From 5554e778bba52f2414d0151642a2906aed254ad2 Mon Sep 17 00:00:00 2001 From: Andrew Murray Date: Sat, 5 Jul 2025 13:18:48 +1000 Subject: [PATCH 1/2] Removed unnecessary checks --- src/libImaging/AlphaComposite.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/src/libImaging/AlphaComposite.c b/src/libImaging/AlphaComposite.c index 6d728f908..e14af0dea 100644 --- a/src/libImaging/AlphaComposite.c +++ b/src/libImaging/AlphaComposite.c @@ -25,13 +25,11 @@ ImagingAlphaComposite(Imaging imDst, Imaging imSrc) { int x, y; /* Check arguments */ - if (!imDst || !imSrc || strcmp(imDst->mode, "RGBA") || - imDst->type != IMAGING_TYPE_UINT8 || imDst->bands != 4) { + if (!imDst || !imSrc || strcmp(imDst->mode, "RGBA")) { return ImagingError_ModeError(); } - if (strcmp(imDst->mode, imSrc->mode) || imDst->type != imSrc->type || - imDst->bands != imSrc->bands || imDst->xsize != imSrc->xsize || + if (strcmp(imDst->mode, imSrc->mode) || imDst->xsize != imSrc->xsize || imDst->ysize != imSrc->ysize) { return ImagingError_Mismatch(); } From 3152da47355ed3f9b342dc94de8a2214798842c4 Mon Sep 17 00:00:00 2001 From: Andrew Murray Date: Sat, 5 Jul 2025 13:51:18 +1000 Subject: [PATCH 2/2] Allow alpha_composite to use LA images --- Tests/test_image.py | 31 +++++++++++++++++++++++++++++++ src/PIL/Image.py | 5 ++--- src/libImaging/AlphaComposite.c | 3 ++- 3 files changed, 35 insertions(+), 4 deletions(-) diff --git a/Tests/test_image.py b/Tests/test_image.py index 6b8b6d42b..e4c25693a 100644 --- a/Tests/test_image.py +++ b/Tests/test_image.py @@ -398,6 +398,37 @@ class TestImage: assert img_colors is not None assert sorted(img_colors) == expected_colors + def test_alpha_composite_la(self) -> None: + # Arrange + expected_colors = sorted( + [ + (3300, (255, 255)), + (1156, (170, 192)), + (1122, (128, 255)), + (1089, (0, 0)), + (1122, (255, 128)), + (1122, (0, 128)), + (1089, (0, 255)), + ] + ) + + dst = Image.new("LA", size=(100, 100), color=(0, 255)) + draw = ImageDraw.Draw(dst) + draw.rectangle((0, 33, 100, 66), fill=(0, 128)) + draw.rectangle((0, 67, 100, 100), fill=(0, 0)) + src = Image.new("LA", size=(100, 100), color=(255, 255)) + draw = ImageDraw.Draw(src) + draw.rectangle((33, 0, 66, 100), fill=(255, 128)) + draw.rectangle((67, 0, 100, 100), fill=(255, 0)) + + # Act + img = Image.alpha_composite(dst, src) + + # Assert + img_colors = img.getcolors() + assert img_colors is not None + assert sorted(img_colors) == expected_colors + def test_alpha_inplace(self) -> None: src = Image.new("RGBA", (128, 128), "blue") diff --git a/src/PIL/Image.py b/src/PIL/Image.py index d209405c4..f4f1eea79 100644 --- a/src/PIL/Image.py +++ b/src/PIL/Image.py @@ -3588,9 +3588,8 @@ def alpha_composite(im1: Image, im2: Image) -> Image: """ Alpha composite im2 over im1. - :param im1: The first image. Must have mode RGBA. - :param im2: The second image. Must have mode RGBA, and the same size as - the first image. + :param im1: The first image. Must have mode RGBA or LA. + :param im2: The second image. Must have the same mode and size as the first image. :returns: An :py:class:`~PIL.Image.Image` object. """ diff --git a/src/libImaging/AlphaComposite.c b/src/libImaging/AlphaComposite.c index e14af0dea..44c451679 100644 --- a/src/libImaging/AlphaComposite.c +++ b/src/libImaging/AlphaComposite.c @@ -25,7 +25,8 @@ ImagingAlphaComposite(Imaging imDst, Imaging imSrc) { int x, y; /* Check arguments */ - if (!imDst || !imSrc || strcmp(imDst->mode, "RGBA")) { + if (!imDst || !imSrc || + (strcmp(imDst->mode, "RGBA") && strcmp(imDst->mode, "LA"))) { return ImagingError_ModeError(); }