Deprecate JpegImageFile.load_djpeg (#9924)

Co-authored-by: Andrew Murray <radarhere@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Andrew Murray <3112309+radarhere@users.noreply.github.com>

Author: 3 people

Tests/test_file_jpeg.py

@@ -734,7 +734,8 @@ def test_restart_markers(self, blocks: int, rows: int, markers: int) -> None:
     def test_load_djpeg(self) -> None:
         with Image.open(TEST_FILE) as img:
             assert isinstance(img, JpegImagePlugin.JpegImageFile)
-            img.load_djpeg()
+            with pytest.warns(DeprecationWarning, match="load_djpeg"):
+                img.load_djpeg()
             assert_image_similar_tofile(img, TEST_FILE, 5)
 
     def test_no_duplicate_0x1001_tag(self) -> None:

Tests/test_shell_injection.py

@@ -44,7 +44,8 @@ def test_load_djpeg_filename(self, tmp_path: Path) -> None:
 
             with Image.open(src_file) as im:
                 assert isinstance(im, JpegImagePlugin.JpegImageFile)
-                im.load_djpeg()
+                with pytest.warns(DeprecationWarning, match="load_djpeg"):
+                    im.load_djpeg()
 
     @pytest.mark.skipif(not netpbm_available(), reason="Netpbm not available")
     def test_save_netpbm_filename_bmp_mode(self, tmp_path: Path) -> None:

docs/deprecations.rst

@@ -30,6 +30,18 @@ Image getdata()
 identical, except that it returns a tuple of pixel values, instead of an internal
 Pillow data type.
 
+
+JpegImageFile.load_djpeg
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. deprecated:: 13.0.0
+
+``JpegImageFile.load_djpeg`` has been deprecated, and will be removed in Pillow 14
+(2027-10-15).
+
+Use the built-in JPEG decoder instead, or call ``djpeg`` directly and decode the
+resulting image with Pillow.
+
 Removed features
 ----------------
 

docs/releasenotes/13.0.0.rst

@@ -69,10 +69,14 @@ ImageCms.ImageCmsProfile.product_name and .product_info
 Deprecations
 ============
 
-TODO
-^^^^
+JpegImageFile.load_djpeg
+^^^^^^^^^^^^^^^^^^^^^^^^
 
-TODO
+``JpegImageFile.load_djpeg`` has been deprecated, and will be removed in Pillow 14
+(2027-10-15).
+
+Use the built-in JPEG decoder instead, or call ``djpeg`` directly and decode the
+resulting image with Pillow.
 
 API changes
 ===========

src/PIL/JpegImagePlugin.py

@@ -48,6 +48,7 @@
 from ._binary import i32be as i32
 from ._binary import o8
 from ._binary import o16be as o16
+from ._deprecate import deprecate
 from .JpegPresets import presets
 
 TYPE_CHECKING = False
@@ -467,6 +468,11 @@ def draft(
 
     def load_djpeg(self) -> None:
         # ALTERNATIVE: handle JPEGs via the IJG command line utilities
+        deprecate(
+            "load_djpeg",
+            14,
+            action="Use the built-in JPEG decoder instead, or call djpeg yourself.",
+        )
 
         f, path = tempfile.mkstemp()
         os.close(f)