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Populate JPEG DPI from JFIF cm density #8633

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Merged
hugovk merged 1 commit into from
Dec 29, 2024
Merged

Populate JPEG DPI from JFIF cm density #8633

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Binary file added Tests/images/jfif_unit_cm.jpg
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4 changes: 4 additions & 0 deletions Tests/test_file_jpeg.py
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Original file line number Diff line number Diff line change
Expand Up @@ -181,6 +181,10 @@ def test(xdpi: int, ydpi: int | None = None) -> tuple[int, int] | None:
assert test(100, 200) == (100, 200)
assert test(0) is None # square pixels

def test_dpi_jfif_cm(self):
with Image.open("Tests/images/jfif_unit_cm.jpg") as im:
assert im.info["dpi"] == (2.54, 5.08)

@mark_if_feature_version(
pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
)
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3 changes: 3 additions & 0 deletions src/PIL/JpegImagePlugin.py
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Expand Up @@ -90,6 +90,9 @@ def APP(self: JpegImageFile, marker: int) -> None:
else:
if jfif_unit == 1:
self.info["dpi"] = jfif_density
elif jfif_unit == 2: # cm
# 1 dpcm = 2.54 dpi
self.info["dpi"] = tuple(d * 2.54 for d in jfif_density)
self.info["jfif_unit"] = jfif_unit
self.info["jfif_density"] = jfif_density
elif marker == 0xFFE1 and s[:6] == b"Exif\0\0":
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