Merge pull request matplotlib#15571 from timhoffm/pillow-cleanup

Cleanup following using Pillow as universal image reader

Author: tacaswell

INSTALL.rst

@@ -46,7 +46,7 @@ To run the test suite:
 * extract the :file:`lib/matplotlib/tests` or :file:`lib/mpl_toolkits/tests`
   directories from the source distribution;
 * install test dependencies: `pytest <https://pypi.org/project/pytest>`_,
-  Pillow, MiKTeX, GhostScript, ffmpeg, avconv, ImageMagick, and `Inkscape
+  MiKTeX, GhostScript, ffmpeg, avconv, ImageMagick, and `Inkscape
   <https://inkscape.org/>`_;
 * run ``python -mpytest``.
 
@@ -115,6 +115,7 @@ Matplotlib requires the following dependencies:
 * `cycler <http://matplotlib.org/cycler/>`_ (>= 0.10.0)
 * `dateutil <https://pypi.org/project/python-dateutil>`_ (>= 2.1)
 * `kiwisolver <https://github.com/nucleic/kiwi>`_ (>= 1.0.0)
+* `Pillow <https://pillow.readthedocs.io/en/latest/>`_ (>= 6.2)
 * `pyparsing <https://pyparsing.wikispaces.com/>`_
 
 Optionally, you can also install a number of packages to enable better user
@@ -149,8 +150,6 @@ etc., you can install the following:
   <https://libav.org/avconv.html>`_: for saving movies;
 * `ImageMagick <https://www.imagemagick.org/script/index.php>`_: for saving
   animated gifs;
-* `Pillow <https://pillow.readthedocs.io/en/latest/>`_ (>= 3.4): for a larger
-  selection of image file formats: JPEG, BMP, and TIFF image files;
 * `LaTeX <https://miktex.org/>`_ and `GhostScript (>=9.0)
   <https://ghostscript.com/download/>`_ : for rendering text with LaTeX.
 

lib/matplotlib/figure.py

@@ -2143,9 +2143,7 @@ def savefig(self, fname, *, transparent=None, **kwargs):
 
         pil_kwargs : dict, optional
             Additional keyword arguments that are passed to `PIL.Image.save`
-            when saving the figure.  Only applicable for formats that are saved
-            using Pillow, i.e. JPEG, TIFF, and (if the keyword is set to a
-            non-None value) PNG.
+            when saving the figure.
         """
 
         kwargs.setdefault('dpi', rcParams['savefig.dpi'])

lib/matplotlib/image.py

@@ -1628,8 +1628,9 @@ def thumbnail(infile, thumbfile, scale=0.1, interpolation='bilinear',
     Parameters
     ----------
     infile : str or file-like
-        The image file -- must be PNG, or Pillow-readable if you have Pillow_
-        installed.
+        The image file. Matplotlib relies on Pillow_ for image reading, and
+        thus supports a wide range of file formats, including PNG, JPG, TIFF
+        and others.
 
         .. _Pillow: http://python-pillow.org/
 

lib/matplotlib/tests/test_agg.py

@@ -2,8 +2,10 @@
 
 import numpy as np
 from numpy.testing import assert_array_almost_equal
+from PIL import Image, TiffTags
 import pytest
 
+
 from matplotlib import (
     collections, path, pyplot as plt, transforms as mtransforms, rcParams)
 from matplotlib.image import imread
@@ -217,7 +219,6 @@ def test_chunksize():
 
 @pytest.mark.backend('Agg')
 def test_jpeg_dpi():
-    Image = pytest.importorskip("PIL.Image")
     # Check that dpi is set correctly in jpg files.
     plt.plot([0, 1, 2], [0, 1, 0])
     buf = io.BytesIO()
@@ -227,7 +228,6 @@ def test_jpeg_dpi():
 
 
 def test_pil_kwargs_png():
-    Image = pytest.importorskip("PIL.Image")
     from PIL.PngImagePlugin import PngInfo
     buf = io.BytesIO()
     pnginfo = PngInfo()
@@ -238,11 +238,9 @@ def test_pil_kwargs_png():
 
 
 def test_pil_kwargs_tiff():
-    Image = pytest.importorskip("PIL.Image")
-    from PIL.TiffTags import TAGS_V2 as TAGS
     buf = io.BytesIO()
     pil_kwargs = {"description": "test image"}
     plt.figure().savefig(buf, format="tiff", pil_kwargs=pil_kwargs)
     im = Image.open(buf)
-    tags = {TAGS[k].name: v for k, v in im.tag_v2.items()}
+    tags = {TiffTags.TAGS_V2[k].name: v for k, v in im.tag_v2.items()}
     assert tags["ImageDescription"] == "test image"

lib/matplotlib/tests/test_animation.py

@@ -132,8 +132,6 @@ def isAvailable(cls):
 # matplotlib.testing.image_comparison
 @pytest.mark.parametrize('writer, output', WRITER_OUTPUT)
 def test_save_animation_smoketest(tmpdir, writer, output):
-    if writer == 'pillow':
-        pytest.importorskip("PIL")
     try:
         # for ImageMagick the rcparams must be patched to account for
         # 'convert' being a built in MS tool, not the imagemagick

lib/matplotlib/tests/test_image.py

@@ -11,6 +11,7 @@
 import numpy as np
 from numpy import ma
 from numpy.testing import assert_array_equal
+from PIL import Image
 
 from matplotlib import (
     colors, image as mimage, patches, pyplot as plt, style, rcParams)
@@ -219,31 +220,24 @@ def test_imshow_zoom(fig_test, fig_ref):
 @check_figures_equal()
 def test_imshow_pil(fig_test, fig_ref):
     style.use("default")
-    PIL = pytest.importorskip("PIL")
-    # Pillow<=6.0 fails to open pathlib.Paths on Windows (pillow#3823), and
-    # Matplotlib's builtin png opener doesn't handle them either.
-    png_path = str(
-        Path(__file__).parent / "baseline_images/pngsuite/basn3p04.png")
-    tiff_path = str(
-        Path(__file__).parent / "baseline_images/test_image/uint16.tif")
+    png_path = Path(__file__).parent / "baseline_images/pngsuite/basn3p04.png"
+    tiff_path = Path(__file__).parent / "baseline_images/test_image/uint16.tif"
     axs = fig_test.subplots(2)
-    axs[0].imshow(PIL.Image.open(png_path))
-    axs[1].imshow(PIL.Image.open(tiff_path))
+    axs[0].imshow(Image.open(png_path))
+    axs[1].imshow(Image.open(tiff_path))
     axs = fig_ref.subplots(2)
     axs[0].imshow(plt.imread(png_path))
     axs[1].imshow(plt.imread(tiff_path))
 
 
 def test_imread_pil_uint16():
-    pytest.importorskip("PIL")
     img = plt.imread(os.path.join(os.path.dirname(__file__),
                      'baseline_images', 'test_image', 'uint16.tif'))
     assert img.dtype == np.uint16
     assert np.sum(img) == 134184960
 
 
 def test_imread_fspath():
-    pytest.importorskip("PIL")
     img = plt.imread(
         Path(__file__).parent / 'baseline_images/test_image/uint16.tif')
     assert img.dtype == np.uint16
@@ -252,8 +246,6 @@ def test_imread_fspath():
 
 @pytest.mark.parametrize("fmt", ["png", "jpg", "jpeg", "tiff"])
 def test_imsave(fmt):
-    if fmt in ["jpg", "jpeg", "tiff"]:
-        pytest.importorskip("PIL")
     has_alpha = fmt not in ["jpg", "jpeg"]
 
     # The goal here is that the user can specify an output logical DPI
@@ -318,7 +310,6 @@ def test_imsave_color_alpha():
 
 
 def test_imsave_pil_kwargs_png():
-    Image = pytest.importorskip("PIL.Image")
     from PIL.PngImagePlugin import PngInfo
     buf = io.BytesIO()
     pnginfo = PngInfo()
@@ -330,7 +321,6 @@ def test_imsave_pil_kwargs_png():
 
 
 def test_imsave_pil_kwargs_tiff():
-    Image = pytest.importorskip("PIL.Image")
     from PIL.TiffTags import TAGS_V2 as TAGS
     buf = io.BytesIO()
     pil_kwargs = {"description": "test image"}
@@ -668,7 +658,6 @@ def test_nonuniformimage_setnorm():
 
 
 def test_jpeg_2d():
-    Image = pytest.importorskip('PIL.Image')
     # smoke test that mode-L pillow images work.
     imd = np.ones((10, 10), dtype='uint8')
     for i in range(10):
@@ -680,8 +669,6 @@ def test_jpeg_2d():
 
 
 def test_jpeg_alpha():
-    Image = pytest.importorskip('PIL.Image')
-
     plt.figure(figsize=(1, 1), dpi=300)
     # Create an image that is all black, with a gradient from 0-1 in
     # the alpha channel from left to right.