Removed DPI rounding when BMP loading

python-pillow · May 7, 2021 · 0de3bea · 0de3bea
1 parent 9d72542
commit 0de3bea
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Showing 3 changed files with 8 additions and 23 deletions.
diff --git a/Tests/images/hopper_roundDown.bmp b/Tests/images/hopper_roundDown.bmp
diff --git a/Tests/test_file_bmp.py b/Tests/test_file_bmp.py
@@ -63,46 +63,33 @@ def test_dpi():
 
     output.seek(0)
     with Image.open(output) as reloaded:
-        assert reloaded.info["dpi"] == dpi
+        assert reloaded.info["dpi"] == (72.008961115161, 72.008961115161)
 
 
 def test_save_bmp_with_dpi(tmp_path):
     # Test for #1301
     # Arrange
     outfile = str(tmp_path / "temp.jpg")
     with Image.open("Tests/images/hopper.bmp") as im:
+        assert im.info["dpi"] == (95.98654816726399, 95.98654816726399)
 
         # Act
         im.save(outfile, "JPEG", dpi=im.info["dpi"])
 
         # Assert
         with Image.open(outfile) as reloaded:
             reloaded.load()
-            assert im.info["dpi"] == reloaded.info["dpi"]
-            assert im.size == reloaded.size
+            assert reloaded.info["dpi"] == (96, 96)
+            assert reloaded.size == im.size
             assert reloaded.format == "JPEG"
 
 
-def test_load_dpi_rounding():
-    # Round up
-    with Image.open("Tests/images/hopper.bmp") as im:
-        assert im.info["dpi"] == (96, 96)
-
-    # Round down
-    with Image.open("Tests/images/hopper_roundDown.bmp") as im:
-        assert im.info["dpi"] == (72, 72)
-
-
-def test_save_dpi_rounding(tmp_path):
+def test_save_float_dpi(tmp_path):
     outfile = str(tmp_path / "temp.bmp")
     with Image.open("Tests/images/hopper.bmp") as im:
-        im.save(outfile, dpi=(72.2, 72.2))
+        im.save(outfile, dpi=(72.21216100543306, 72.21216100543306))
         with Image.open(outfile) as reloaded:
-            assert reloaded.info["dpi"] == (72, 72)
-
-        im.save(outfile, dpi=(72.8, 72.8))
-    with Image.open(outfile) as reloaded:
-        assert reloaded.info["dpi"] == (73, 73)
+            assert reloaded.info["dpi"] == (72.21216100543306, 72.21216100543306)
 
 
 def test_load_dib():

diff --git a/src/PIL/BmpImagePlugin.py b/src/PIL/BmpImagePlugin.py
@@ -115,9 +115,7 @@ def _bitmap(self, header=0, offset=0):
             )
             file_info["colors"] = i32(header_data, 28)
             file_info["palette_padding"] = 4
-            self.info["dpi"] = tuple(
-                int(x / 39.3701 + 0.5) for x in file_info["pixels_per_meter"]
-            )
+            self.info["dpi"] = tuple(x / 39.3701 for x in file_info["pixels_per_meter"])
             if file_info["compression"] == self.BITFIELDS:
                 if len(header_data) >= 52:
                     for idx, mask in enumerate(