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Support reading grayscale JPEG2000 images with 4 channels #8786

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Merged
hugovk merged 1 commit into from
Mar 5, 2025
+13 −0
Merged

Support reading grayscale JPEG2000 images with 4 channels #8786

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12 changes: 12 additions & 0 deletions Tests/test_file_jpeg2k.py
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Original file line number Diff line number Diff line change
Expand Up @@ -313,6 +313,18 @@ def test_rgba(ext: str) -> None:
assert im.mode == "RGBA"


def test_grayscale_four_channels() -> None:
with open("Tests/images/rgb_trns_ycbc.jp2", "rb") as fp:
data = fp.read()

# Change color space to OPJ_CLRSPC_GRAY
data = data[:76] + b"\x11" + data[77:]

with Image.open(BytesIO(data)) as im:
im.load()
assert im.mode == "RGBA"


@pytest.mark.skipif(
not os.path.exists(EXTRA_DIR), reason="Extra image files not installed"
)
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1 change: 1 addition & 0 deletions src/libImaging/Jpeg2KDecode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -615,6 +615,7 @@ static const struct j2k_decode_unpacker j2k_unpackers[] = {
{"RGBA", OPJ_CLRSPC_GRAY, 2, 0, j2ku_graya_la},
{"RGBA", OPJ_CLRSPC_SRGB, 3, 1, j2ku_srgb_rgb},
{"RGBA", OPJ_CLRSPC_SYCC, 3, 1, j2ku_sycc_rgb},
{"RGBA", OPJ_CLRSPC_GRAY, 4, 1, j2ku_srgba_rgba},
{"RGBA", OPJ_CLRSPC_SRGB, 4, 1, j2ku_srgba_rgba},
{"RGBA", OPJ_CLRSPC_SYCC, 4, 1, j2ku_sycca_rgba},
{"CMYK", OPJ_CLRSPC_CMYK, 4, 1, j2ku_srgba_rgba},
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