python-pillow/Pillow
1
1
Fork 0
mirror of https://github.com/python-pillow/Pillow.git synced 2025-01-13 10:46:16 +03:00
Code Issues Packages Projects Releases Wiki Activity

If all 256 colors are in use, then there is no need for an additional color for background or transparency

Browse Source
This commit is contained in:
Andrew Murray 2021-06-23 19:28:46 +10:00
parent fa559277fb
commit 8210645e4b
3 changed files with 39 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Tests/test_imagepalette.py
View File

@ -31,8 +31,11 @@ def test_getcolor():
assert palette.getcolor((0, 0, 0)) == palette.getcolor((0, 0, 0, 255))
# An error is raised when the palette is full
with pytest.raises(ValueError):
palette.getcolor((1, 2, 3))
# But not if the image is not using one of the palette entries
palette.getcolor((1, 2, 3), image=Image.new("P", (1, 1)))
# Test unknown color specifier
with pytest.raises(ValueError):

10
src/PIL/GifImagePlugin.py
View File

@ -760,7 +760,15 @@ def _get_background(im, infoBackground):
# 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
background = im.palette.getcolor(background, im)
try:
background = im.palette.getcolor(background, im)
except ValueError as e:
if str(e) == "cannot allocate more than 256 colors":
# If all 256 colors are in use,
# then there is no need for the background color
return 0
else:
raise
return background

41
src/PIL/Image.py
View File

@ -979,19 +979,27 @@ class Image:
if isinstance(t, tuple):
try:
t = trns_im.palette.getcolor(t, self)
except Exception as e:
raise ValueError(
"Couldn't allocate a palette color for transparency"
) from e
trns_im.putpixel((0, 0), t)
if mode in ("L", "RGB"):
trns_im = trns_im.convert(mode)
except ValueError as e:
if str(e) == "cannot allocate more than 256 colors":
# If all 256 colors are in use,
# then there is no need for transparency
t = None
else:
raise ValueError(
"Couldn't allocate a palette color for transparency"
) from e
if t is None:
trns = None
else:
# can't just retrieve the palette number, got to do it
# after quantization.
trns_im = trns_im.convert("RGB")
trns = trns_im.getpixel((0, 0))
trns_im.putpixel((0, 0), t)
if mode in ("L", "RGB"):
trns_im = trns_im.convert(mode)
else:
# can't just retrieve the palette number, got to do it
# after quantization.
trns_im = trns_im.convert("RGB")
trns = trns_im.getpixel((0, 0))
elif self.mode == "P" and mode == "RGBA":
t = self.info["transparency"]
@ -1050,9 +1058,14 @@ class Image:
if new_im.mode == "P":
try:
new_im.info["transparency"] = new_im.palette.getcolor(trns, new_im)
except Exception:
except ValueError as e:
del new_im.info["transparency"]
warnings.warn("Couldn't allocate palette entry for transparency")
if str(e) != "cannot allocate more than 256 colors":
# If all 256 colors are in use,
# then there is no need for transparency
warnings.warn(
"Couldn't allocate palette entry for transparency"
)
else:
new_im.info["transparency"] = trns
return new_im