matplotlib · timhoffm · Apr 1, 2021 · Mar 28, 2021
diff --git a/doc/api/next_api_changes/removals/19810-AL.rst b/doc/api/next_api_changes/removals/19810-AL.rst
@@ -0,0 +1,10 @@
+jpeg-related keywords and rcParams
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Support has been removed for the *quality*, *optimize*, and *progressive*
+parameters of `.Figure.savefig` (which only affected jpeg output), as well as
+:rc:`savefig.jpeg_quality`.  This support has also been removed from the
+corresponding ``print_jpg`` methods.
+
+JPEG output options can be set by directly passing the relevant parameters in
+*pil_kwargs*.
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -552,7 +552,6 @@ def gen_candidates():
     'animation.avconv_path': ('3.3',),
     'animation.avconv_args': ('3.3',),
     'animation.html_args': ('3.3',),
-    'savefig.jpeg_quality': ('3.3',),
 }
 
 

diff --git a/lib/matplotlib/backends/backend_agg.py b/lib/matplotlib/backends/backend_agg.py
@@ -522,14 +522,7 @@ def print_to_buffer(self):
     # print_figure(), and the latter ensures that `self.figure.dpi` already
     # matches the dpi kwarg (if any).
 
-    @_check_savefig_extra_args(
-        extra_kwargs=["quality", "optimize", "progressive"])
-    @_api.delete_parameter("3.3", "quality",
-                           alternative="pil_kwargs={'quality': ...}")
-    @_api.delete_parameter("3.3", "optimize",
-                           alternative="pil_kwargs={'optimize': ...}")
-    @_api.delete_parameter("3.3", "progressive",
-                           alternative="pil_kwargs={'progressive': ...}")
+    @_check_savefig_extra_args()
     @_api.delete_parameter("3.5", "args")
     def print_jpg(self, filename_or_obj, *args, pil_kwargs=None, **kwargs):
         """
@@ -542,23 +535,9 @@ def print_jpg(self, filename_or_obj, *args, pil_kwargs=None, **kwargs):
 
         Other Parameters
         ----------------
-        quality : int, default: :rc:`savefig.jpeg_quality`
-            The image quality, on a scale from 1 (worst) to 95 (best).
-            Values above 95 should be avoided; 100 disables portions of
-            the JPEG compression algorithm, and results in large files
-            with hardly any gain in image quality.  This parameter is
-            deprecated.
-        optimize : bool, default: False
-            Whether the encoder should make an extra pass over the image
-            in order to select optimal encoder settings.  This parameter is
-            deprecated.
-        progressive : bool, default: False
-            Whether the image should be stored as a progressive JPEG file.
-            This parameter is deprecated.
         pil_kwargs : dict, optional
             Additional keyword arguments that are passed to
-            `PIL.Image.Image.save` when saving the figure.  These take
-            precedence over *quality*, *optimize* and *progressive*.
+            `PIL.Image.Image.save` when saving the figure.
         """
         # Remove transparency by alpha-blending on an assumed white background.
         r, g, b, a = mcolors.to_rgba(self.figure.get_facecolor())
@@ -569,19 +548,6 @@ def print_jpg(self, filename_or_obj, *args, pil_kwargs=None, **kwargs):
             self.figure.set_facecolor((r, g, b, a))
         if pil_kwargs is None:
             pil_kwargs = {}
-        for k in ["quality", "optimize", "progressive"]:
-            if k in kwargs:
-                pil_kwargs.setdefault(k, kwargs.pop(k))
-        if "quality" not in pil_kwargs:
-            quality = pil_kwargs["quality"] = \
-                dict.__getitem__(mpl.rcParams, "savefig.jpeg_quality")
-            if quality not in [0, 75, 95]:  # default qualities.
-                _api.warn_deprecated(
-                    "3.3", name="savefig.jpeg_quality", obj_type="rcParam",
-                    addendum="Set the quality using "
-                    "`pil_kwargs={'quality': ...}`; the future default "
-                    "quality will be 75, matching the default of Pillow and "
-                    "libjpeg.")
         pil_kwargs.setdefault("dpi", (self.figure.dpi, self.figure.dpi))
         # Drop alpha channel now.
         return (Image.fromarray(np.asarray(self.buffer_rgba())[..., :3])

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -831,7 +831,7 @@ def draw(self, drawDC=None):
         self.gui_repaint(drawDC=drawDC)
 
     @_check_savefig_extra_args
-    def _print_image(self, filetype, filename, *, quality=None):
+    def _print_image(self, filetype, filename):
         origBitmap = self.bitmap
 
         self.bitmap = wx.Bitmap(math.ceil(self.figure.bbox.width),
@@ -843,16 +843,6 @@ def _print_image(self, filetype, filename, *, quality=None):
 
         # image is the object that we call SaveFile on.
         image = self.bitmap
-        # set the JPEG quality appropriately.  Unfortunately, it is only
-        # possible to set the quality on a wx.Image object.  So if we
-        # are saving a JPEG, convert the wx.Bitmap to a wx.Image,
-        # and set the quality.
-        if filetype == wx.BITMAP_TYPE_JPEG:
-            if quality is None:
-                quality = dict.__getitem__(mpl.rcParams,
-                                           'savefig.jpeg_quality')
-            image = self.bitmap.ConvertToImage()
-            image.SetOption(wx.IMAGE_OPTION_QUALITY, str(quality))
 
         # Now that we have rendered into the bitmap, save it to the appropriate
         # file type and clean up.

diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -2840,31 +2840,6 @@ def savefig(self, fname, *, transparent=None, **kwargs):
             The resolution in dots per inch.  If 'figure', use the figure's
             dpi value.
 
-        quality : int, default: :rc:`savefig.jpeg_quality`
-            Applicable only if *format* is 'jpg' or 'jpeg', ignored otherwise.
-
-            The image quality, on a scale from 1 (worst) to 95 (best).
-            Values above 95 should be avoided; 100 disables portions of
-            the JPEG compression algorithm, and results in large files
-            with hardly any gain in image quality.
-
-            This parameter is deprecated.
-
-        optimize : bool, default: False
-            Applicable only if *format* is 'jpg' or 'jpeg', ignored otherwise.
-
-            Whether the encoder should make an extra pass over the image
-            in order to select optimal encoder settings.
-
-            This parameter is deprecated.
-
-        progressive : bool, default: False
-            Applicable only if *format* is 'jpg' or 'jpeg', ignored otherwise.
-
-            Whether the image should be stored as a progressive JPEG file.
-
-            This parameter is deprecated.
-
         facecolor : color or 'auto', default: :rc:`savefig.facecolor`
             The facecolor of the figure.  If 'auto', use the current figure
             facecolor.

diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -1318,7 +1318,6 @@ def _convert_validator_spec(key, conv):
     'savefig.facecolor':    validate_color_or_auto,
     'savefig.edgecolor':    validate_color_or_auto,
     'savefig.orientation':  ['landscape', 'portrait'],
-    'savefig.jpeg_quality': validate_int,
     "savefig.format":       validate_string,
     "savefig.bbox":         validate_bbox,  # "tight", or "standard" (= None)
     "savefig.pad_inches":   validate_float,
@@ -1420,7 +1419,6 @@ def _convert_validator_spec(key, conv):
     "animation.avconv_path": "avconv",
     "animation.avconv_args": [],
     "animation.html_args": [],
-    "savefig.jpeg_quality": 95,
 }
 _validators = {k: _convert_validator_spec(k, conv)
                for k, conv in _validators.items()}
diff --git a/lib/matplotlib/tests/test_image.py b/lib/matplotlib/tests/test_image.py
@@ -636,7 +636,7 @@ def test_jpeg_alpha():
     # If this fails, there will be only one color (all black). If this
     # is working, we should have all 256 shades of grey represented.
     num_colors = len(image.getcolors(256))
-    assert 175 <= num_colors <= 185
+    assert 175 <= num_colors <= 210
     # The fully transparent part should be red.
     corner_pixel = image.getpixel((0, 0))
     assert corner_pixel == (254, 0, 0)