Merge pull request #6176 from radarhere/gif_transparency

Improve transparency handling when saving GIF
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Hugo van Kemenade 2022-05-27 08:31:37 +02:00 committed by GitHub
commit 27f5c4d8fb
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4 changed files with 52 additions and 2 deletions

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@ -639,7 +639,8 @@ def test_dispose2_background(tmp_path):
assert im.getpixel((0, 0)) == (255, 0, 0)
def test_transparency_in_second_frame():
def test_transparency_in_second_frame(tmp_path):
out = str(tmp_path / "temp.gif")
with Image.open("Tests/images/different_transparency.gif") as im:
assert im.info["transparency"] == 0
@ -649,6 +650,14 @@ def test_transparency_in_second_frame():
assert_image_equal_tofile(im, "Tests/images/different_transparency_merged.png")
im.save(out, save_all=True)
with Image.open(out) as reread:
reread.seek(reread.tell() + 1)
assert_image_equal_tofile(
reread, "Tests/images/different_transparency_merged.png"
)
def test_no_transparency_in_second_frame():
with Image.open("Tests/images/iss634.gif") as img:
@ -660,6 +669,22 @@ def test_no_transparency_in_second_frame():
assert img.histogram()[255] == 0
def test_remapped_transparency(tmp_path):
out = str(tmp_path / "temp.gif")
im = Image.new("P", (1, 2))
im2 = im.copy()
# Add transparency at a higher index
# so that it will be optimized to a lower index
im.putpixel((0, 1), 5)
im.info["transparency"] = 5
im.save(out, save_all=True, append_images=[im2])
with Image.open(out) as reloaded:
assert reloaded.info["transparency"] == reloaded.getpixel((0, 1))
def test_duration(tmp_path):
duration = 1000

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@ -609,6 +609,20 @@ class TestImage:
with pytest.raises(ValueError):
im.remap_palette(None)
def test_remap_palette_transparency(self):
im = Image.new("P", (1, 2))
im.putpixel((0, 1), 1)
im.info["transparency"] = 0
im_remapped = im.remap_palette([1, 0])
assert im_remapped.info["transparency"] == 1
# Test unused transparency
im.info["transparency"] = 2
im_remapped = im.remap_palette([1, 0])
assert "transparency" not in im_remapped.info
def test__new(self):
im = hopper("RGB")
im_p = hopper("P")

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@ -574,10 +574,14 @@ def _write_multiple_frames(im, fp, palette):
im_frame = _normalize_mode(im_frame.copy())
if frame_count == 0:
for k, v in im_frame.info.items():
if k == "transparency":
continue
im.encoderinfo.setdefault(k, v)
im_frame = _normalize_palette(im_frame, palette, im.encoderinfo)
encoderinfo = im.encoderinfo.copy()
im_frame = _normalize_palette(im_frame, palette, encoderinfo)
if "transparency" in im_frame.info:
encoderinfo.setdefault("transparency", im_frame.info["transparency"])
if isinstance(duration, (list, tuple)):
encoderinfo["duration"] = duration[frame_count]
elif duration is None and "duration" in im_frame.info:

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@ -1909,6 +1909,13 @@ class Image:
m_im.putpalette(new_palette_bytes)
m_im.palette = ImagePalette.ImagePalette("RGB", palette=palette_bytes)
if "transparency" in self.info:
try:
m_im.info["transparency"] = dest_map.index(self.info["transparency"])
except ValueError:
if "transparency" in m_im.info:
del m_im.info["transparency"]
return m_im
def _get_safe_box(self, size, resample, box):