diff --git a/Tests/test_file_gif.py b/Tests/test_file_gif.py index 926f5c1eea8..a196c1612e8 100644 --- a/Tests/test_file_gif.py +++ b/Tests/test_file_gif.py @@ -859,14 +859,23 @@ def test_background(tmp_path): im.info["background"] = 1 im.save(out) with Image.open(out) as reread: - assert reread.info["background"] == im.info["background"] + +def test_webp_background(tmp_path): + out = str(tmp_path / "temp.gif") + + # Test opaque WebP background if features.check("webp") and features.check("webp_anim"): with Image.open("Tests/images/hopper.webp") as im: - assert isinstance(im.info["background"], tuple) + assert im.info["background"] == (255, 255, 255, 255) im.save(out) + # Test non-opaque WebP background + im = Image.new("L", (100, 100), "#000") + im.info["background"] = (0, 0, 0, 0) + im.save(out) + def test_comment(tmp_path): with Image.open(TEST_GIF) as im: diff --git a/src/PIL/GifImagePlugin.py b/src/PIL/GifImagePlugin.py index dd1b21f2e63..01518b378e6 100644 --- a/src/PIL/GifImagePlugin.py +++ b/src/PIL/GifImagePlugin.py @@ -886,20 +886,23 @@ def _get_palette_bytes(im): def _get_background(im, info_background): background = 0 if info_background: - background = info_background - if isinstance(background, tuple): + if isinstance(info_background, tuple): # WebPImagePlugin stores an RGBA value in info["background"] # So it must be converted to the same format as GifImagePlugin's # info["background"] - a global color table index try: - background = im.palette.getcolor(background, im) + background = im.palette.getcolor(info_background, im) except ValueError as e: - if str(e) == "cannot allocate more than 256 colors": + if str(e) not in ( # If all 256 colors are in use, # then there is no need for the background color - return 0 - else: + "cannot allocate more than 256 colors", + # Ignore non-opaque WebP background + "cannot add non-opaque RGBA color to RGB palette", + ): raise + else: + background = info_background return background