Pillow/Tests/test_imagepalette.py

from .helper import PillowTestCase

from PIL import ImagePalette, Image


class TestImagePalette(PillowTestCase):

    def test_sanity(self):

        ImagePalette.ImagePalette("RGB", list(range(256))*3)
        self.assertRaises(ValueError,
                          ImagePalette.ImagePalette, "RGB", list(range(256))*2)

    def test_getcolor(self):

        palette = ImagePalette.ImagePalette()

        test_map = {}
        for i in range(256):
            test_map[palette.getcolor((i, i, i))] = i

        self.assertEqual(len(test_map), 256)
        self.assertRaises(ValueError, palette.getcolor, (1, 2, 3))

        # Test unknown color specifier
        self.assertRaises(ValueError, palette.getcolor, "unknown")

    def test_file(self):

        palette = ImagePalette.ImagePalette("RGB", list(range(256))*3)

        f = self.tempfile("temp.lut")

        palette.save(f)

        p = ImagePalette.load(f)

        # load returns raw palette information
        self.assertEqual(len(p[0]), 768)
        self.assertEqual(p[1], "RGB")

        p = ImagePalette.raw(p[1], p[0])
        self.assertIsInstance(p, ImagePalette.ImagePalette)
        self.assertEqual(p.palette, palette.tobytes())

    def test_make_linear_lut(self):
        # Arrange
        black = 0
        white = 255

        # Act
        lut = ImagePalette.make_linear_lut(black, white)

        # Assert
        self.assertIsInstance(lut, list)
        self.assertEqual(len(lut), 256)
        # Check values
        for i in range(0, len(lut)):
            self.assertEqual(lut[i], i)

    def test_make_linear_lut_not_yet_implemented(self):
        # Update after FIXME
        # Arrange
        black = 1
        white = 255

        # Act
        self.assertRaises(NotImplementedError,
                          ImagePalette.make_linear_lut, black, white)

    def test_make_gamma_lut(self):
        # Arrange
        exp = 5

        # Act
        lut = ImagePalette.make_gamma_lut(exp)

        # Assert
        self.assertIsInstance(lut, list)
        self.assertEqual(len(lut), 256)
        # Check a few values
        self.assertEqual(lut[0], 0)
        self.assertEqual(lut[63], 0)
        self.assertEqual(lut[127], 8)
        self.assertEqual(lut[191], 60)
        self.assertEqual(lut[255], 255)

    def test_rawmode_valueerrors(self):
        # Arrange
        palette = ImagePalette.raw("RGB", list(range(256))*3)

        # Act / Assert
        self.assertRaises(ValueError, palette.tobytes)
        self.assertRaises(ValueError, palette.getcolor, (1, 2, 3))
        f = self.tempfile("temp.lut")
        self.assertRaises(ValueError, palette.save, f)

    def test_getdata(self):
        # Arrange
        data_in = list(range(256))*3
        palette = ImagePalette.ImagePalette("RGB", data_in)

        # Act
        mode, data_out = palette.getdata()

        # Assert
        self.assertEqual(mode, "RGB;L")

    def test_rawmode_getdata(self):
        # Arrange
        data_in = list(range(256))*3
        palette = ImagePalette.raw("RGB", data_in)

        # Act
        rawmode, data_out = palette.getdata()

        # Assert
        self.assertEqual(rawmode, "RGB")
        self.assertEqual(data_in, data_out)

    def test_2bit_palette(self):
        # issue #2258, 2 bit palettes are corrupted.
        outfile = self.tempfile('temp.png')

        rgb = b'\x00' * 2 + b'\x01' * 2 + b'\x02' * 2
        img = Image.frombytes('P', (6, 1), rgb)
        img.putpalette(b'\xFF\x00\x00\x00\xFF\x00\x00\x00\xFF')  # RGB
        img.save(outfile, format='PNG')

        reloaded = Image.open(outfile)

        self.assert_image_equal(img, reloaded)

    def test_invalid_palette(self):
        self.assertRaises(IOError,
                          ImagePalette.load, "Tests/images/hopper.jpg")