test_file_apng.py

from PIL import Image, ImageSequence, PngImagePlugin

import pytest

from .helper import PillowTestCase


class TestFilePng(PillowTestCase):

    # APNG browser support tests and fixtures via:
    # https://philip.html5.org/tests/apng/tests.html
    # (referenced from https://wiki.mozilla.org/APNG_Specification)
    def test_apng_basic(self):
        with Image.open("Tests/images/apng/single_frame.png") as im:
            self.assertFalse(im.is_animated)
            self.assertEqual(im.n_frames, 1)
            self.assertEqual(im.get_format_mimetype(), "image/apng")
            self.assertIsNone(im.info.get("default_image"))
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/single_frame_default.png") as im:
            self.assertTrue(im.is_animated)
            self.assertEqual(im.n_frames, 2)
            self.assertEqual(im.get_format_mimetype(), "image/apng")
            self.assertTrue(im.info.get("default_image"))
            self.assertEqual(im.getpixel((0, 0)), (255, 0, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (255, 0, 0, 255))
            im.seek(1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

            # test out of bounds seek
            with self.assertRaises(EOFError):
                im.seek(2)

            # test rewind support
            im.seek(0)
            self.assertEqual(im.getpixel((0, 0)), (255, 0, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (255, 0, 0, 255))
            im.seek(1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

    def test_apng_fdat(self):
        with Image.open("Tests/images/apng/split_fdat.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/split_fdat_zero_chunk.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

    def test_apng_dispose(self):
        with Image.open("Tests/images/apng/dispose_op_none.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/dispose_op_background.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 0, 0))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 0, 0))

        with Image.open("Tests/images/apng/dispose_op_background_final.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/dispose_op_previous.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/dispose_op_previous_final.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/dispose_op_previous_first.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 0, 0))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 0, 0))

    def test_apng_dispose_region(self):
        with Image.open("Tests/images/apng/dispose_op_none_region.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open(
            "Tests/images/apng/dispose_op_background_before_region.png"
        ) as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 0, 0))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 0, 0))

        with Image.open("Tests/images/apng/dispose_op_background_region.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 255, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 0, 0))

        with Image.open("Tests/images/apng/dispose_op_previous_region.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

    def test_apng_blend(self):
        with Image.open("Tests/images/apng/blend_op_source_solid.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/blend_op_source_transparent.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 0, 0))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 0, 0))

        with Image.open("Tests/images/apng/blend_op_source_near_transparent.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 2))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 2))

        with Image.open("Tests/images/apng/blend_op_over.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/blend_op_over_near_transparent.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 97))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

    def test_apng_chunk_order(self):
        with Image.open("Tests/images/apng/fctl_actl.png") as im:
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

    def test_apng_delay(self):
        with Image.open("Tests/images/apng/delay.png") as im:
            im.seek(1)
            self.assertEqual(im.info.get("duration"), 500.0)
            im.seek(2)
            self.assertEqual(im.info.get("duration"), 1000.0)
            im.seek(3)
            self.assertEqual(im.info.get("duration"), 500.0)
            im.seek(4)
            self.assertEqual(im.info.get("duration"), 1000.0)

        with Image.open("Tests/images/apng/delay_round.png") as im:
            im.seek(1)
            self.assertEqual(im.info.get("duration"), 500.0)
            im.seek(2)
            self.assertEqual(im.info.get("duration"), 1000.0)

        with Image.open("Tests/images/apng/delay_short_max.png") as im:
            im.seek(1)
            self.assertEqual(im.info.get("duration"), 500.0)
            im.seek(2)
            self.assertEqual(im.info.get("duration"), 1000.0)

        with Image.open("Tests/images/apng/delay_zero_denom.png") as im:
            im.seek(1)
            self.assertEqual(im.info.get("duration"), 500.0)
            im.seek(2)
            self.assertEqual(im.info.get("duration"), 1000.0)

        with Image.open("Tests/images/apng/delay_zero_numer.png") as im:
            im.seek(1)
            self.assertEqual(im.info.get("duration"), 0.0)
            im.seek(2)
            self.assertEqual(im.info.get("duration"), 0.0)
            im.seek(3)
            self.assertEqual(im.info.get("duration"), 500.0)
            im.seek(4)
            self.assertEqual(im.info.get("duration"), 1000.0)

    def test_apng_num_plays(self):
        with Image.open("Tests/images/apng/num_plays.png") as im:
            self.assertEqual(im.info.get("loop"), 0)

        with Image.open("Tests/images/apng/num_plays_1.png") as im:
            self.assertEqual(im.info.get("loop"), 1)

    def test_apng_mode(self):
        with Image.open("Tests/images/apng/mode_16bit.png") as im:
            self.assertEqual(im.mode, "RGBA")
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 128, 191))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 128, 191))

        with Image.open("Tests/images/apng/mode_greyscale.png") as im:
            self.assertEqual(im.mode, "L")
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), 128)
            self.assertEqual(im.getpixel((64, 32)), 255)

        with Image.open("Tests/images/apng/mode_greyscale_alpha.png") as im:
            self.assertEqual(im.mode, "LA")
            im.seek(im.n_frames - 1)
            self.assertEqual(im.getpixel((0, 0)), (128, 191))
            self.assertEqual(im.getpixel((64, 32)), (128, 191))

        with Image.open("Tests/images/apng/mode_palette.png") as im:
            self.assertEqual(im.mode, "P")
            im.seek(im.n_frames - 1)
            im = im.convert("RGB")
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0))

        with Image.open("Tests/images/apng/mode_palette_alpha.png") as im:
            self.assertEqual(im.mode, "P")
            im.seek(im.n_frames - 1)
            im = im.convert("RGBA")
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/mode_palette_1bit_alpha.png") as im:
            self.assertEqual(im.mode, "P")
            im.seek(im.n_frames - 1)
            im = im.convert("RGBA")
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 255, 128))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 255, 128))

    def test_apng_chunk_errors(self):
        with Image.open("Tests/images/apng/chunk_no_actl.png") as im:
            self.assertFalse(im.is_animated)

        def open():
            with Image.open("Tests/images/apng/chunk_multi_actl.png") as im:
                im.load()
            self.assertFalse(im.is_animated)

        pytest.warns(UserWarning, open)

        with Image.open("Tests/images/apng/chunk_actl_after_idat.png") as im:
            self.assertFalse(im.is_animated)

        with Image.open("Tests/images/apng/chunk_no_fctl.png") as im:
            with self.assertRaises(SyntaxError):
                im.seek(im.n_frames - 1)

        with Image.open("Tests/images/apng/chunk_repeat_fctl.png") as im:
            with self.assertRaises(SyntaxError):
                im.seek(im.n_frames - 1)

        with Image.open("Tests/images/apng/chunk_no_fdat.png") as im:
            with self.assertRaises(SyntaxError):
                im.seek(im.n_frames - 1)

    def test_apng_syntax_errors(self):
        def open_frames_zero():
            with Image.open("Tests/images/apng/syntax_num_frames_zero.png") as im:
                self.assertFalse(im.is_animated)
                with self.assertRaises(OSError):
                    im.load()

        pytest.warns(UserWarning, open_frames_zero)

        def open_frames_zero_default():
            with Image.open(
                "Tests/images/apng/syntax_num_frames_zero_default.png"
            ) as im:
                self.assertFalse(im.is_animated)
                im.load()

        pytest.warns(UserWarning, open_frames_zero_default)

        # we can handle this case gracefully
        exception = None
        with Image.open("Tests/images/apng/syntax_num_frames_low.png") as im:
            try:
                im.seek(im.n_frames - 1)
            except Exception as e:
                exception = e
            self.assertIsNone(exception)

        with self.assertRaises(SyntaxError):
            with Image.open("Tests/images/apng/syntax_num_frames_high.png") as im:
                im.seek(im.n_frames - 1)
                im.load()

        def open():
            with Image.open("Tests/images/apng/syntax_num_frames_invalid.png") as im:
                self.assertFalse(im.is_animated)
                im.load()

        pytest.warns(UserWarning, open)

    def test_apng_sequence_errors(self):
        test_files = [
            "sequence_start.png",
            "sequence_gap.png",
            "sequence_repeat.png",
            "sequence_repeat_chunk.png",
            "sequence_reorder.png",
            "sequence_reorder_chunk.png",
            "sequence_fdat_fctl.png",
        ]
        for f in test_files:
            with self.assertRaises(SyntaxError):
                with Image.open("Tests/images/apng/{0}".format(f)) as im:
                    im.seek(im.n_frames - 1)
                    im.load()

    def test_apng_save(self):
        with Image.open("Tests/images/apng/single_frame.png") as im:
            test_file = self.tempfile("temp.png")
            im.save(test_file, save_all=True)

        with Image.open(test_file) as im:
            im.load()
            self.assertFalse(im.is_animated)
            self.assertEqual(im.n_frames, 1)
            self.assertEqual(im.get_format_mimetype(), "image/apng")
            self.assertIsNone(im.info.get("default_image"))
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        with Image.open("Tests/images/apng/single_frame_default.png") as im:
            frames = []
            for frame_im in ImageSequence.Iterator(im):
                frames.append(frame_im.copy())
            frames[0].save(
                test_file, save_all=True, default_image=True, append_images=frames[1:]
            )

        with Image.open(test_file) as im:
            im.load()
            self.assertTrue(im.is_animated)
            self.assertEqual(im.n_frames, 2)
            self.assertEqual(im.get_format_mimetype(), "image/apng")
            self.assertTrue(im.info.get("default_image"))
            im.seek(1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

    def test_apng_save_split_fdat(self):
        # test to make sure we do not generate sequence errors when writing
        # frames with image data spanning multiple fdAT chunks (in this case
        # both the default image and first animation frame will span multiple
        # data chunks)
        test_file = self.tempfile("temp.png")
        with Image.open("Tests/images/old-style-jpeg-compression.png") as im:
            frames = [im.copy(), Image.new("RGBA", im.size, (255, 0, 0, 255))]
            im.save(
                test_file, save_all=True, default_image=True, append_images=frames,
            )
        with Image.open(test_file) as im:
            exception = None
            try:
                im.seek(im.n_frames - 1)
                im.load()
            except Exception as e:
                exception = e
            self.assertIsNone(exception)

    def test_apng_save_duration_loop(self):
        test_file = self.tempfile("temp.png")
        with Image.open("Tests/images/apng/delay.png") as im:
            frames = []
            durations = []
            loop = im.info.get("loop")
            default_image = im.info.get("default_image")
            for i, frame_im in enumerate(ImageSequence.Iterator(im)):
                frames.append(frame_im.copy())
                if i != 0 or not default_image:
                    durations.append(frame_im.info.get("duration", 0))
            frames[0].save(
                test_file,
                save_all=True,
                default_image=default_image,
                append_images=frames[1:],
                duration=durations,
                loop=loop,
            )

        with Image.open(test_file) as im:
            im.load()
            self.assertEqual(im.info.get("loop"), loop)
            im.seek(1)
            self.assertEqual(im.info.get("duration"), 500.0)
            im.seek(2)
            self.assertEqual(im.info.get("duration"), 1000.0)
            im.seek(3)
            self.assertEqual(im.info.get("duration"), 500.0)
            im.seek(4)
            self.assertEqual(im.info.get("duration"), 1000.0)

        # test removal of duplicated frames
        frame = Image.new("RGBA", (128, 64), (255, 0, 0, 255))
        frame.save(test_file, save_all=True, append_images=[frame], duration=[500, 250])
        with Image.open(test_file) as im:
            im.load()
            self.assertEqual(im.n_frames, 1)
            self.assertEqual(im.info.get("duration"), 750)

    def test_apng_save_disposal(self):
        test_file = self.tempfile("temp.png")
        size = (128, 64)
        red = Image.new("RGBA", size, (255, 0, 0, 255))
        green = Image.new("RGBA", size, (0, 255, 0, 255))
        transparent = Image.new("RGBA", size, (0, 0, 0, 0))

        # test APNG_DISPOSE_OP_NONE
        red.save(
            test_file,
            save_all=True,
            append_images=[green, transparent],
            disposal=PngImagePlugin.APNG_DISPOSE_OP_NONE,
            blend=PngImagePlugin.APNG_BLEND_OP_OVER,
        )
        with Image.open(test_file) as im:
            im.seek(2)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        # test APNG_DISPOSE_OP_BACKGROUND
        disposal = [
            PngImagePlugin.APNG_DISPOSE_OP_NONE,
            PngImagePlugin.APNG_DISPOSE_OP_BACKGROUND,
            PngImagePlugin.APNG_DISPOSE_OP_NONE,
        ]
        red.save(
            test_file,
            save_all=True,
            append_images=[red, transparent],
            disposal=disposal,
            blend=PngImagePlugin.APNG_BLEND_OP_OVER,
        )
        with Image.open(test_file) as im:
            im.seek(2)
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 0, 0))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 0, 0))

        disposal = [
            PngImagePlugin.APNG_DISPOSE_OP_NONE,
            PngImagePlugin.APNG_DISPOSE_OP_BACKGROUND,
        ]
        red.save(
            test_file,
            save_all=True,
            append_images=[green],
            disposal=disposal,
            blend=PngImagePlugin.APNG_BLEND_OP_OVER,
        )
        with Image.open(test_file) as im:
            im.seek(1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        # test APNG_DISPOSE_OP_PREVIOUS
        disposal = [
            PngImagePlugin.APNG_DISPOSE_OP_NONE,
            PngImagePlugin.APNG_DISPOSE_OP_PREVIOUS,
            PngImagePlugin.APNG_DISPOSE_OP_NONE,
        ]
        red.save(
            test_file,
            save_all=True,
            append_images=[green, red, transparent],
            default_image=True,
            disposal=disposal,
            blend=PngImagePlugin.APNG_BLEND_OP_OVER,
        )
        with Image.open(test_file) as im:
            im.seek(3)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        disposal = [
            PngImagePlugin.APNG_DISPOSE_OP_NONE,
            PngImagePlugin.APNG_DISPOSE_OP_PREVIOUS,
        ]
        red.save(
            test_file,
            save_all=True,
            append_images=[green],
            disposal=disposal,
            blend=PngImagePlugin.APNG_BLEND_OP_OVER,
        )
        with Image.open(test_file) as im:
            im.seek(1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

    def test_apng_save_blend(self):
        test_file = self.tempfile("temp.png")
        size = (128, 64)
        red = Image.new("RGBA", size, (255, 0, 0, 255))
        green = Image.new("RGBA", size, (0, 255, 0, 255))
        transparent = Image.new("RGBA", size, (0, 0, 0, 0))

        # test APNG_BLEND_OP_SOURCE on solid color
        blend = [
            PngImagePlugin.APNG_BLEND_OP_OVER,
            PngImagePlugin.APNG_BLEND_OP_SOURCE,
        ]
        red.save(
            test_file,
            save_all=True,
            append_images=[red, green],
            default_image=True,
            disposal=PngImagePlugin.APNG_DISPOSE_OP_NONE,
            blend=blend,
        )
        with Image.open(test_file) as im:
            im.seek(2)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))

        # test APNG_BLEND_OP_SOURCE on transparent color
        blend = [
            PngImagePlugin.APNG_BLEND_OP_OVER,
            PngImagePlugin.APNG_BLEND_OP_SOURCE,
        ]
        red.save(
            test_file,
            save_all=True,
            append_images=[red, transparent],
            default_image=True,
            disposal=PngImagePlugin.APNG_DISPOSE_OP_NONE,
            blend=blend,
        )
        with Image.open(test_file) as im:
            im.seek(2)
            self.assertEqual(im.getpixel((0, 0)), (0, 0, 0, 0))
            self.assertEqual(im.getpixel((64, 32)), (0, 0, 0, 0))

        # test APNG_BLEND_OP_OVER
        red.save(
            test_file,
            save_all=True,
            append_images=[green, transparent],
            default_image=True,
            disposal=PngImagePlugin.APNG_DISPOSE_OP_NONE,
            blend=PngImagePlugin.APNG_BLEND_OP_OVER,
        )
        with Image.open(test_file) as im:
            im.seek(1)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))
            im.seek(2)
            self.assertEqual(im.getpixel((0, 0)), (0, 255, 0, 255))
            self.assertEqual(im.getpixel((64, 32)), (0, 255, 0, 255))