(f)

        im_p = self.assert_warning(
            UserWarning,
            im.convert, 'P', palette=Image.ADAPTIVE)
        self.assertNotIn('transparency', im_p.info)
        im_p.save(f)

    def test_gif_with_rgba_palette_to_p(self):
        # See https://github.com/python-pillow/Pillow/issues/2433
        im = Image.open('Tests/images/hopper.gif')
        im.info['transparency'] = 255
        im.load()
        self.assertEqual(im.palette.mode, 'RGBA')
        im_p = im.convert('P')

        # Should not raise ValueError: unrecognized raw mode
        im_p.load()

    def test_p_la(self):
        im = hopper('RGBA')
        alpha = hopper('L')
        im.putalpha(alpha)

        comparable = im.convert('P').convert('LA').getchannel('A')

        self.assert_image_similar(alpha, comparable, 5)

    def test_matrix_illegal_conversion(self):
        # Arrange
        im = hopper('CMYK')
        matrix = (
            0.412453, 0.357580, 0.180423, 0,
            0.212671, 0.715160, 0.072169, 0,
            0.019334, 0.119193, 0.950227, 0)
        self.assertNotEqual(im.mode, 'RGB')

        # Act / Assert
        self.assertRaises(ValueError,
                          im.convert, mode='CMYK', matrix=matrix)

    def test_matrix_wrong_mode(self):
        # Arrange
        im = hopper('L')
        matrix = (
            0.412453, 0.357580, 0.180423, 0,
            0.212671, 0.715160, 0.072169, 0,
            0.019334, 0.119193, 0.950227, 0)
        self.assertEqual(im.mode, 'L')

        # Act / Assert
        self.assertRaises(ValueError,
                          im.convert, mode='L', matrix=matrix)

    def test_matrix_xyz(self):

        def matrix_convert(mode):
            # Arrange
            im = hopper('RGB')
            im.info['transparency'] = (255, 0, 0)
            matrix = (
                0.412453, 0.357580, 0.180423, 0,
                0.212671, 0.715160, 0.072169, 0,
                0.019334, 0.119193, 0.950227, 0)
            self.assertEqual(im.mode, 'RGB')

            # Act
            # Convert an RGB image to the CIE XYZ colour space
            converted_im = im.convert(mode=mode, matrix=matrix)

            # Assert
            self.assertEqual(converted_im.mode, mode)
            self.assertEqual(converted_im.size, im.size)
            target = Image.open('Tests/images/hopper-XYZ.png')
            if converted_im.mode == 'RGB':
                self.assert_image_similar(converted_im, target, 3)
                self.assertEqual(converted_im.info['transparency'],
                                 (105, 54, 4))
            else:
                self.assert_image_similar(converted_im,
                                          target.getchannel(0), 1)
                self.assertEqual(converted_im.info['transparency'], 105)

        matrix_convert('RGB')
        matrix_convert('L')

    def test_matrix_identity(self):
        # Arrange
        im = hopper('RGB')
        identity_matrix = (
            1, 0, 0, 0,
            0, 1, 0, 0,
            0, 0, 1, 0)
        self.assertEqual(im.mode, 'RGB')

        # Act
        # Convert with an identity matrix
        converted_im = im.convert(mode='RGB', matrix=identity_matrix)

        # Assert
        # No change
        self.assert_image_equal(converted_im, im)