Pillow/Tests/test_file_gif.py

from helper import unittest, PillowTestCase, tearDownModule, lena

from PIL import Image

codecs = dir(Image.core)

# sample gif stream
file = "Tests/images/lena.gif"
with open(file, "rb") as f:
    data = f.read()


class TestFileGif(PillowTestCase):

    def setUp(self):
        if "gif_encoder" not in codecs or "gif_decoder" not in codecs:
            self.skipTest("gif support not available")  # can this happen?

    def test_sanity(self):
        im = Image.open(file)
        im.load()
        self.assertEqual(im.mode, "P")
        self.assertEqual(im.size, (128, 128))
        self.assertEqual(im.format, "GIF")

    def test_optimize(self):
        from io import BytesIO

        def test(optimize):
            im = Image.new("L", (1, 1), 0)
            file = BytesIO()
            im.save(file, "GIF", optimize=optimize)
            return len(file.getvalue())
        self.assertEqual(test(0), 800)
        self.assertEqual(test(1), 38)

    def test_roundtrip(self):
        out = self.tempfile('temp.gif')
        im = lena()
        im.save(out)
        reread = Image.open(out)

        self.assert_image_similar(reread.convert('RGB'), im, 50)

    def test_roundtrip2(self):
        # see https://github.com/python-pillow/Pillow/issues/403
        out = self.tempfile('temp.gif')
        im = Image.open('Tests/images/lena.gif')
        im2 = im.copy()
        im2.save(out)
        reread = Image.open(out)

        self.assert_image_similar(reread.convert('RGB'), lena(), 50)

    def test_palette_handling(self):
        # see https://github.com/python-pillow/Pillow/issues/513

        im = Image.open('Tests/images/lena.gif')
        im = im.convert('RGB')

        im = im.resize((100, 100), Image.ANTIALIAS)
        im2 = im.convert('P', palette=Image.ADAPTIVE, colors=256)

        f = self.tempfile('temp.gif')
        im2.save(f, optimize=True)

        reloaded = Image.open(f)

        self.assert_image_similar(im, reloaded.convert('RGB'), 10)

    def test_palette_434(self):
        # see https://github.com/python-pillow/Pillow/issues/434

        def roundtrip(im, *args, **kwargs):
            out = self.tempfile('temp.gif')
            im.save(out, *args, **kwargs)
            reloaded = Image.open(out)

            return [im, reloaded]

        orig = "Tests/images/test.colors.gif"
        im = Image.open(orig)

        self.assert_image_equal(*roundtrip(im))
        self.assert_image_equal(*roundtrip(im, optimize=True))

        im = im.convert("RGB")
        # check automatic P conversion
        reloaded = roundtrip(im)[1].convert('RGB')
        self.assert_image_equal(im, reloaded)


if __name__ == '__main__':
    unittest.main()

# End of file