Merge branch 'main' into webp-get-next-without-gil

.coveragerc

@@ -10,6 +10,11 @@ exclude_also =
     if DEBUG:
     # Don't complain about compatibility code for missing optional dependencies
     except ImportError
+    if TYPE_CHECKING:
+    @abc.abstractmethod
+    # Empty bodies in protocols or abstract methods
+    ^\s*def [a-zA-Z0-9_]+\(.*\)(\s*->.*)?:\s*\.\.\.(\s*#.*)?$
+    ^\s*\.\.\.(\s*#.*)?$
 
 [run]
 omit =

Tests/helper.py

@@ -244,7 +244,7 @@ def fromstring(data: bytes) -> Image.Image:
     return Image.open(BytesIO(data))
 
 
-def tostring(im: Image.Image, string_format: str, **options: dict[str, Any]) -> bytes:
+def tostring(im: Image.Image, string_format: str, **options: Any) -> bytes:
     out = BytesIO()
     im.save(out, string_format, **options)
     return out.getvalue()

Tests/test_bmp_reference.py

@@ -10,7 +10,7 @@ from .helper import assert_image_similar
 base = os.path.join("Tests", "images", "bmp")
 
 
-def get_files(d, ext: str = ".bmp"):
+def get_files(d: str, ext: str = ".bmp") -> list[str]:
     return [
         os.path.join(base, d, f) for f in os.listdir(os.path.join(base, d)) if ext in f
     ]
@@ -29,7 +29,7 @@ def test_bad() -> None:
                 pass
 
 
-def test_questionable():
+def test_questionable() -> None:
     """These shouldn't crash/dos, but it's not well defined that these
     are in spec"""
     supported = [
@@ -80,7 +80,7 @@ def test_good() -> None:
         "rgb32bf.bmp": "rgb24.png",
     }
 
-    def get_compare(f):
+    def get_compare(f: str) -> str:
         name = os.path.split(f)[1]
         if name in file_map:
             return os.path.join(base, "html", file_map[name])

Tests/test_box_blur.py

@@ -23,11 +23,11 @@ def test_imageops_box_blur() -> None:
     assert isinstance(i, Image.Image)
 
 
-def box_blur(image, radius: int = 1, n: int = 1):
+def box_blur(image: Image.Image, radius: float = 1, n: int = 1) -> Image.Image:
     return image._new(image.im.box_blur((radius, radius), n))
 
 
-def assert_image(im, data, delta: int = 0) -> None:
+def assert_image(im: Image.Image, data: list[list[int]], delta: int = 0) -> None:
     it = iter(im.getdata())
     for data_row in data:
         im_row = [next(it) for _ in range(im.size[0])]
@@ -37,7 +37,13 @@ def assert_image(im, data, delta: int = 0) -> None:
         next(it)
 
 
-def assert_blur(im, radius, data, passes: int = 1, delta: int = 0) -> None:
+def assert_blur(
+    im: Image.Image,
+    radius: float,
+    data: list[list[int]],
+    passes: int = 1,
+    delta: int = 0,
+) -> None:
     # check grayscale image
     assert_image(box_blur(im, radius, passes), data, delta)
     rgba = Image.merge("RGBA", (im, im, im, im))

Tests/test_color_lut.py

@@ -15,7 +15,9 @@ except ImportError:
 
 
 class TestColorLut3DCoreAPI:
-    def generate_identity_table(self, channels, size):
+    def generate_identity_table(
+        self, channels: int, size: int | tuple[int, int, int]
+    ) -> tuple[int, int, int, int, list[float]]:
         if isinstance(size, tuple):
             size_1d, size_2d, size_3d = size
         else:

Tests/test_file_apng.py

@@ -47,7 +47,7 @@ def test_apng_basic() -> None:
     "filename",
     ("Tests/images/apng/split_fdat.png", "Tests/images/apng/split_fdat_zero_chunk.png"),
 )
-def test_apng_fdat(filename) -> None:
+def test_apng_fdat(filename: str) -> None:
     with Image.open(filename) as im:
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
@@ -338,7 +338,7 @@ def test_apng_syntax_errors() -> None:
         "sequence_fdat_fctl.png",
     ),
 )
-def test_apng_sequence_errors(test_file) -> None:
+def test_apng_sequence_errors(test_file: str) -> None:
     with pytest.raises(SyntaxError):
         with Image.open(f"Tests/images/apng/{test_file}") as im:
             im.seek(im.n_frames - 1)
@@ -681,7 +681,7 @@ def test_seek_after_close() -> None:
 @pytest.mark.parametrize("default_image", (True, False))
 @pytest.mark.parametrize("duplicate", (True, False))
 def test_different_modes_in_later_frames(
-    mode, default_image, duplicate, tmp_path: Path
+    mode: str, default_image: bool, duplicate: bool, tmp_path: Path
 ) -> None:
     test_file = str(tmp_path / "temp.png")
 

Tests/test_file_container.py

@@ -64,7 +64,7 @@ def test_seek_mode_2() -> None:
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_read_n0(bytesmode) -> None:
+def test_read_n0(bytesmode: bool) -> None:
     # Arrange
     with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
         container = ContainerIO.ContainerIO(fh, 22, 100)
@@ -80,7 +80,7 @@ def test_read_n0(bytesmode) -> None:
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_read_n(bytesmode) -> None:
+def test_read_n(bytesmode: bool) -> None:
     # Arrange
     with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
         container = ContainerIO.ContainerIO(fh, 22, 100)
@@ -96,7 +96,7 @@ def test_read_n(bytesmode) -> None:
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_read_eof(bytesmode) -> None:
+def test_read_eof(bytesmode: bool) -> None:
     # Arrange
     with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
         container = ContainerIO.ContainerIO(fh, 22, 100)
@@ -112,7 +112,7 @@ def test_read_eof(bytesmode) -> None:
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_readline(bytesmode) -> None:
+def test_readline(bytesmode: bool) -> None:
     # Arrange
     with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
         container = ContainerIO.ContainerIO(fh, 0, 120)
@@ -127,7 +127,7 @@ def test_readline(bytesmode) -> None:
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_readlines(bytesmode) -> None:
+def test_readlines(bytesmode: bool) -> None:
     # Arrange
     expected = [
         "This is line 1\n",

Tests/test_file_eps.py

@@ -84,7 +84,7 @@ simple_eps_file_with_long_binary_data = (
     ("filename", "size"), ((FILE1, (460, 352)), (FILE2, (360, 252)))
 )
 @pytest.mark.parametrize("scale", (1, 2))
-def test_sanity(filename, size, scale) -> None:
+def test_sanity(filename: str, size: tuple[int, int], scale: int) -> None:
     expected_size = tuple(s * scale for s in size)
     with Image.open(filename) as image:
         image.load(scale=scale)
@@ -129,28 +129,28 @@ def test_binary_header_only() -> None:
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_missing_version_comment(prefix) -> None:
+def test_missing_version_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_without_version))
     with pytest.raises(SyntaxError):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_missing_boundingbox_comment(prefix) -> None:
+def test_missing_boundingbox_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_without_boundingbox))
     with pytest.raises(SyntaxError, match='EPS header missing "%%BoundingBox" comment'):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_invalid_boundingbox_comment(prefix) -> None:
+def test_invalid_boundingbox_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_invalid_boundingbox))
     with pytest.raises(OSError, match="cannot determine EPS bounding box"):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix) -> None:
+def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix: bytes) -> None:
     data = io.BytesIO(
         prefix + b"\n".join(simple_eps_file_with_invalid_boundingbox_valid_imagedata)
     )
@@ -161,21 +161,21 @@ def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix) -> None:
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_ascii_comment_too_long(prefix) -> None:
+def test_ascii_comment_too_long(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_ascii_comment))
     with pytest.raises(SyntaxError, match="not an EPS file"):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_long_binary_data(prefix) -> None:
+def test_long_binary_data(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_binary_data))
     EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_load_long_binary_data(prefix) -> None:
+def test_load_long_binary_data(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_binary_data))
     with Image.open(data) as img:
         img.load()
@@ -305,7 +305,7 @@ def test_render_scale2() -> None:
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("filename", (FILE1, FILE2, "Tests/images/illu10_preview.eps"))
-def test_resize(filename) -> None:
+def test_resize(filename: str) -> None:
     with Image.open(filename) as im:
         new_size = (100, 100)
         im = im.resize(new_size)
@@ -314,7 +314,7 @@ def test_resize(filename) -> None:
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("filename", (FILE1, FILE2))
-def test_thumbnail(filename) -> None:
+def test_thumbnail(filename: str) -> None:
     # Issue #619
     with Image.open(filename) as im:
         new_size = (100, 100)
@@ -335,7 +335,7 @@ def test_readline_psfile(tmp_path: Path) -> None:
     line_endings = ["\r\n", "\n", "\n\r", "\r"]
     strings = ["something", "else", "baz", "bif"]
 
-    def _test_readline(t, ending) -> None:
+    def _test_readline(t: EpsImagePlugin.PSFile, ending: str) -> None:
         ending = "Failure with line ending: %s" % (
             "".join("%s" % ord(s) for s in ending)
         )
@@ -344,13 +344,13 @@ def test_readline_psfile(tmp_path: Path) -> None:
         assert t.readline().strip("\r\n") == "baz", ending
         assert t.readline().strip("\r\n") == "bif", ending
 
-    def _test_readline_io_psfile(test_string, ending) -> None:
+    def _test_readline_io_psfile(test_string: str, ending: str) -> None:
         f = io.BytesIO(test_string.encode("latin-1"))
         with pytest.warns(DeprecationWarning):
             t = EpsImagePlugin.PSFile(f)
         _test_readline(t, ending)
 
-    def _test_readline_file_psfile(test_string, ending) -> None:
+    def _test_readline_file_psfile(test_string: str, ending: str) -> None:
         f = str(tmp_path / "temp.txt")
         with open(f, "wb") as w:
             w.write(test_string.encode("latin-1"))
@@ -376,7 +376,7 @@ def test_psfile_deprecation() -> None:
     "line_ending",
     (b"\r\n", b"\n", b"\n\r", b"\r"),
 )
-def test_readline(prefix, line_ending) -> None:
+def test_readline(prefix: bytes, line_ending: bytes) -> None:
     simple_file = prefix + line_ending.join(simple_eps_file_with_comments)
     data = io.BytesIO(simple_file)
     test_file = EpsImagePlugin.EpsImageFile(data)
@@ -394,7 +394,7 @@ def test_readline(prefix, line_ending) -> None:
         "Tests/images/illuCS6_preview.eps",
     ),
 )
-def test_open_eps(filename) -> None:
+def test_open_eps(filename: str) -> None:
     # https://github.com/python-pillow/Pillow/issues/1104
     with Image.open(filename) as img:
         assert img.mode == "RGB"
@@ -417,7 +417,7 @@ def test_emptyline() -> None:
     "test_file",
     ["Tests/images/timeout-d675703545fee17acab56e5fec644c19979175de.eps"],
 )
-def test_timeout(test_file) -> None:
+def test_timeout(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with pytest.raises(Image.UnidentifiedImageError):
             with Image.open(f):

Tests/test_file_gif.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import warnings
 from io import BytesIO
 from pathlib import Path
+from typing import Generator
 
 import pytest
 
@@ -144,13 +145,13 @@ def test_strategy() -> None:
 
 
 def test_optimize() -> None:
-    def test_grayscale(optimize):
+    def test_grayscale(optimize: int) -> int:
         im = Image.new("L", (1, 1), 0)
         filename = BytesIO()
         im.save(filename, "GIF", optimize=optimize)
         return len(filename.getvalue())
 
-    def test_bilevel(optimize):
+    def test_bilevel(optimize: int) -> int:
         im = Image.new("1", (1, 1), 0)
         test_file = BytesIO()
         im.save(test_file, "GIF", optimize=optimize)
@@ -178,7 +179,9 @@ def test_optimize() -> None:
         (4, 513, 256),
     ),
 )
-def test_optimize_correctness(colors, size, expected_palette_length) -> None:
+def test_optimize_correctness(
+    colors: int, size: int, expected_palette_length: int
+) -> None:
     # 256 color Palette image, posterize to > 128 and < 128 levels.
     # Size bigger and smaller than 512x512.
     # Check the palette for number of colors allocated.
@@ -297,7 +300,7 @@ def test_roundtrip_save_all_1(tmp_path: Path) -> None:
         ("Tests/images/dispose_bgnd_rgba.gif", "RGBA"),
     ),
 )
-def test_loading_multiple_palettes(path, mode) -> None:
+def test_loading_multiple_palettes(path: str, mode: str) -> None:
     with Image.open(path) as im:
         assert im.mode == "P"
         first_frame_colors = im.palette.colors.keys()
@@ -347,9 +350,9 @@ def test_palette_handling(tmp_path: Path) -> None:
 def test_palette_434(tmp_path: Path) -> None:
     # see https://github.com/python-pillow/Pillow/issues/434
 
-    def roundtrip(im, *args, **kwargs):
+    def roundtrip(im: Image.Image, **kwargs: bool) -> Image.Image:
         out = str(tmp_path / "temp.gif")
-        im.copy().save(out, *args, **kwargs)
+        im.copy().save(out, **kwargs)
         reloaded = Image.open(out)
 
         return reloaded
@@ -429,7 +432,7 @@ def test_seek_rewind() -> None:
         ("Tests/images/iss634.gif", 42),
     ),
 )
-def test_n_frames(path, n_frames) -> None:
+def test_n_frames(path: str, n_frames: int) -> None:
     # Test is_animated before n_frames
     with Image.open(path) as im:
         assert im.is_animated == (n_frames != 1)
@@ -541,7 +544,10 @@ def test_dispose_background_transparency() -> None:
         ),
     ),
 )
-def test_transparent_dispose(loading_strategy, expected_colors) -> None:
+def test_transparent_dispose(
+    loading_strategy: GifImagePlugin.LoadingStrategy,
+    expected_colors: tuple[tuple[int | tuple[int, int, int, int], ...]],
+) -> None:
     GifImagePlugin.LOADING_STRATEGY = loading_strategy
     try:
         with Image.open("Tests/images/transparent_dispose.gif") as img:
@@ -889,7 +895,9 @@ def test_identical_frames(tmp_path: Path) -> None:
         1500,
     ),
 )
-def test_identical_frames_to_single_frame(duration, tmp_path: Path) -> None:
+def test_identical_frames_to_single_frame(
+    duration: int | list[int], tmp_path: Path
+) -> None:
     out = str(tmp_path / "temp.gif")
     im_list = [
         Image.new("L", (100, 100), "#000"),
@@ -1049,7 +1057,7 @@ def test_retain_comment_in_subsequent_frames(tmp_path: Path) -> None:
 def test_version(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
-    def assert_version_after_save(im, version) -> None:
+    def assert_version_after_save(im: Image.Image, version: bytes) -> None:
         im.save(out)
         with Image.open(out) as reread:
             assert reread.info["version"] == version
@@ -1088,7 +1096,7 @@ def test_append_images(tmp_path: Path) -> None:
         assert reread.n_frames == 3
 
     # Tests appending using a generator
-    def im_generator(ims):
+    def im_generator(ims: list[Image.Image]) -> Generator[Image.Image, None, None]:
         yield from ims
 
     im.save(out, save_all=True, append_images=im_generator(ims))

Tests/test_file_jpeg.py

@@ -5,6 +5,7 @@ import re
 import warnings
 from io import BytesIO
 from pathlib import Path
+from typing import Any
 
 import pytest
 
@@ -42,7 +43,7 @@ TEST_FILE = "Tests/images/hopper.jpg"
 
 @skip_unless_feature("jpg")
 class TestFileJpeg:
-    def roundtrip(self, im, **options):
+    def roundtrip(self, im: Image.Image, **options: Any) -> Image.Image:
         out = BytesIO()
         im.save(out, "JPEG", **options)
         test_bytes = out.tell()
@@ -51,7 +52,7 @@ class TestFileJpeg:
         im.bytes = test_bytes  # for testing only
         return im
 
-    def gen_random_image(self, size, mode: str = "RGB"):
+    def gen_random_image(self, size: tuple[int, int], mode: str = "RGB") -> Image.Image:
         """Generates a very hard to compress file
         :param size: tuple
         :param mode: optional image mode
@@ -71,7 +72,7 @@ class TestFileJpeg:
             assert im.get_format_mimetype() == "image/jpeg"
 
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
-    def test_zero(self, size, tmp_path: Path) -> None:
+    def test_zero(self, size: tuple[int, int], tmp_path: Path) -> None:
         f = str(tmp_path / "temp.jpg")
         im = Image.new("RGB", size)
         with pytest.raises(ValueError):
@@ -108,13 +109,11 @@ class TestFileJpeg:
                     assert "comment" not in reloaded.info
 
             # Test that a comment argument overrides the default comment
-            for comment in ("Test comment text", b"Text comment text"):
+            for comment in ("Test comment text", b"Test comment text"):
                 out = BytesIO()
                 im.save(out, format="JPEG", comment=comment)
                 with Image.open(out) as reloaded:
-                    if not isinstance(comment, bytes):
+                    assert reloaded.info["comment"] == b"Test comment text"
-                        comment = comment.encode()
-                    assert reloaded.info["comment"] == comment
 
     def test_cmyk(self) -> None:
         # Test CMYK handling.  Thanks to Tim and Charlie for test data,
@@ -145,7 +144,7 @@ class TestFileJpeg:
             assert k > 0.9
 
     def test_rgb(self) -> None:
-        def getchannels(im):
+        def getchannels(im: Image.Image) -> tuple[int, int, int]:
             return tuple(v[0] for v in im.layer)
 
         im = hopper()
@@ -161,8 +160,8 @@ class TestFileJpeg:
         "test_image_path",
         [TEST_FILE, "Tests/images/pil_sample_cmyk.jpg"],
     )
-    def test_dpi(self, test_image_path) -> None:
+    def test_dpi(self, test_image_path: str) -> None:
-        def test(xdpi, ydpi=None):
+        def test(xdpi: int, ydpi: int | None = None):
             with Image.open(test_image_path) as im:
                 im = self.roundtrip(im, dpi=(xdpi, ydpi or xdpi))
             return im.info.get("dpi")
@@ -207,7 +206,7 @@ class TestFileJpeg:
             ImageFile.MAXBLOCK * 4 + 3,  # large block
         ),
     )
-    def test_icc_big(self, n) -> None:
+    def test_icc_big(self, n: int) -> None:
         # Make sure that the "extra" support handles large blocks
         # The ICC APP marker can store 65519 bytes per marker, so
         # using a 4-byte test code should allow us to detect out of
@@ -433,7 +432,7 @@ class TestFileJpeg:
         assert_image(im1, im2.mode, im2.size)
 
     def test_subsampling(self) -> None:
-        def getsampling(im):
+        def getsampling(im: Image.Image):
             layer = im.layer
             return layer[0][1:3] + layer[1][1:3] + layer[2][1:3]
 
@@ -530,7 +529,7 @@ class TestFileJpeg:
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
     def test_qtables(self, tmp_path: Path) -> None:
-        def _n_qtables_helper(n, test_file) -> None:
+        def _n_qtables_helper(n: int, test_file: str) -> None:
             with Image.open(test_file) as im:
                 f = str(tmp_path / "temp.jpg")
                 im.save(f, qtables=[[n] * 64] * n)
@@ -666,7 +665,7 @@ class TestFileJpeg:
         "blocks, rows, markers",
         ((0, 0, 0), (1, 0, 15), (3, 0, 5), (8, 0, 1), (0, 1, 3), (0, 2, 1)),
     )
-    def test_restart_markers(self, blocks, rows, markers) -> None:
+    def test_restart_markers(self, blocks: int, rows: int, markers: int) -> None:
         im = Image.new("RGB", (32, 32))  # 16 MCUs
         out = BytesIO()
         im.save(
@@ -724,13 +723,13 @@ class TestFileJpeg:
             assert im.format == "JPEG"
 
     @pytest.mark.parametrize("mode", ("1", "L", "RGB", "RGBX", "CMYK", "YCbCr"))
-    def test_save_correct_modes(self, mode) -> None:
+    def test_save_correct_modes(self, mode: str) -> None:
         out = BytesIO()
         img = Image.new(mode, (20, 20))
         img.save(out, "JPEG")
 
     @pytest.mark.parametrize("mode", ("LA", "La", "RGBA", "RGBa", "P"))
-    def test_save_wrong_modes(self, mode) -> None:
+    def test_save_wrong_modes(self, mode: str) -> None:
         # ref https://github.com/python-pillow/Pillow/issues/2005
         out = BytesIO()
         img = Image.new(mode, (20, 20))
@@ -982,12 +981,12 @@ class TestFileJpeg:
         # Even though this decoder never says that it is finished
         # the image should still end when there is no new data
         class InfiniteMockPyDecoder(ImageFile.PyDecoder):
-            def decode(self, buffer):
+            def decode(self, buffer: bytes) -> tuple[int, int]:
                 return 0, 0
 
         decoder = InfiniteMockPyDecoder(None)
 
-        def closure(mode, *args):
+        def closure(mode: str, *args) -> InfiniteMockPyDecoder:
             decoder.__init__(mode, *args)
             return decoder
 

Tests/test_file_jpeg2k.py

@@ -4,6 +4,7 @@ import os
 import re
 from io import BytesIO
 from pathlib import Path
+from typing import Any
 
 import pytest
 
@@ -36,7 +37,7 @@ test_card.load()
 # 'Not enough memory to handle tile data'
 
 
-def roundtrip(im, **options):
+def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "JPEG2000", **options)
     test_bytes = out.tell()
@@ -138,7 +139,7 @@ def test_prog_res_rt() -> None:
 
 
 @pytest.mark.parametrize("num_resolutions", range(2, 6))
-def test_default_num_resolutions(num_resolutions) -> None:
+def test_default_num_resolutions(num_resolutions: int) -> None:
     d = 1 << (num_resolutions - 1)
     im = test_card.resize((d - 1, d - 1))
     with pytest.raises(OSError):
@@ -198,9 +199,9 @@ def test_layers_type(tmp_path: Path) -> None:
     for quality_layers in [[100, 50, 10], (100, 50, 10), None]:
         test_card.save(outfile, quality_layers=quality_layers)
 
-    for quality_layers in ["quality_layers", ("100", "50", "10")]:
+    for quality_layers_str in ["quality_layers", ("100", "50", "10")]:
         with pytest.raises(ValueError):
-            test_card.save(outfile, quality_layers=quality_layers)
+            test_card.save(outfile, quality_layers=quality_layers_str)
 
 
 def test_layers() -> None:
@@ -233,7 +234,7 @@ def test_layers() -> None:
         ("foo.jp2", {"no_jp2": False}, 4, b"jP"),
     ),
 )
-def test_no_jp2(name, args, offset, data) -> None:
+def test_no_jp2(name: str, args: dict[str, bool], offset: int, data: bytes) -> None:
     out = BytesIO()
     if name:
         out.name = name
@@ -278,7 +279,7 @@ def test_sgnd(tmp_path: Path) -> None:
 
 
 @pytest.mark.parametrize("ext", (".j2k", ".jp2"))
-def test_rgba(ext) -> None:
+def test_rgba(ext: str) -> None:
     # Arrange
     with Image.open("Tests/images/rgb_trns_ycbc" + ext) as im:
         # Act
@@ -289,7 +290,7 @@ def test_rgba(ext) -> None:
 
 
 @pytest.mark.parametrize("ext", (".j2k", ".jp2"))
-def test_16bit_monochrome_has_correct_mode(ext) -> None:
+def test_16bit_monochrome_has_correct_mode(ext: str) -> None:
     with Image.open("Tests/images/16bit.cropped" + ext) as im:
         im.load()
         assert im.mode == "I;16"
@@ -346,12 +347,12 @@ def test_parser_feed() -> None:
     not os.path.exists(EXTRA_DIR), reason="Extra image files not installed"
 )
 @pytest.mark.parametrize("name", ("subsampling_1", "subsampling_2", "zoo1", "zoo2"))
-def test_subsampling_decode(name) -> None:
+def test_subsampling_decode(name: str) -> None:
     test = f"{EXTRA_DIR}/{name}.jp2"
     reference = f"{EXTRA_DIR}/{name}.ppm"
 
     with Image.open(test) as im:
-        epsilon = 3  # for YCbCr images
+        epsilon = 3.0  # for YCbCr images
         with Image.open(reference) as im2:
             width, height = im2.size
             if name[-1] == "2":
@@ -400,7 +401,7 @@ def test_save_comment() -> None:
         "Tests/images/crash-d2c93af851d3ab9a19e34503626368b2ecde9c03.j2k",
     ],
 )
-def test_crashes(test_file) -> None:
+def test_crashes(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             # Valgrind should not complain here

Tests/test_file_libtiff.py

@@ -27,7 +27,7 @@ from .helper import (
 
 @skip_unless_feature("libtiff")
 class LibTiffTestCase:
-    def _assert_noerr(self, tmp_path: Path, im) -> None:
+    def _assert_noerr(self, tmp_path: Path, im: Image.Image) -> None:
         """Helper tests that assert basic sanity about the g4 tiff reading"""
         # 1 bit
         assert im.mode == "1"
@@ -140,7 +140,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
     @pytest.mark.parametrize("legacy_api", (False, True))
-    def test_write_metadata(self, legacy_api, tmp_path: Path) -> None:
+    def test_write_metadata(self, legacy_api: bool, tmp_path: Path) -> None:
         """Test metadata writing through libtiff"""
         f = str(tmp_path / "temp.tiff")
         with Image.open("Tests/images/hopper_g4.tif") as img:
@@ -243,7 +243,7 @@ class TestFileLibTiff(LibTiffTestCase):
         TiffImagePlugin.WRITE_LIBTIFF = False
 
     def test_custom_metadata(self, tmp_path: Path) -> None:
-        tc = namedtuple("test_case", "value,type,supported_by_default")
+        tc = namedtuple("tc", "value,type,supported_by_default")
         custom = {
             37000 + k: v
             for k, v in enumerate(
@@ -284,7 +284,9 @@ class TestFileLibTiff(LibTiffTestCase):
         for libtiff in libtiffs:
             TiffImagePlugin.WRITE_LIBTIFF = libtiff
 
-            def check_tags(tiffinfo) -> None:
+            def check_tags(
+                tiffinfo: TiffImagePlugin.ImageFileDirectory_v2 | dict[int, str]
+            ) -> None:
                 im = hopper()
 
                 out = str(tmp_path / "temp.tif")
@@ -502,7 +504,7 @@ class TestFileLibTiff(LibTiffTestCase):
         assert_image_equal_tofile(im, out)
 
     @pytest.mark.parametrize("im", (hopper("P"), Image.new("P", (1, 1), "#000")))
-    def test_palette_save(self, im, tmp_path: Path) -> None:
+    def test_palette_save(self, im: Image.Image, tmp_path: Path) -> None:
         out = str(tmp_path / "temp.tif")
 
         TiffImagePlugin.WRITE_LIBTIFF = True
@@ -514,7 +516,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert len(reloaded.tag_v2[320]) == 768
 
     @pytest.mark.parametrize("compression", ("tiff_ccitt", "group3", "group4"))
-    def test_bw_compression_w_rgb(self, compression, tmp_path: Path) -> None:
+    def test_bw_compression_w_rgb(self, compression: str, tmp_path: Path) -> None:
         im = hopper("RGB")
         out = str(tmp_path / "temp.tif")
 
@@ -647,7 +649,7 @@ class TestFileLibTiff(LibTiffTestCase):
         # Generate test image
         pilim = hopper()
 
-        def save_bytesio(compression=None) -> None:
+        def save_bytesio(compression: str | None = None) -> None:
             buffer_io = io.BytesIO()
             pilim.save(buffer_io, format="tiff", compression=compression)
             buffer_io.seek(0)
@@ -731,7 +733,7 @@ class TestFileLibTiff(LibTiffTestCase):
         assert icc == icc_libtiff
 
     def test_write_icc(self, tmp_path: Path) -> None:
-        def check_write(libtiff) -> None:
+        def check_write(libtiff: bool) -> None:
             TiffImagePlugin.WRITE_LIBTIFF = libtiff
 
             with Image.open("Tests/images/hopper.iccprofile.tif") as img:
@@ -837,7 +839,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert reloaded.mode == "F"
             assert reloaded.getexif()[SAMPLEFORMAT] == 3
 
-    def test_lzma(self, capfd):
+    def test_lzma(self, capfd: pytest.CaptureFixture[str]) -> None:
         try:
             with Image.open("Tests/images/hopper_lzma.tif") as im:
                 assert im.mode == "RGB"
@@ -853,7 +855,7 @@ class TestFileLibTiff(LibTiffTestCase):
             sys.stderr.write(captured.err)
             raise
 
-    def test_webp(self, capfd):
+    def test_webp(self, capfd: pytest.CaptureFixture[str]) -> None:
         try:
             with Image.open("Tests/images/hopper_webp.tif") as im:
                 assert im.mode == "RGB"
@@ -971,7 +973,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGBa_target.png")
 
     @pytest.mark.parametrize("compression", (None, "jpeg"))
-    def test_block_tile_tags(self, compression, tmp_path: Path) -> None:
+    def test_block_tile_tags(self, compression: str | None, tmp_path: Path) -> None:
         im = hopper()
         out = str(tmp_path / "temp.tif")
 
@@ -1020,7 +1022,9 @@ class TestFileLibTiff(LibTiffTestCase):
             ),
         ],
     )
-    def test_wrong_bits_per_sample(self, file_name, mode, size, tile) -> None:
+    def test_wrong_bits_per_sample(
+        self, file_name: str, mode: str, size: tuple[int, int], tile
+    ) -> None:
         with Image.open("Tests/images/" + file_name) as im:
             assert im.mode == mode
             assert im.size == size
@@ -1086,7 +1090,7 @@ class TestFileLibTiff(LibTiffTestCase):
         TiffImagePlugin.READ_LIBTIFF = False
 
     @pytest.mark.parametrize("compression", ("tiff_adobe_deflate", "jpeg"))
-    def test_save_multistrip(self, compression, tmp_path: Path) -> None:
+    def test_save_multistrip(self, compression: str, tmp_path: Path) -> None:
         im = hopper("RGB").resize((256, 256))
         out = str(tmp_path / "temp.tif")
         im.save(out, compression=compression)
@@ -1096,14 +1100,14 @@ class TestFileLibTiff(LibTiffTestCase):
             assert len(im.tag_v2[STRIPOFFSETS]) > 1
 
     @pytest.mark.parametrize("argument", (True, False))
-    def test_save_single_strip(self, argument, tmp_path: Path) -> None:
+    def test_save_single_strip(self, argument: bool, tmp_path: Path) -> None:
         im = hopper("RGB").resize((256, 256))
         out = str(tmp_path / "temp.tif")
 
         if not argument:
             TiffImagePlugin.STRIP_SIZE = 2**18
         try:
-            arguments = {"compression": "tiff_adobe_deflate"}
+            arguments: dict[str, str | int] = {"compression": "tiff_adobe_deflate"}
             if argument:
                 arguments["strip_size"] = 2**18
             im.save(out, **arguments)
@@ -1114,7 +1118,7 @@ class TestFileLibTiff(LibTiffTestCase):
             TiffImagePlugin.STRIP_SIZE = 65536
 
     @pytest.mark.parametrize("compression", ("tiff_adobe_deflate", None))
-    def test_save_zero(self, compression, tmp_path: Path) -> None:
+    def test_save_zero(self, compression: str | None, tmp_path: Path) -> None:
         im = Image.new("RGB", (0, 0))
         out = str(tmp_path / "temp.tif")
         with pytest.raises(SystemError):
@@ -1134,7 +1138,7 @@ class TestFileLibTiff(LibTiffTestCase):
             ("Tests/images/child_ifd_jpeg.tiff", (20,)),
         ),
     )
-    def test_get_child_images(self, path, sizes) -> None:
+    def test_get_child_images(self, path: str, sizes: tuple[int, ...]) -> None:
         with Image.open(path) as im:
             ims = im.get_child_images()
 

Tests/test_file_mpo.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import warnings
 from io import BytesIO
+from typing import Any
 
 import pytest
 
@@ -19,7 +20,7 @@ test_files = ["Tests/images/sugarshack.mpo", "Tests/images/frozenpond.mpo"]
 pytestmark = skip_unless_feature("jpg")
 
 
-def roundtrip(im, **options):
+def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "MPO", **options)
     test_bytes = out.tell()
@@ -30,7 +31,7 @@ def roundtrip(im, **options):
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_sanity(test_file) -> None:
+def test_sanity(test_file: str) -> None:
     with Image.open(test_file) as im:
         im.load()
         assert im.mode == "RGB"
@@ -70,7 +71,7 @@ def test_context_manager() -> None:
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_app(test_file) -> None:
+def test_app(test_file: str) -> None:
     # Test APP/COM reader (@PIL135)
     with Image.open(test_file) as im:
         assert im.applist[0][0] == "APP1"
@@ -82,7 +83,7 @@ def test_app(test_file) -> None:
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_exif(test_file) -> None:
+def test_exif(test_file: str) -> None:
     with Image.open(test_file) as im_original:
         im_reloaded = roundtrip(im_original, save_all=True, exif=im_original.getexif())
 
@@ -143,7 +144,7 @@ def test_reload_exif_after_seek() -> None:
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_mp(test_file) -> None:
+def test_mp(test_file: str) -> None:
     with Image.open(test_file) as im:
         mpinfo = im._getmp()
         assert mpinfo[45056] == b"0100"
@@ -168,7 +169,7 @@ def test_mp_no_data() -> None:
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_mp_attribute(test_file) -> None:
+def test_mp_attribute(test_file: str) -> None:
     with Image.open(test_file) as im:
         mpinfo = im._getmp()
     for frame_number, mpentry in enumerate(mpinfo[0xB002]):
@@ -185,7 +186,7 @@ def test_mp_attribute(test_file) -> None:
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_seek(test_file) -> None:
+def test_seek(test_file: str) -> None:
     with Image.open(test_file) as im:
         assert im.tell() == 0
         # prior to first image raises an error, both blatant and borderline
@@ -229,7 +230,7 @@ def test_eoferror() -> None:
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_image_grab(test_file) -> None:
+def test_image_grab(test_file: str) -> None:
     with Image.open(test_file) as im:
         assert im.tell() == 0
         im0 = im.tobytes()
@@ -244,7 +245,7 @@ def test_image_grab(test_file) -> None:
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_save(test_file) -> None:
+def test_save(test_file: str) -> None:
     with Image.open(test_file) as im:
         assert im.tell() == 0
         jpg0 = roundtrip(im)

Tests/test_file_png.py

@@ -6,6 +6,7 @@ import warnings
 import zlib
 from io import BytesIO
 from pathlib import Path
+from typing import Any
 
 import pytest
 
@@ -36,7 +37,7 @@ TEST_PNG_FILE = "Tests/images/hopper.png"
 MAGIC = PngImagePlugin._MAGIC
 
 
-def chunk(cid, *data):
+def chunk(cid: bytes, *data: bytes) -> bytes:
     test_file = BytesIO()
     PngImagePlugin.putchunk(*(test_file, cid) + data)
     return test_file.getvalue()
@@ -52,11 +53,11 @@ HEAD = MAGIC + IHDR
 TAIL = IDAT + IEND
 
 
-def load(data):
+def load(data: bytes) -> Image.Image:
     return Image.open(BytesIO(data))
 
 
-def roundtrip(im, **options):
+def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "PNG", **options)
     out.seek(0)
@@ -65,7 +66,7 @@ def roundtrip(im, **options):
 
 @skip_unless_feature("zlib")
 class TestFilePng:
-    def get_chunks(self, filename):
+    def get_chunks(self, filename: str) -> list[bytes]:
         chunks = []
         with open(filename, "rb") as fp:
             fp.read(8)
@@ -436,7 +437,7 @@ class TestFilePng:
     def test_unicode_text(self) -> None:
         # Check preservation of non-ASCII characters
 
-        def rt_text(value) -> None:
+        def rt_text(value: str) -> None:
             im = Image.new("RGB", (32, 32))
             info = PngImagePlugin.PngInfo()
             info.add_text("Text", value)
@@ -636,7 +637,7 @@ class TestFilePng:
     @pytest.mark.parametrize(
         "cid", (b"IHDR", b"sRGB", b"pHYs", b"acTL", b"fcTL", b"fdAT")
     )
-    def test_truncated_chunks(self, cid) -> None:
+    def test_truncated_chunks(self, cid: bytes) -> None:
         fp = BytesIO()
         with PngImagePlugin.PngStream(fp) as png:
             with pytest.raises(ValueError):
@@ -755,7 +756,7 @@ class TestFilePng:
                 im.seek(1)
 
     @pytest.mark.parametrize("buffer", (True, False))
-    def test_save_stdout(self, buffer) -> None:
+    def test_save_stdout(self, buffer: bool) -> None:
         old_stdout = sys.stdout
 
         if buffer:

Tests/test_file_ppm.py

@@ -70,7 +70,9 @@ def test_sanity() -> None:
         ),
     ),
 )
-def test_arbitrary_maxval(data, mode, pixels) -> None:
+def test_arbitrary_maxval(
+    data: bytes, mode: str, pixels: tuple[int | tuple[int, int, int], ...]
+) -> None:
     fp = BytesIO(data)
     with Image.open(fp) as im:
         assert im.size == (3, 1)
@@ -139,7 +141,7 @@ def test_pfm_big_endian(tmp_path: Path) -> None:
         b"Pf 1 1 -0.0 \0\0\0\0",
     ],
 )
-def test_pfm_invalid(data) -> None:
+def test_pfm_invalid(data: bytes) -> None:
     with pytest.raises(ValueError):
         with Image.open(BytesIO(data)):
             pass
@@ -162,7 +164,7 @@ def test_pfm_invalid(data) -> None:
         ),
     ),
 )
-def test_plain(plain_path, raw_path) -> None:
+def test_plain(plain_path: str, raw_path: str) -> None:
     with Image.open(plain_path) as im:
         assert_image_equal_tofile(im, raw_path)
 
@@ -186,7 +188,9 @@ def test_16bit_plain_pgm() -> None:
         (b"P3\n2 2\n255", b"0 0 0 001 1 1 2 2 2 255 255 255", 10**6),
     ),
 )
-def test_plain_data_with_comment(tmp_path: Path, header, data, comment_count) -> None:
+def test_plain_data_with_comment(
+    tmp_path: Path, header: bytes, data: bytes, comment_count: int
+) -> None:
     path1 = str(tmp_path / "temp1.ppm")
     path2 = str(tmp_path / "temp2.ppm")
     comment = b"# comment" * comment_count
@@ -199,7 +203,7 @@ def test_plain_data_with_comment(tmp_path: Path, header, data, comment_count) ->
 
 
 @pytest.mark.parametrize("data", (b"P1\n128 128\n", b"P3\n128 128\n255\n"))
-def test_plain_truncated_data(tmp_path: Path, data) -> None:
+def test_plain_truncated_data(tmp_path: Path, data: bytes) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(data)
@@ -210,7 +214,7 @@ def test_plain_truncated_data(tmp_path: Path, data) -> None:
 
 
 @pytest.mark.parametrize("data", (b"P1\n128 128\n1009", b"P3\n128 128\n255\n100A"))
-def test_plain_invalid_data(tmp_path: Path, data) -> None:
+def test_plain_invalid_data(tmp_path: Path, data: bytes) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(data)
@@ -227,7 +231,7 @@ def test_plain_invalid_data(tmp_path: Path, data) -> None:
         b"P3\n128 128\n255\n012345678910 0",  # token too long
     ),
 )
-def test_plain_ppm_token_too_long(tmp_path: Path, data) -> None:
+def test_plain_ppm_token_too_long(tmp_path: Path, data: bytes) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(data)
@@ -313,7 +317,7 @@ def test_not_enough_image_data(tmp_path: Path) -> None:
 
 
 @pytest.mark.parametrize("maxval", (b"0", b"65536"))
-def test_invalid_maxval(maxval, tmp_path: Path) -> None:
+def test_invalid_maxval(maxval: bytes, tmp_path: Path) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(b"P6\n3 1 " + maxval)
@@ -351,7 +355,7 @@ def test_mimetypes(tmp_path: Path) -> None:
 
 
 @pytest.mark.parametrize("buffer", (True, False))
-def test_save_stdout(buffer) -> None:
+def test_save_stdout(buffer: bool) -> None:
     old_stdout = sys.stdout
 
     if buffer:

Tests/test_file_sgi.py

@@ -72,7 +72,7 @@ def test_invalid_file() -> None:
 
 
 def test_write(tmp_path: Path) -> None:
-    def roundtrip(img) -> None:
+    def roundtrip(img: Image.Image) -> None:
         out = str(tmp_path / "temp.sgi")
         img.save(out, format="sgi")
         assert_image_equal_tofile(img, out)

Tests/test_image.py

@@ -162,8 +162,6 @@ class TestImage:
                 pass
 
     def test_pathlib(self, tmp_path: Path) -> None:
-        from PIL.Image import Path
-
         with Image.open(Path("Tests/images/multipage-mmap.tiff")) as im:
             assert im.mode == "P"
             assert im.size == (10, 10)

Tests/test_image_access.py

@@ -4,6 +4,7 @@ import os
 import subprocess
 import sys
 import sysconfig
+from types import ModuleType
 
 import pytest
 
@@ -23,6 +24,7 @@ else:
     except ImportError:
         cffi = None
 
+numpy: ModuleType | None
 try:
     import numpy
 except ImportError:
@@ -71,9 +73,10 @@ class TestImagePutPixel(AccessTest):
         pix1 = im1.load()
         pix2 = im2.load()
 
-        for x, y in ((0, "0"), ("0", 0)):
+        with pytest.raises(TypeError):
-            with pytest.raises(TypeError):
+            pix1[0, "0"]
-                pix1[x, y]
+        with pytest.raises(TypeError):
+            pix1["0", 0]
 
         for y in range(im1.size[1]):
             for x in range(im1.size[0]):
@@ -123,12 +126,13 @@ class TestImagePutPixel(AccessTest):
         im = hopper()
         pix = im.load()
 
+        assert numpy is not None
         assert pix[numpy.int32(1), numpy.int32(2)] == (18, 20, 59)
 
 
 class TestImageGetPixel(AccessTest):
     @staticmethod
-    def color(mode):
+    def color(mode: str) -> int | tuple[int, ...]:
         bands = Image.getmodebands(mode)
         if bands == 1:
             return 1
@@ -138,12 +142,13 @@ class TestImageGetPixel(AccessTest):
             return (16, 32, 49)
         return tuple(range(1, bands + 1))
 
-    def check(self, mode, expected_color=None) -> None:
+    def check(self, mode: str, expected_color_int: int | None = None) -> None:
         if self._need_cffi_access and mode.startswith("BGR;"):
             pytest.skip("Support not added to deprecated module for BGR;* modes")
 
-        if not expected_color:
+        expected_color = (
-            expected_color = self.color(mode)
+            self.color(mode) if expected_color_int is None else expected_color_int
+        )
 
         # check putpixel
         im = Image.new(mode, (1, 1), None)
@@ -222,7 +227,7 @@ class TestImageGetPixel(AccessTest):
             "YCbCr",
         ),
     )
-    def test_basic(self, mode) -> None:
+    def test_basic(self, mode: str) -> None:
         self.check(mode)
 
     def test_list(self) -> None:
@@ -231,14 +236,14 @@ class TestImageGetPixel(AccessTest):
 
     @pytest.mark.parametrize("mode", ("I;16", "I;16B"))
     @pytest.mark.parametrize("expected_color", (2**15 - 1, 2**15, 2**15 + 1, 2**16 - 1))
-    def test_signedness(self, mode, expected_color) -> None:
+    def test_signedness(self, mode: str, expected_color: int) -> None:
         # see https://github.com/python-pillow/Pillow/issues/452
         # pixelaccess is using signed int* instead of uint*
         self.check(mode, expected_color)
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
     @pytest.mark.parametrize("color", ((255, 0, 0), (255, 0, 0, 255)))
-    def test_p_putpixel_rgb_rgba(self, mode, color) -> None:
+    def test_p_putpixel_rgb_rgba(self, mode: str, color: tuple[int, ...]) -> None:
         im = Image.new(mode, (1, 1))
         im.putpixel((0, 0), color)
 
@@ -262,7 +267,7 @@ class TestCffiGetPixel(TestImageGetPixel):
 class TestCffi(AccessTest):
     _need_cffi_access = True
 
-    def _test_get_access(self, im) -> None:
+    def _test_get_access(self, im: Image.Image) -> None:
         """Do we get the same thing as the old pixel access
 
         Using private interfaces, forcing a capi access and
@@ -299,7 +304,7 @@ class TestCffi(AccessTest):
         # im = Image.new('I;32B', (10, 10), 2**10)
         # self._test_get_access(im)
 
-    def _test_set_access(self, im, color) -> None:
+    def _test_set_access(self, im: Image.Image, color: tuple[int, ...] | float) -> None:
         """Are we writing the correct bits into the image?
 
         Using private interfaces, forcing a capi access and
@@ -359,7 +364,7 @@ class TestCffi(AccessTest):
                 assert px[i, 0] == 0
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
-    def test_p_putpixel_rgb_rgba(self, mode) -> None:
+    def test_p_putpixel_rgb_rgba(self, mode: str) -> None:
         for color in ((255, 0, 0), (255, 0, 0, 127 if mode == "PA" else 255)):
             im = Image.new(mode, (1, 1))
             with pytest.warns(DeprecationWarning):
@@ -377,7 +382,7 @@ class TestImagePutPixelError(AccessTest):
     INVALID_TYPES = ["foo", 1.0, None]
 
     @pytest.mark.parametrize("mode", IMAGE_MODES1)
-    def test_putpixel_type_error1(self, mode) -> None:
+    def test_putpixel_type_error1(self, mode: str) -> None:
         im = hopper(mode)
         for v in self.INVALID_TYPES:
             with pytest.raises(TypeError, match="color must be int or tuple"):
@@ -400,14 +405,16 @@ class TestImagePutPixelError(AccessTest):
             ),
         ),
     )
-    def test_putpixel_invalid_number_of_bands(self, mode, band_numbers, match) -> None:
+    def test_putpixel_invalid_number_of_bands(
+        self, mode: str, band_numbers: tuple[int, ...], match: str
+    ) -> None:
         im = hopper(mode)
         for band_number in band_numbers:
             with pytest.raises(TypeError, match=match):
                 im.putpixel((0, 0), (0,) * band_number)
 
     @pytest.mark.parametrize("mode", IMAGE_MODES2)
-    def test_putpixel_type_error2(self, mode) -> None:
+    def test_putpixel_type_error2(self, mode: str) -> None:
         im = hopper(mode)
         for v in self.INVALID_TYPES:
             with pytest.raises(
@@ -416,7 +423,7 @@ class TestImagePutPixelError(AccessTest):
                 im.putpixel((0, 0), v)
 
     @pytest.mark.parametrize("mode", IMAGE_MODES1 + IMAGE_MODES2)
-    def test_putpixel_overflow_error(self, mode) -> None:
+    def test_putpixel_overflow_error(self, mode: str) -> None:
         im = hopper(mode)
         with pytest.raises(OverflowError):
             im.putpixel((0, 0), 2**80)
@@ -428,7 +435,7 @@ class TestEmbeddable:
     def test_embeddable(self) -> None:
         import ctypes
 
-        from setuptools.command.build_ext import new_compiler
+        from setuptools.command import build_ext
 
         with open("embed_pil.c", "w", encoding="utf-8") as fh:
             fh.write(
@@ -457,7 +464,7 @@ int main(int argc, char* argv[])
                 % sys.prefix.replace("\\", "\\\\")
             )
 
-        compiler = new_compiler()
+        compiler = getattr(build_ext, "new_compiler")()
         compiler.add_include_dir(sysconfig.get_config_var("INCLUDEPY"))
 
         libdir = sysconfig.get_config_var("LIBDIR") or sysconfig.get_config_var(
@@ -471,7 +478,7 @@ int main(int argc, char* argv[])
         env["PATH"] = sys.prefix + ";" + env["PATH"]
 
         # do not display the Windows Error Reporting dialog
-        ctypes.windll.kernel32.SetErrorMode(0x0002)
+        getattr(ctypes, "windll").kernel32.SetErrorMode(0x0002)
 
         process = subprocess.Popen(["embed_pil.exe"], env=env)
         process.communicate()

Tests/test_image_array.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from typing import Any
+
 import pytest
 from packaging.version import parse as parse_version
 
@@ -13,7 +15,7 @@ im = hopper().resize((128, 100))
 
 
 def test_toarray() -> None:
-    def test(mode):
+    def test(mode: str) -> tuple[tuple[int, ...], str, int]:
         ai = numpy.array(im.convert(mode))
         return ai.shape, ai.dtype.str, ai.nbytes
 
@@ -50,14 +52,14 @@ def test_fromarray() -> None:
     class Wrapper:
         """Class with API matching Image.fromarray"""
 
-        def __init__(self, img, arr_params) -> None:
+        def __init__(self, img: Image.Image, arr_params: dict[str, Any]) -> None:
             self.img = img
             self.__array_interface__ = arr_params
 
-        def tobytes(self):
+        def tobytes(self) -> bytes:
             return self.img.tobytes()
 
-    def test(mode):
+    def test(mode: str) -> tuple[str, tuple[int, int], bool]:
         i = im.convert(mode)
         a = numpy.array(i)
         # Make wrapper instance for image, new array interface

Tests/test_image_draft.py

@@ -7,7 +7,12 @@ from .helper import fromstring, skip_unless_feature, tostring
 pytestmark = skip_unless_feature("jpg")
 
 
-def draft_roundtrip(in_mode, in_size, req_mode, req_size):
+def draft_roundtrip(
+    in_mode: str,
+    in_size: tuple[int, int],
+    req_mode: str | None,
+    req_size: tuple[int, int] | None,
+) -> Image.Image:
     im = Image.new(in_mode, in_size)
     data = tostring(im, "JPEG")
     im = fromstring(data)

Tests/test_image_entropy.py

@@ -4,7 +4,7 @@ from .helper import hopper
 
 
 def test_entropy() -> None:
-    def entropy(mode):
+    def entropy(mode: str) -> float:
         return hopper(mode).entropy()
 
     assert round(abs(entropy("1") - 0.9138803254693582), 7) == 0

Tests/test_image_filter.py

@@ -36,7 +36,7 @@ from .helper import assert_image_equal, hopper
     ),
 )
 @pytest.mark.parametrize("mode", ("L", "I", "RGB", "CMYK"))
-def test_sanity(filter_to_apply, mode) -> None:
+def test_sanity(filter_to_apply: ImageFilter.Filter, mode: str) -> None:
     im = hopper(mode)
     if mode != "I" or isinstance(filter_to_apply, ImageFilter.BuiltinFilter):
         out = im.filter(filter_to_apply)
@@ -45,7 +45,7 @@ def test_sanity(filter_to_apply, mode) -> None:
 
 
 @pytest.mark.parametrize("mode", ("L", "I", "RGB", "CMYK"))
-def test_sanity_error(mode) -> None:
+def test_sanity_error(mode: str) -> None:
     with pytest.raises(TypeError):
         im = hopper(mode)
         im.filter("hello")
@@ -53,7 +53,7 @@ def test_sanity_error(mode) -> None:
 
 # crashes on small images
 @pytest.mark.parametrize("size", ((1, 1), (2, 2), (3, 3)))
-def test_crash(size) -> None:
+def test_crash(size: tuple[int, int]) -> None:
     im = Image.new("RGB", size)
     im.filter(ImageFilter.SMOOTH)
 
@@ -67,7 +67,10 @@ def test_crash(size) -> None:
         ("RGB", ((4, 0, 0), (0, 0, 0))),
     ),
 )
-def test_modefilter(mode, expected) -> None:
+def test_modefilter(
+    mode: str,
+    expected: tuple[int, int] | tuple[tuple[int, int, int], tuple[int, int, int]],
+) -> None:
     im = Image.new(mode, (3, 3), None)
     im.putdata(list(range(9)))
     # image is:
@@ -90,7 +93,13 @@ def test_modefilter(mode, expected) -> None:
         ("F", (0.0, 4.0, 8.0)),
     ),
 )
-def test_rankfilter(mode, expected) -> None:
+def test_rankfilter(
+    mode: str,
+    expected: (
+        tuple[float, float, float]
+        | tuple[tuple[int, int, int], tuple[int, int, int], tuple[int, int, int]]
+    ),
+) -> None:
     im = Image.new(mode, (3, 3), None)
     im.putdata(list(range(9)))
     # image is:
@@ -106,7 +115,7 @@ def test_rankfilter(mode, expected) -> None:
 @pytest.mark.parametrize(
     "filter", (ImageFilter.MinFilter, ImageFilter.MedianFilter, ImageFilter.MaxFilter)
 )
-def test_rankfilter_error(filter) -> None:
+def test_rankfilter_error(filter: ImageFilter.RankFilter) -> None:
     with pytest.raises(ValueError):
         im = Image.new("P", (3, 3), None)
         im.putdata(list(range(9)))
@@ -137,7 +146,7 @@ def test_kernel_not_enough_coefficients() -> None:
 
 
 @pytest.mark.parametrize("mode", ("L", "LA", "I", "RGB", "CMYK"))
-def test_consistency_3x3(mode) -> None:
+def test_consistency_3x3(mode: str) -> None:
     with Image.open("Tests/images/hopper.bmp") as source:
         reference_name = "hopper_emboss"
         reference_name += "_I.png" if mode == "I" else ".bmp"
@@ -163,7 +172,7 @@ def test_consistency_3x3(mode) -> None:
 
 
 @pytest.mark.parametrize("mode", ("L", "LA", "I", "RGB", "CMYK"))
-def test_consistency_5x5(mode) -> None:
+def test_consistency_5x5(mode: str) -> None:
     with Image.open("Tests/images/hopper.bmp") as source:
         reference_name = "hopper_emboss_more"
         reference_name += "_I.png" if mode == "I" else ".bmp"
@@ -199,7 +208,7 @@ def test_consistency_5x5(mode) -> None:
         (2, -2),
     ),
 )
-def test_invalid_box_blur_filter(radius) -> None:
+def test_invalid_box_blur_filter(radius: int | tuple[int, int]) -> None:
     with pytest.raises(ValueError):
         ImageFilter.BoxBlur(radius)
 

Tests/test_image_frombytes.py

@@ -8,7 +8,7 @@ from .helper import assert_image_equal, hopper
 
 
 @pytest.mark.parametrize("data_type", ("bytes", "memoryview"))
-def test_sanity(data_type) -> None:
+def test_sanity(data_type: str) -> None:
     im1 = hopper()
 
     data = im1.tobytes()

Tests/test_image_getextrema.py

@@ -6,7 +6,7 @@ from .helper import hopper
 
 
 def test_extrema() -> None:
-    def extrema(mode):
+    def extrema(mode: str) -> tuple[int, int] | tuple[tuple[int, int], ...]:
         return hopper(mode).getextrema()
 
     assert extrema("1") == (0, 255)

Tests/test_image_getpalette.py

@@ -6,7 +6,7 @@ from .helper import hopper
 
 
 def test_palette() -> None:
-    def palette(mode):
+    def palette(mode: str) -> list[int] | None:
         p = hopper(mode).getpalette()
         if p:
             return p[:10]

Tests/test_image_load.py

@@ -26,7 +26,7 @@ def test_close() -> None:
         im.getpixel((0, 0))
 
 
-def test_close_after_load(caplog) -> None:
+def test_close_after_load(caplog: pytest.LogCaptureFixture) -> None:
     im = Image.open("Tests/images/hopper.gif")
     im.load()
     with caplog.at_level(logging.DEBUG):

Tests/test_image_paste.py

@@ -11,10 +11,9 @@ class TestImagingPaste:
     masks = {}
     size = 128
 
-    def assert_9points_image(self, im, expected) -> None:
+    def assert_9points_image(
-        expected = [
+        self, im: Image.Image, expected: list[tuple[int, int, int, int]]
-            point[0] if im.mode == "L" else point[: len(im.mode)] for point in expected
+    ) -> None:
-        ]
         px = im.load()
         actual = [
             px[0, 0],
@@ -27,9 +26,17 @@ class TestImagingPaste:
             px[self.size // 2, self.size - 1],
             px[self.size - 1, self.size - 1],
         ]
-        assert actual == expected
+        assert actual == [
+            point[0] if im.mode == "L" else point[: len(im.mode)] for point in expected
+        ]
 
-    def assert_9points_paste(self, im, im2, mask, expected) -> None:
+    def assert_9points_paste(
+        self,
+        im: Image.Image,
+        im2: Image.Image,
+        mask: Image.Image,
+        expected: list[tuple[int, int, int, int]],
+    ) -> None:
         im3 = im.copy()
         im3.paste(im2, (0, 0), mask)
         self.assert_9points_image(im3, expected)
@@ -39,7 +46,7 @@ class TestImagingPaste:
         self.assert_9points_image(im, expected)
 
     @CachedProperty
-    def mask_1(self):
+    def mask_1(self) -> Image.Image:
         mask = Image.new("1", (self.size, self.size))
         px = mask.load()
         for y in range(mask.height):
@@ -48,11 +55,11 @@ class TestImagingPaste:
         return mask
 
     @CachedProperty
-    def mask_L(self):
+    def mask_L(self) -> Image.Image:
         return self.gradient_L.transpose(Image.Transpose.ROTATE_270)
 
     @CachedProperty
-    def gradient_L(self):
+    def gradient_L(self) -> Image.Image:
         gradient = Image.new("L", (self.size, self.size))
         px = gradient.load()
         for y in range(gradient.height):
@@ -61,7 +68,7 @@ class TestImagingPaste:
         return gradient
 
     @CachedProperty
-    def gradient_RGB(self):
+    def gradient_RGB(self) -> Image.Image:
         return Image.merge(
             "RGB",
             [
@@ -72,7 +79,7 @@ class TestImagingPaste:
         )
 
     @CachedProperty
-    def gradient_LA(self):
+    def gradient_LA(self) -> Image.Image:
         return Image.merge(
             "LA",
             [
@@ -82,7 +89,7 @@ class TestImagingPaste:
         )
 
     @CachedProperty
-    def gradient_RGBA(self):
+    def gradient_RGBA(self) -> Image.Image:
         return Image.merge(
             "RGBA",
             [
@@ -94,7 +101,7 @@ class TestImagingPaste:
         )
 
     @CachedProperty
-    def gradient_RGBa(self):
+    def gradient_RGBa(self) -> Image.Image:
         return Image.merge(
             "RGBa",
             [
@@ -106,7 +113,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_solid(self, mode) -> None:
+    def test_image_solid(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "red")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -116,7 +123,7 @@ class TestImagingPaste:
         assert_image_equal(im, im2)
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_1(self, mode) -> None:
+    def test_image_mask_1(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -138,7 +145,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_L(self, mode) -> None:
+    def test_image_mask_L(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -160,7 +167,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_LA(self, mode) -> None:
+    def test_image_mask_LA(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -182,7 +189,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_RGBA(self, mode) -> None:
+    def test_image_mask_RGBA(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -204,7 +211,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_RGBa(self, mode) -> None:
+    def test_image_mask_RGBa(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -226,7 +233,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_solid(self, mode) -> None:
+    def test_color_solid(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "black")
 
         rect = (12, 23, 128 + 12, 128 + 23)
@@ -239,7 +246,7 @@ class TestImagingPaste:
             assert sum(head[:255]) == 0
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_mask_1(self, mode) -> None:
+    def test_color_mask_1(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), (50, 60, 70, 80)[: len(mode)])
         color = (10, 20, 30, 40)[: len(mode)]
 
@@ -261,7 +268,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_mask_L(self, mode) -> None:
+    def test_color_mask_L(self, mode: str) -> None:
         im = getattr(self, "gradient_" + mode).copy()
         color = "white"
 
@@ -283,7 +290,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_mask_RGBA(self, mode) -> None:
+    def test_color_mask_RGBA(self, mode: str) -> None:
         im = getattr(self, "gradient_" + mode).copy()
         color = "white"
 
@@ -305,7 +312,7 @@ class TestImagingPaste:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_mask_RGBa(self, mode) -> None:
+    def test_color_mask_RGBa(self, mode: str) -> None:
         im = getattr(self, "gradient_" + mode).copy()
         color = "white"
 

Tests/test_image_putdata.py

@@ -31,7 +31,7 @@ def test_sanity() -> None:
 
 def test_long_integers() -> None:
     # see bug-200802-systemerror
-    def put(value):
+    def put(value: int) -> tuple[int, int, int, int]:
         im = Image.new("RGBA", (1, 1))
         im.putdata([value])
         return im.getpixel((0, 0))
@@ -58,7 +58,7 @@ def test_mode_with_L_with_float() -> None:
 
 
 @pytest.mark.parametrize("mode", ("I", "I;16", "I;16L", "I;16B"))
-def test_mode_i(mode) -> None:
+def test_mode_i(mode: str) -> None:
     src = hopper("L")
     data = list(src.getdata())
     im = Image.new(mode, src.size, 0)
@@ -79,7 +79,7 @@ def test_mode_F() -> None:
 
 
 @pytest.mark.parametrize("mode", ("BGR;15", "BGR;16", "BGR;24"))
-def test_mode_BGR(mode) -> None:
+def test_mode_BGR(mode: str) -> None:
     data = [(16, 32, 49), (32, 32, 98)]
     im = Image.new(mode, (1, 2))
     im.putdata(data)

Tests/test_image_putpalette.py

@@ -8,7 +8,7 @@ from .helper import assert_image_equal, assert_image_equal_tofile, hopper
 
 
 def test_putpalette() -> None:
-    def palette(mode):
+    def palette(mode: str) -> str | tuple[str, list[int]]:
         im = hopper(mode).copy()
         im.putpalette(list(range(256)) * 3)
         p = im.getpalette()
@@ -81,7 +81,7 @@ def test_putpalette_with_alpha_values() -> None:
         ("RGBAX", (1, 2, 3, 4, 0)),
     ),
 )
-def test_rgba_palette(mode, palette) -> None:
+def test_rgba_palette(mode: str, palette: tuple[int, ...]) -> None:
     im = Image.new("P", (1, 1))
     im.putpalette(palette, mode)
     assert im.getpalette() == [1, 2, 3]

Tests/test_image_reduce.py

@@ -48,7 +48,7 @@ gradients_image.load()
         ((1, 3), (10, 4)),
     ),
 )
-def test_args_factor(size, expected) -> None:
+def test_args_factor(size: int | tuple[int, int], expected: tuple[int, int]) -> None:
     im = Image.new("L", (10, 10))
     assert expected == im.reduce(size).size
 
@@ -56,7 +56,7 @@ def test_args_factor(size, expected) -> None:
 @pytest.mark.parametrize(
     "size, expected_error", ((0, ValueError), (2.0, TypeError), ((0, 10), ValueError))
 )
-def test_args_factor_error(size, expected_error) -> None:
+def test_args_factor_error(size: float | tuple[int, int], expected_error) -> None:
     im = Image.new("L", (10, 10))
     with pytest.raises(expected_error):
         im.reduce(size)
@@ -69,7 +69,7 @@ def test_args_factor_error(size, expected_error) -> None:
         ((5, 5, 6, 6), (1, 1)),
     ),
 )
-def test_args_box(size, expected) -> None:
+def test_args_box(size: tuple[int, int, int, int], expected: tuple[int, int]) -> None:
     im = Image.new("L", (10, 10))
     assert expected == im.reduce(2, size).size
 
@@ -86,20 +86,20 @@ def test_args_box(size, expected) -> None:
         ((5, 0, 5, 10), ValueError),
     ),
 )
-def test_args_box_error(size, expected_error) -> None:
+def test_args_box_error(size: str | tuple[int, int, int, int], expected_error) -> None:
     im = Image.new("L", (10, 10))
     with pytest.raises(expected_error):
         im.reduce(2, size).size
 
 
 @pytest.mark.parametrize("mode", ("P", "1", "I;16"))
-def test_unsupported_modes(mode) -> None:
+def test_unsupported_modes(mode: str) -> None:
     im = Image.new("P", (10, 10))
     with pytest.raises(ValueError):
         im.reduce(3)
 
 
-def get_image(mode):
+def get_image(mode: str) -> Image.Image:
     mode_info = ImageMode.getmode(mode)
     if mode_info.basetype == "L":
         bands = [gradients_image]
@@ -119,7 +119,7 @@ def get_image(mode):
     return im.crop((0, 0, im.width, im.height - 5))
 
 
-def compare_reduce_with_box(im, factor) -> None:
+def compare_reduce_with_box(im: Image.Image, factor: int | tuple[int, int]) -> None:
     box = (11, 13, 146, 164)
     reduced = im.reduce(factor, box=box)
     reference = im.crop(box).reduce(factor)
@@ -127,7 +127,10 @@ def compare_reduce_with_box(im, factor) -> None:
 
 
 def compare_reduce_with_reference(
-    im, factor, average_diff: float = 0.4, max_diff: int = 1
+    im: Image.Image,
+    factor: int | tuple[int, int],
+    average_diff: float = 0.4,
+    max_diff: int = 1,
 ) -> None:
     """Image.reduce() should look very similar to Image.resize(BOX).
 
@@ -173,7 +176,9 @@ def compare_reduce_with_reference(
     assert_compare_images(reduced, reference, average_diff, max_diff)
 
 
-def assert_compare_images(a, b, max_average_diff, max_diff: int = 255) -> None:
+def assert_compare_images(
+    a: Image.Image, b: Image.Image, max_average_diff: float, max_diff: int = 255
+) -> None:
     assert a.mode == b.mode, f"got mode {repr(a.mode)}, expected {repr(b.mode)}"
     assert a.size == b.size, f"got size {repr(a.size)}, expected {repr(b.size)}"
 
@@ -201,20 +206,20 @@ def assert_compare_images(a, b, max_average_diff, max_diff: int = 255) -> None:
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_L(factor) -> None:
+def test_mode_L(factor: int | tuple[int, int]) -> None:
     im = get_image("L")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_LA(factor) -> None:
+def test_mode_LA(factor: int | tuple[int, int]) -> None:
     im = get_image("LA")
     compare_reduce_with_reference(im, factor, 0.8, 5)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_LA_opaque(factor) -> None:
+def test_mode_LA_opaque(factor: int | tuple[int, int]) -> None:
     im = get_image("LA")
     # With opaque alpha, an error should be way smaller.
     im.putalpha(Image.new("L", im.size, 255))
@@ -223,27 +228,27 @@ def test_mode_LA_opaque(factor) -> None:
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_La(factor) -> None:
+def test_mode_La(factor: int | tuple[int, int]) -> None:
     im = get_image("La")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_RGB(factor) -> None:
+def test_mode_RGB(factor: int | tuple[int, int]) -> None:
     im = get_image("RGB")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_RGBA(factor) -> None:
+def test_mode_RGBA(factor: int | tuple[int, int]) -> None:
     im = get_image("RGBA")
     compare_reduce_with_reference(im, factor, 0.8, 5)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_RGBA_opaque(factor) -> None:
+def test_mode_RGBA_opaque(factor: int | tuple[int, int]) -> None:
     im = get_image("RGBA")
     # With opaque alpha, an error should be way smaller.
     im.putalpha(Image.new("L", im.size, 255))
@@ -252,21 +257,21 @@ def test_mode_RGBA_opaque(factor) -> None:
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_RGBa(factor) -> None:
+def test_mode_RGBa(factor: int | tuple[int, int]) -> None:
     im = get_image("RGBa")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_I(factor) -> None:
+def test_mode_I(factor: int | tuple[int, int]) -> None:
     im = get_image("I")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_F(factor) -> None:
+def test_mode_F(factor: int | tuple[int, int]) -> None:
     im = get_image("F")
     compare_reduce_with_reference(im, factor, 0, 0)
     compare_reduce_with_box(im, factor)

Tests/test_image_resample.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from contextlib import contextmanager
+from typing import Generator
 
 import pytest
 
@@ -51,7 +52,7 @@ class TestImagingResampleVulnerability:
 
 
 class TestImagingCoreResampleAccuracy:
-    def make_case(self, mode, size, color):
+    def make_case(self, mode: str, size: tuple[int, int], color: int) -> Image.Image:
         """Makes a sample image with two dark and two bright squares.
         For example:
         e0 e0 1f 1f
@@ -66,7 +67,7 @@ class TestImagingCoreResampleAccuracy:
 
         return Image.merge(mode, [case] * len(mode))
 
-    def make_sample(self, data, size):
+    def make_sample(self, data: str, size: tuple[int, int]) -> Image.Image:
         """Restores a sample image from given data string which contains
         hex-encoded pixels from the top left fourth of a sample.
         """
@@ -83,7 +84,7 @@ class TestImagingCoreResampleAccuracy:
                 s_px[size[0] - x - 1, y] = 255 - val
         return sample
 
-    def check_case(self, case, sample) -> None:
+    def check_case(self, case: Image.Image, sample: Image.Image) -> None:
         s_px = sample.load()
         c_px = case.load()
         for y in range(case.size[1]):
@@ -95,7 +96,7 @@ class TestImagingCoreResampleAccuracy:
                     )
                     assert s_px[x, y] == c_px[x, y], message
 
-    def serialize_image(self, image):
+    def serialize_image(self, image: Image.Image) -> str:
         s_px = image.load()
         return "\n".join(
             " ".join(f"{s_px[x, y]:02x}" for x in range(image.size[0]))
@@ -103,7 +104,7 @@ class TestImagingCoreResampleAccuracy:
         )
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_box(self, mode) -> None:
+    def test_reduce_box(self, mode: str) -> None:
         case = self.make_case(mode, (8, 8), 0xE1)
         case = case.resize((4, 4), Image.Resampling.BOX)
         # fmt: off
@@ -114,7 +115,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_bilinear(self, mode) -> None:
+    def test_reduce_bilinear(self, mode: str) -> None:
         case = self.make_case(mode, (8, 8), 0xE1)
         case = case.resize((4, 4), Image.Resampling.BILINEAR)
         # fmt: off
@@ -125,7 +126,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_hamming(self, mode) -> None:
+    def test_reduce_hamming(self, mode: str) -> None:
         case = self.make_case(mode, (8, 8), 0xE1)
         case = case.resize((4, 4), Image.Resampling.HAMMING)
         # fmt: off
@@ -136,7 +137,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_bicubic(self, mode) -> None:
+    def test_reduce_bicubic(self, mode: str) -> None:
         case = self.make_case(mode, (12, 12), 0xE1)
         case = case.resize((6, 6), Image.Resampling.BICUBIC)
         # fmt: off
@@ -148,7 +149,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (6, 6)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_lanczos(self, mode) -> None:
+    def test_reduce_lanczos(self, mode: str) -> None:
         case = self.make_case(mode, (16, 16), 0xE1)
         case = case.resize((8, 8), Image.Resampling.LANCZOS)
         # fmt: off
@@ -161,7 +162,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (8, 8)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_box(self, mode) -> None:
+    def test_enlarge_box(self, mode: str) -> None:
         case = self.make_case(mode, (2, 2), 0xE1)
         case = case.resize((4, 4), Image.Resampling.BOX)
         # fmt: off
@@ -172,7 +173,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_bilinear(self, mode) -> None:
+    def test_enlarge_bilinear(self, mode: str) -> None:
         case = self.make_case(mode, (2, 2), 0xE1)
         case = case.resize((4, 4), Image.Resampling.BILINEAR)
         # fmt: off
@@ -183,7 +184,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_hamming(self, mode) -> None:
+    def test_enlarge_hamming(self, mode: str) -> None:
         case = self.make_case(mode, (2, 2), 0xE1)
         case = case.resize((4, 4), Image.Resampling.HAMMING)
         # fmt: off
@@ -194,7 +195,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_bicubic(self, mode) -> None:
+    def test_enlarge_bicubic(self, mode: str) -> None:
         case = self.make_case(mode, (4, 4), 0xE1)
         case = case.resize((8, 8), Image.Resampling.BICUBIC)
         # fmt: off
@@ -207,7 +208,7 @@ class TestImagingCoreResampleAccuracy:
             self.check_case(channel, self.make_sample(data, (8, 8)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_lanczos(self, mode) -> None:
+    def test_enlarge_lanczos(self, mode: str) -> None:
         case = self.make_case(mode, (6, 6), 0xE1)
         case = case.resize((12, 12), Image.Resampling.LANCZOS)
         data = (
@@ -230,11 +231,13 @@ class TestImagingCoreResampleAccuracy:
 
 
 class TestCoreResampleConsistency:
-    def make_case(self, mode, fill):
+    def make_case(
+        self, mode: str, fill: tuple[int, int, int] | float
+    ) -> tuple[Image.Image, tuple[int, ...]]:
         im = Image.new(mode, (512, 9), fill)
         return im.resize((9, 512), Image.Resampling.LANCZOS), im.load()[0, 0]
 
-    def run_case(self, case) -> None:
+    def run_case(self, case: tuple[Image.Image, Image.Image]) -> None:
         channel, color = case
         px = channel.load()
         for x in range(channel.size[0]):
@@ -265,7 +268,7 @@ class TestCoreResampleConsistency:
 
 
 class TestCoreResampleAlphaCorrect:
-    def make_levels_case(self, mode):
+    def make_levels_case(self, mode: str) -> Image.Image:
         i = Image.new(mode, (256, 16))
         px = i.load()
         for y in range(i.size[1]):
@@ -275,7 +278,7 @@ class TestCoreResampleAlphaCorrect:
                 px[x, y] = tuple(pix)
         return i
 
-    def run_levels_case(self, i) -> None:
+    def run_levels_case(self, i: Image.Image) -> None:
         px = i.load()
         for y in range(i.size[1]):
             used_colors = {px[x, y][0] for x in range(i.size[0])}
@@ -302,7 +305,9 @@ class TestCoreResampleAlphaCorrect:
         self.run_levels_case(case.resize((512, 32), Image.Resampling.BICUBIC))
         self.run_levels_case(case.resize((512, 32), Image.Resampling.LANCZOS))
 
-    def make_dirty_case(self, mode, clean_pixel, dirty_pixel):
+    def make_dirty_case(
+        self, mode: str, clean_pixel: tuple[int, ...], dirty_pixel: tuple[int, ...]
+    ) -> Image.Image:
         i = Image.new(mode, (64, 64), dirty_pixel)
         px = i.load()
         xdiv4 = i.size[0] // 4
@@ -312,7 +317,7 @@ class TestCoreResampleAlphaCorrect:
                 px[x + xdiv4, y + ydiv4] = clean_pixel
         return i
 
-    def run_dirty_case(self, i, clean_pixel) -> None:
+    def run_dirty_case(self, i: Image.Image, clean_pixel: tuple[int, ...]) -> None:
         px = i.load()
         for y in range(i.size[1]):
             for x in range(i.size[0]):
@@ -350,7 +355,7 @@ class TestCoreResampleAlphaCorrect:
 
 class TestCoreResamplePasses:
     @contextmanager
-    def count(self, diff):
+    def count(self, diff: int) -> Generator[None, None, None]:
         count = Image.core.get_stats()["new_count"]
         yield
         assert Image.core.get_stats()["new_count"] - count == diff
@@ -432,7 +437,7 @@ class TestCoreResampleBox:
             Image.Resampling.LANCZOS,
         ),
     )
-    def test_wrong_arguments(self, resample) -> None:
+    def test_wrong_arguments(self, resample: Image.Resampling) -> None:
         im = hopper()
         im.resize((32, 32), resample, (0, 0, im.width, im.height))
         im.resize((32, 32), resample, (20, 20, im.width, im.height))
@@ -459,8 +464,12 @@ class TestCoreResampleBox:
         with pytest.raises(ValueError, match="can't exceed"):
             im.resize((32, 32), resample, (0, 0, im.width, im.height + 1))
 
-    def resize_tiled(self, im, dst_size, xtiles, ytiles):
+    def resize_tiled(
-        def split_range(size, tiles):
+        self, im: Image.Image, dst_size: tuple[int, int], xtiles: int, ytiles: int
+    ) -> Image.Image:
+        def split_range(
+            size: int, tiles: int
+        ) -> Generator[tuple[int, int], None, None]:
             scale = size / tiles
             for i in range(tiles):
                 yield int(round(scale * i)), int(round(scale * (i + 1)))
@@ -518,7 +527,7 @@ class TestCoreResampleBox:
     @pytest.mark.parametrize(
         "resample", (Image.Resampling.NEAREST, Image.Resampling.BILINEAR)
     )
-    def test_formats(self, mode, resample) -> None:
+    def test_formats(self, mode: str, resample: Image.Resampling) -> None:
         im = hopper(mode)
         box = (20, 20, im.size[0] - 20, im.size[1] - 20)
         with_box = im.resize((32, 32), resample, box)
@@ -558,7 +567,7 @@ class TestCoreResampleBox:
     @pytest.mark.parametrize(
         "flt", (Image.Resampling.NEAREST, Image.Resampling.BICUBIC)
     )
-    def test_skip_horizontal(self, flt) -> None:
+    def test_skip_horizontal(self, flt: Image.Resampling) -> None:
         # Can skip resize for one dimension
         im = hopper()
 
@@ -581,7 +590,7 @@ class TestCoreResampleBox:
     @pytest.mark.parametrize(
         "flt", (Image.Resampling.NEAREST, Image.Resampling.BICUBIC)
     )
-    def test_skip_vertical(self, flt) -> None:
+    def test_skip_vertical(self, flt: Image.Resampling) -> None:
         # Can skip resize for one dimension
         im = hopper()
 

Tests/test_image_rotate.py

@@ -12,7 +12,13 @@ from .helper import (
 )
 
 
-def rotate(im, mode, angle, center=None, translate=None) -> None:
+def rotate(
+    im: Image.Image,
+    mode: str,
+    angle: int,
+    center: tuple[int, int] | None = None,
+    translate: tuple[int, int] | None = None,
+) -> None:
     out = im.rotate(angle, center=center, translate=translate)
     assert out.mode == mode
     assert out.size == im.size  # default rotate clips output
@@ -27,13 +33,13 @@ def rotate(im, mode, angle, center=None, translate=None) -> None:
 
 
 @pytest.mark.parametrize("mode", ("1", "P", "L", "RGB", "I", "F"))
-def test_mode(mode) -> None:
+def test_mode(mode: str) -> None:
     im = hopper(mode)
     rotate(im, mode, 45)
 
 
 @pytest.mark.parametrize("angle", (0, 90, 180, 270))
-def test_angle(angle) -> None:
+def test_angle(angle: int) -> None:
     with Image.open("Tests/images/test-card.png") as im:
         rotate(im, im.mode, angle)
 
@@ -42,7 +48,7 @@ def test_angle(angle) -> None:
 
 
 @pytest.mark.parametrize("angle", (0, 45, 90, 180, 270))
-def test_zero(angle) -> None:
+def test_zero(angle: int) -> None:
     im = Image.new("RGB", (0, 0))
     rotate(im, im.mode, angle)
 

Tests/test_image_thumbnail.py

@@ -111,7 +111,7 @@ def test_load_first_unless_jpeg() -> None:
     with Image.open("Tests/images/hopper.jpg") as im:
         draft = im.draft
 
-        def im_draft(mode, size):
+        def im_draft(mode: str, size: tuple[int, int]):
             result = draft(mode, size)
             assert result is not None
 

Tests/test_image_transform.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import math
+from typing import Callable
 
 import pytest
 
@@ -91,7 +92,7 @@ class TestImageTransform:
             ("LA", (76, 0)),
         ),
     )
-    def test_fill(self, mode, expected_pixel) -> None:
+    def test_fill(self, mode: str, expected_pixel: tuple[int, ...]) -> None:
         im = hopper(mode)
         (w, h) = im.size
         transformed = im.transform(
@@ -142,7 +143,9 @@ class TestImageTransform:
         assert_image_equal(blank, transformed.crop((w // 2, 0, w, h // 2)))
         assert_image_equal(blank, transformed.crop((0, h // 2, w // 2, h)))
 
-    def _test_alpha_premult(self, op) -> None:
+    def _test_alpha_premult(
+        self, op: Callable[[Image.Image, tuple[int, int]], Image.Image]
+    ) -> None:
         # create image with half white, half black,
         # with the black half transparent.
         # do op,
@@ -159,13 +162,13 @@ class TestImageTransform:
         assert 40 * 10 == hist[-1]
 
     def test_alpha_premult_resize(self) -> None:
-        def op(im, sz):
+        def op(im: Image.Image, sz: tuple[int, int]) -> Image.Image:
             return im.resize(sz, Image.Resampling.BILINEAR)
 
         self._test_alpha_premult(op)
 
     def test_alpha_premult_transform(self) -> None:
-        def op(im, sz):
+        def op(im: Image.Image, sz: tuple[int, int]) -> Image.Image:
             (w, h) = im.size
             return im.transform(
                 sz, Image.Transform.EXTENT, (0, 0, w, h), Image.Resampling.BILINEAR
@@ -173,7 +176,9 @@ class TestImageTransform:
 
         self._test_alpha_premult(op)
 
-    def _test_nearest(self, op, mode) -> None:
+    def _test_nearest(
+        self, op: Callable[[Image.Image, tuple[int, int]], Image.Image], mode: str
+    ) -> None:
         # create white image with half transparent,
         # do op,
         # the image should remain white with half transparent
@@ -196,15 +201,15 @@ class TestImageTransform:
         )
 
     @pytest.mark.parametrize("mode", ("RGBA", "LA"))
-    def test_nearest_resize(self, mode) -> None:
+    def test_nearest_resize(self, mode: str) -> None:
-        def op(im, sz):
+        def op(im: Image.Image, sz: tuple[int, int]) -> Image.Image:
             return im.resize(sz, Image.Resampling.NEAREST)
 
         self._test_nearest(op, mode)
 
     @pytest.mark.parametrize("mode", ("RGBA", "LA"))
-    def test_nearest_transform(self, mode) -> None:
+    def test_nearest_transform(self, mode: str) -> None:
-        def op(im, sz):
+        def op(im: Image.Image, sz: tuple[int, int]) -> Image.Image:
             (w, h) = im.size
             return im.transform(
                 sz, Image.Transform.EXTENT, (0, 0, w, h), Image.Resampling.NEAREST
@@ -227,7 +232,9 @@ class TestImageTransform:
         # Running by default, but I'd totally understand not doing it in
         # the future
 
-        pattern = [Image.new("RGBA", (1024, 1024), (a, a, a, a)) for a in range(1, 65)]
+        pattern: list[Image.Image] | None = [
+            Image.new("RGBA", (1024, 1024), (a, a, a, a)) for a in range(1, 65)
+        ]
 
         # Yeah. Watch some JIT optimize this out.
         pattern = None  # noqa: F841
@@ -240,7 +247,7 @@ class TestImageTransform:
                 im.transform((100, 100), None)
 
     @pytest.mark.parametrize("resample", (Image.Resampling.BOX, "unknown"))
-    def test_unknown_resampling_filter(self, resample) -> None:
+    def test_unknown_resampling_filter(self, resample: Image.Resampling | str) -> None:
         with hopper() as im:
             (w, h) = im.size
             with pytest.raises(ValueError):
@@ -250,7 +257,7 @@ class TestImageTransform:
 class TestImageTransformAffine:
     transform = Image.Transform.AFFINE
 
-    def _test_image(self):
+    def _test_image(self) -> Image.Image:
         im = hopper("RGB")
         return im.crop((10, 20, im.width - 10, im.height - 20))
 
@@ -263,7 +270,7 @@ class TestImageTransformAffine:
             (270, Image.Transpose.ROTATE_270),
         ),
     )
-    def test_rotate(self, deg, transpose) -> None:
+    def test_rotate(self, deg: int, transpose: Image.Transpose | None) -> None:
         im = self._test_image()
 
         angle = -math.radians(deg)
@@ -313,7 +320,13 @@ class TestImageTransformAffine:
             (Image.Resampling.BICUBIC, 1),
         ),
     )
-    def test_resize(self, scale, epsilon_scale, resample, epsilon) -> None:
+    def test_resize(
+        self,
+        scale: float,
+        epsilon_scale: float,
+        resample: Image.Resampling,
+        epsilon: int,
+    ) -> None:
         im = self._test_image()
 
         size_up = int(round(im.width * scale)), int(round(im.height * scale))
@@ -342,7 +355,14 @@ class TestImageTransformAffine:
             (Image.Resampling.BICUBIC, 1),
         ),
     )
-    def test_translate(self, x, y, epsilon_scale, resample, epsilon) -> None:
+    def test_translate(
+        self,
+        x: float,
+        y: float,
+        epsilon_scale: float,
+        resample: Image.Resampling,
+        epsilon: float,
+    ) -> None:
         im = self._test_image()
 
         size_up = int(round(im.width + x)), int(round(im.height + y))

Tests/test_imagedraw.py

@@ -6,6 +6,7 @@ import os.path
 import pytest
 
 from PIL import Image, ImageColor, ImageDraw, ImageFont, features
+from PIL._typing import Coords
 
 from .helper import (
     assert_image_equal,
@@ -74,7 +75,7 @@ def test_mode_mismatch() -> None:
 
 @pytest.mark.parametrize("bbox", BBOX)
 @pytest.mark.parametrize("start, end", ((0, 180), (0.5, 180.4)))
-def test_arc(bbox, start, end) -> None:
+def test_arc(bbox: Coords, start: float, end: float) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -87,7 +88,7 @@ def test_arc(bbox, start, end) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_arc_end_le_start(bbox) -> None:
+def test_arc_end_le_start(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -102,7 +103,7 @@ def test_arc_end_le_start(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_arc_no_loops(bbox) -> None:
+def test_arc_no_loops(bbox: Coords) -> None:
     # No need to go in loops
     # Arrange
     im = Image.new("RGB", (W, H))
@@ -118,7 +119,7 @@ def test_arc_no_loops(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_arc_width(bbox) -> None:
+def test_arc_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -131,7 +132,7 @@ def test_arc_width(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_arc_width_pieslice_large(bbox) -> None:
+def test_arc_width_pieslice_large(bbox: Coords) -> None:
     # Tests an arc with a large enough width that it is a pieslice
     # Arrange
     im = Image.new("RGB", (W, H))
@@ -145,7 +146,7 @@ def test_arc_width_pieslice_large(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_arc_width_fill(bbox) -> None:
+def test_arc_width_fill(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -158,7 +159,7 @@ def test_arc_width_fill(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_arc_width_non_whole_angle(bbox) -> None:
+def test_arc_width_non_whole_angle(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -200,7 +201,7 @@ def test_bitmap() -> None:
 
 @pytest.mark.parametrize("mode", ("RGB", "L"))
 @pytest.mark.parametrize("bbox", BBOX)
-def test_chord(mode, bbox) -> None:
+def test_chord(mode: str, bbox: Coords) -> None:
     # Arrange
     im = Image.new(mode, (W, H))
     draw = ImageDraw.Draw(im)
@@ -214,7 +215,7 @@ def test_chord(mode, bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_chord_width(bbox) -> None:
+def test_chord_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -227,7 +228,7 @@ def test_chord_width(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_chord_width_fill(bbox) -> None:
+def test_chord_width_fill(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -240,7 +241,7 @@ def test_chord_width_fill(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_chord_zero_width(bbox) -> None:
+def test_chord_zero_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -266,7 +267,7 @@ def test_chord_too_fat() -> None:
 
 @pytest.mark.parametrize("mode", ("RGB", "L"))
 @pytest.mark.parametrize("bbox", BBOX)
-def test_ellipse(mode, bbox) -> None:
+def test_ellipse(mode: str, bbox: Coords) -> None:
     # Arrange
     im = Image.new(mode, (W, H))
     draw = ImageDraw.Draw(im)
@@ -280,7 +281,7 @@ def test_ellipse(mode, bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_ellipse_translucent(bbox) -> None:
+def test_ellipse_translucent(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im, "RGBA")
@@ -317,7 +318,7 @@ def test_ellipse_symmetric() -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_ellipse_width(bbox) -> None:
+def test_ellipse_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -342,7 +343,7 @@ def test_ellipse_width_large() -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_ellipse_width_fill(bbox) -> None:
+def test_ellipse_width_fill(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -355,7 +356,7 @@ def test_ellipse_width_fill(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_ellipse_zero_width(bbox) -> None:
+def test_ellipse_zero_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -367,7 +368,7 @@ def test_ellipse_zero_width(bbox) -> None:
     assert_image_equal_tofile(im, "Tests/images/imagedraw_ellipse_zero_width.png")
 
 
-def ellipse_various_sizes_helper(filled):
+def ellipse_various_sizes_helper(filled: bool) -> Image.Image:
     ellipse_sizes = range(32)
     image_size = sum(ellipse_sizes) + len(ellipse_sizes) + 1
     im = Image.new("RGB", (image_size, image_size))
@@ -409,7 +410,7 @@ def test_ellipse_various_sizes_filled() -> None:
 
 
 @pytest.mark.parametrize("points", POINTS)
-def test_line(points) -> None:
+def test_line(points: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -482,7 +483,7 @@ def test_transform() -> None:
 
 @pytest.mark.parametrize("bbox", BBOX)
 @pytest.mark.parametrize("start, end", ((-92, 46), (-92.2, 46.2)))
-def test_pieslice(bbox, start, end) -> None:
+def test_pieslice(bbox: Coords, start: float, end: float) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -495,7 +496,7 @@ def test_pieslice(bbox, start, end) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_pieslice_width(bbox) -> None:
+def test_pieslice_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -508,7 +509,7 @@ def test_pieslice_width(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_pieslice_width_fill(bbox) -> None:
+def test_pieslice_width_fill(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -522,7 +523,7 @@ def test_pieslice_width_fill(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_pieslice_zero_width(bbox) -> None:
+def test_pieslice_zero_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -577,7 +578,7 @@ def test_pieslice_no_spikes() -> None:
 
 
 @pytest.mark.parametrize("points", POINTS)
-def test_point(points) -> None:
+def test_point(points: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -602,7 +603,7 @@ def test_point_I16() -> None:
 
 
 @pytest.mark.parametrize("points", POINTS)
-def test_polygon(points) -> None:
+def test_polygon(points: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -616,7 +617,9 @@ def test_polygon(points) -> None:
 
 @pytest.mark.parametrize("mode", ("RGB", "L"))
 @pytest.mark.parametrize("kite_points", KITE_POINTS)
-def test_polygon_kite(mode, kite_points) -> None:
+def test_polygon_kite(
+    mode: str, kite_points: tuple[tuple[int, int], ...] | list[tuple[int, int]]
+) -> None:
     # Test drawing lines of different gradients (dx>dy, dy>dx) and
     # vertical (dx==0) and horizontal (dy==0) lines
     # Arrange
@@ -673,7 +676,7 @@ def test_polygon_translucent() -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_rectangle(bbox) -> None:
+def test_rectangle(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -700,7 +703,7 @@ def test_big_rectangle() -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_rectangle_width(bbox) -> None:
+def test_rectangle_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -714,7 +717,7 @@ def test_rectangle_width(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_rectangle_width_fill(bbox) -> None:
+def test_rectangle_width_fill(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -728,7 +731,7 @@ def test_rectangle_width_fill(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_rectangle_zero_width(bbox) -> None:
+def test_rectangle_zero_width(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -741,7 +744,7 @@ def test_rectangle_zero_width(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_rectangle_I16(bbox) -> None:
+def test_rectangle_I16(bbox: Coords) -> None:
     # Arrange
     im = Image.new("I;16", (W, H))
     draw = ImageDraw.Draw(im)
@@ -754,7 +757,7 @@ def test_rectangle_I16(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_rectangle_translucent_outline(bbox) -> None:
+def test_rectangle_translucent_outline(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im, "RGBA")
@@ -772,7 +775,13 @@ def test_rectangle_translucent_outline(bbox) -> None:
     "xy",
     [(10, 20, 190, 180), ([10, 20], [190, 180]), ((10, 20), (190, 180))],
 )
-def test_rounded_rectangle(xy) -> None:
+def test_rounded_rectangle(
+    xy: (
+        tuple[int, int, int, int]
+        | tuple[list[int]]
+        | tuple[tuple[int, int], tuple[int, int]]
+    )
+) -> None:
     # Arrange
     im = Image.new("RGB", (200, 200))
     draw = ImageDraw.Draw(im)
@@ -789,7 +798,7 @@ def test_rounded_rectangle(xy) -> None:
 @pytest.mark.parametrize("bottom_right", (True, False))
 @pytest.mark.parametrize("bottom_left", (True, False))
 def test_rounded_rectangle_corners(
-    top_left, top_right, bottom_right, bottom_left
+    top_left: bool, top_right: bool, bottom_right: bool, bottom_left: bool
 ) -> None:
     corners = (top_left, top_right, bottom_right, bottom_left)
 
@@ -824,7 +833,9 @@ def test_rounded_rectangle_corners(
         ((10, 20, 190, 181), 85, "height"),
     ],
 )
-def test_rounded_rectangle_non_integer_radius(xy, radius, type) -> None:
+def test_rounded_rectangle_non_integer_radius(
+    xy: tuple[int, int, int, int], radius: float, type: str
+) -> None:
     # Arrange
     im = Image.new("RGB", (200, 200))
     draw = ImageDraw.Draw(im)
@@ -840,7 +851,7 @@ def test_rounded_rectangle_non_integer_radius(xy, radius, type) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_rounded_rectangle_zero_radius(bbox) -> None:
+def test_rounded_rectangle_zero_radius(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -862,7 +873,9 @@ def test_rounded_rectangle_zero_radius(bbox) -> None:
         ((20, 20, 80, 80), "both"),
     ],
 )
-def test_rounded_rectangle_translucent(xy, suffix) -> None:
+def test_rounded_rectangle_translucent(
+    xy: tuple[int, int, int, int], suffix: str
+) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im, "RGBA")
@@ -879,7 +892,7 @@ def test_rounded_rectangle_translucent(xy, suffix) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_floodfill(bbox) -> None:
+def test_floodfill(bbox: Coords) -> None:
     red = ImageColor.getrgb("red")
 
     for mode, value in [("L", 1), ("RGBA", (255, 0, 0, 0)), ("RGB", red)]:
@@ -912,7 +925,7 @@ def test_floodfill(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_floodfill_border(bbox) -> None:
+def test_floodfill_border(bbox: Coords) -> None:
     # floodfill() is experimental
 
     # Arrange
@@ -934,7 +947,7 @@ def test_floodfill_border(bbox) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_floodfill_thresh(bbox) -> None:
+def test_floodfill_thresh(bbox: Coords) -> None:
     # floodfill() is experimental
 
     # Arrange
@@ -968,8 +981,11 @@ def test_floodfill_not_negative() -> None:
 
 
 def create_base_image_draw(
-    size, mode=DEFAULT_MODE, background1=WHITE, background2=GRAY
+    size: tuple[int, int],
-):
+    mode: str = DEFAULT_MODE,
+    background1: tuple[int, int, int] = WHITE,
+    background2: tuple[int, int, int] = GRAY,
+) -> tuple[Image.Image, ImageDraw.ImageDraw]:
     img = Image.new(mode, size, background1)
     for x in range(0, size[0]):
         for y in range(0, size[1]):
@@ -1003,7 +1019,7 @@ def test_triangle_right() -> None:
     "fill, suffix",
     ((BLACK, "width"), (None, "width_no_fill")),
 )
-def test_triangle_right_width(fill, suffix) -> None:
+def test_triangle_right_width(fill: tuple[int, int, int] | None, suffix: str) -> None:
     img, draw = create_base_image_draw((100, 100))
     draw.polygon([(15, 25), (85, 25), (50, 60)], fill, WHITE, width=5)
     assert_image_equal_tofile(
@@ -1235,7 +1251,7 @@ def test_wide_line_larger_than_int() -> None:
         ],
     ],
 )
-def test_line_joint(xy) -> None:
+def test_line_joint(xy: list[tuple[int, int]] | tuple[int, ...] | list[int]) -> None:
     im = Image.new("RGB", (500, 325))
     draw = ImageDraw.Draw(im)
 
@@ -1388,7 +1404,7 @@ def test_default_font_size() -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_same_color_outline(bbox) -> None:
+def test_same_color_outline(bbox: Coords) -> None:
     # Prepare shape
     x0, y0 = 5, 5
     x1, y1 = 5, 50
@@ -1402,7 +1418,8 @@ def test_same_color_outline(bbox) -> None:
 
     # Begin
     for mode in ["RGB", "L"]:
-        for fill, outline in [["red", None], ["red", "red"], ["red", "#f00"]]:
+        fill = "red"
+        for outline in [None, "red", "#f00"]:
             for operation, args in {
                 "chord": [bbox, 0, 180],
                 "ellipse": [bbox],
@@ -1417,6 +1434,7 @@ def test_same_color_outline(bbox) -> None:
 
                 # Act
                 draw_method = getattr(draw, operation)
+                assert isinstance(args, list)
                 args += [fill, outline]
                 draw_method(*args)
 
@@ -1434,7 +1452,9 @@ def test_same_color_outline(bbox) -> None:
         (3, "triangle_width", {"width": 5, "outline": "yellow"}),
     ],
 )
-def test_draw_regular_polygon(n_sides, polygon_name, args) -> None:
+def test_draw_regular_polygon(
+    n_sides: int, polygon_name: str, args: dict[str, int | str]
+) -> None:
     im = Image.new("RGBA", size=(W, H), color=(255, 0, 0, 0))
     filename = f"Tests/images/imagedraw_{polygon_name}.png"
     draw = ImageDraw.Draw(im)
@@ -1471,7 +1491,9 @@ def test_draw_regular_polygon(n_sides, polygon_name, args) -> None:
         ),
     ],
 )
-def test_compute_regular_polygon_vertices(n_sides, expected_vertices) -> None:
+def test_compute_regular_polygon_vertices(
+    n_sides: int, expected_vertices: list[tuple[float, float]]
+) -> None:
     bounding_circle = (W // 2, H // 2, 25)
     vertices = ImageDraw._compute_regular_polygon_vertices(bounding_circle, n_sides, 0)
     assert vertices == expected_vertices
@@ -1482,7 +1504,7 @@ def test_compute_regular_polygon_vertices(n_sides, expected_vertices) -> None:
     [
         (None, (50, 50, 25), 0, TypeError, "n_sides should be an int"),
         (1, (50, 50, 25), 0, ValueError, "n_sides should be an int > 2"),
-        (3, 50, 0, TypeError, "bounding_circle should be a tuple"),
+        (3, 50, 0, TypeError, "bounding_circle should be a sequence"),
         (
             3,
             (50, 50, 100, 100),
@@ -1569,7 +1591,7 @@ def test_polygon2() -> None:
 
 
 @pytest.mark.parametrize("xy", ((1, 1, 0, 1), (1, 1, 1, 0)))
-def test_incorrectly_ordered_coordinates(xy) -> None:
+def test_incorrectly_ordered_coordinates(xy: tuple[int, int, int, int]) -> None:
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
     with pytest.raises(ValueError):

Tests/test_imagemath.py

@@ -5,12 +5,12 @@ import pytest
 from PIL import Image, ImageMath
 
 
-def pixel(im):
+def pixel(im: Image.Image | int) -> str | int:
-    if hasattr(im, "im"):
-        return f"{im.mode} {repr(im.getpixel((0, 0)))}"
     if isinstance(im, int):
         return int(im)  # hack to deal with booleans
 
+    return f"{im.mode} {repr(im.getpixel((0, 0)))}"
+
 
 A = Image.new("L", (1, 1), 1)
 B = Image.new("L", (1, 1), 2)
@@ -60,7 +60,7 @@ def test_ops() -> None:
         "(lambda: (lambda: exec('pass'))())()",
     ),
 )
-def test_prevent_exec(expression) -> None:
+def test_prevent_exec(expression: str) -> None:
     with pytest.raises(ValueError):
         ImageMath.eval(expression)
 

Tests/test_imagetk.py

@@ -57,7 +57,7 @@ def test_kw() -> None:
 
 
 @pytest.mark.parametrize("mode", TK_MODES)
-def test_photoimage(mode) -> None:
+def test_photoimage(mode: str) -> None:
     # test as image:
     im = hopper(mode)
 
@@ -79,7 +79,7 @@ def test_photoimage_apply_transparency() -> None:
 
 
 @pytest.mark.parametrize("mode", TK_MODES)
-def test_photoimage_blank(mode) -> None:
+def test_photoimage_blank(mode: str) -> None:
     # test a image using mode/size:
     im_tk = ImageTk.PhotoImage(mode, (100, 100))
 

Tests/test_lib_pack.py

@@ -10,7 +10,13 @@ X = 255
 
 
 class TestLibPack:
-    def assert_pack(self, mode, rawmode, data, *pixels) -> None:
+    def assert_pack(
+        self,
+        mode: str,
+        rawmode: str,
+        data: int | bytes,
+        *pixels: int | float | tuple[int, ...],
+    ) -> None:
         """
         data - either raw bytes with data or just number of bytes in rawmode.
         """
@@ -228,7 +234,13 @@ class TestLibPack:
 
 
 class TestLibUnpack:
-    def assert_unpack(self, mode, rawmode, data, *pixels) -> None:
+    def assert_unpack(
+        self,
+        mode: str,
+        rawmode: str,
+        data: int | bytes,
+        *pixels: int | float | tuple[int, ...],
+    ) -> None:
         """
         data - either raw bytes with data or just number of bytes in rawmode.
         """

Tests/test_mode_i16.py

@@ -11,7 +11,7 @@ from .helper import hopper
 original = hopper().resize((32, 32)).convert("I")
 
 
-def verify(im1) -> None:
+def verify(im1: Image.Image) -> None:
     im2 = original.copy()
     assert im1.size == im2.size
     pix1 = im1.load()
@@ -27,7 +27,7 @@ def verify(im1) -> None:
 
 
 @pytest.mark.parametrize("mode", ("L", "I;16", "I;16B", "I;16L", "I"))
-def test_basic(tmp_path: Path, mode) -> None:
+def test_basic(tmp_path: Path, mode: str) -> None:
     # PIL 1.1 has limited support for 16-bit image data.  Check that
     # create/copy/transform and save works as expected.
 
@@ -78,7 +78,7 @@ def test_basic(tmp_path: Path, mode) -> None:
 
 
 def test_tobytes() -> None:
-    def tobytes(mode):
+    def tobytes(mode: str) -> Image.Image:
         return Image.new(mode, (1, 1), 1).tobytes()
 
     order = 1 if Image._ENDIAN == "<" else -1

Tests/test_util.py

@@ -1,29 +1,16 @@
 from __future__ import annotations
 
-from pathlib import Path
+from pathlib import Path, PurePath
 
 import pytest
 
 from PIL import _util
 
 
-def test_is_path() -> None:
+@pytest.mark.parametrize(
-    # Arrange
+    "test_path", ["filename.ext", Path("filename.ext"), PurePath("filename.ext")]
-    fp = "filename.ext"
+)
-
+def test_is_path(test_path) -> None:
-    # Act
-    it_is = _util.is_path(fp)
-
-    # Assert
-    assert it_is
-
-
-def test_path_obj_is_path() -> None:
-    # Arrange
-    from pathlib import Path
-
-    test_path = Path("filename.ext")
-
     # Act
     it_is = _util.is_path(test_path)
 

docs/reference/internal_design.rst

@@ -1,5 +1,5 @@
-Internal Reference Docs
+Internal Reference
-=======================
+==================
 
 .. toctree::
   :maxdepth: 2

docs/reference/internal_modules.rst

@@ -33,6 +33,14 @@ Internal Modules
 Provides a convenient way to import type hints that are not available
 on some Python versions.
 
+.. py:class:: StrOrBytesPath
+
+    Typing alias.
+
+.. py:class:: SupportsRead
+
+    An object that supports the read method.
+
 .. py:data:: TypeGuard
     :value: typing.TypeGuard
 

docs/reference/open_files.rst

@@ -3,7 +3,7 @@
 File Handling in Pillow
 =======================
 
-When opening a file as an image, Pillow requires a filename, ``pathlib.Path``
+When opening a file as an image, Pillow requires a filename, ``os.PathLike``
 object, or a file-like object. Pillow uses the filename or ``Path`` to open a
 file, so for the rest of this article, they will all be treated as a file-like
 object.

pyproject.toml

@@ -141,16 +141,6 @@ warn_redundant_casts = true
 warn_unreachable = true
 warn_unused_ignores = true
 exclude = [
-  '^src/PIL/_tkinter_finder.py$',
-  '^src/PIL/DdsImagePlugin.py$',
   '^src/PIL/FpxImagePlugin.py$',
-  '^src/PIL/Image.py$',
-  '^src/PIL/ImageQt.py$',
-  '^src/PIL/ImImagePlugin.py$',
   '^src/PIL/MicImagePlugin.py$',
-  '^src/PIL/PdfParser.py$',
-  '^src/PIL/PyAccess.py$',
-  '^src/PIL/TiffImagePlugin.py$',
-  '^src/PIL/TiffTags.py$',
-  '^src/PIL/WebPImagePlugin.py$',
 ]

src/PIL/DdsImagePlugin.py

@@ -270,13 +270,17 @@ class D3DFMT(IntEnum):
 # Backward compatibility layer
 module = sys.modules[__name__]
 for item in DDSD:
+    assert item.name is not None
     setattr(module, "DDSD_" + item.name, item.value)
-for item in DDSCAPS:
+for item1 in DDSCAPS:
-    setattr(module, "DDSCAPS_" + item.name, item.value)
+    assert item1.name is not None
-for item in DDSCAPS2:
+    setattr(module, "DDSCAPS_" + item1.name, item1.value)
-    setattr(module, "DDSCAPS2_" + item.name, item.value)
+for item2 in DDSCAPS2:
-for item in DDPF:
+    assert item2.name is not None
-    setattr(module, "DDPF_" + item.name, item.value)
+    setattr(module, "DDSCAPS2_" + item2.name, item2.value)
+for item3 in DDPF:
+    assert item3.name is not None
+    setattr(module, "DDPF_" + item3.name, item3.value)
 
 DDS_FOURCC = DDPF.FOURCC
 DDS_RGB = DDPF.RGB

src/PIL/GdImageFile.py

@@ -27,11 +27,12 @@
 """
 from __future__ import annotations
 
-from io import BytesIO
+from typing import IO
 
 from . import ImageFile, ImagePalette, UnidentifiedImageError
 from ._binary import i16be as i16
 from ._binary import i32be as i32
+from ._typing import StrOrBytesPath
 
 
 class GdImageFile(ImageFile.ImageFile):
@@ -80,7 +81,7 @@ class GdImageFile(ImageFile.ImageFile):
         ]
 
 
-def open(fp: BytesIO, mode: str = "r") -> GdImageFile:
+def open(fp: StrOrBytesPath | IO[bytes], mode: str = "r") -> GdImageFile:
     """
     Load texture from a GD image file.
 

src/PIL/ImImagePlugin.py

@@ -93,8 +93,8 @@ for i in ["16", "16L", "16B"]:
 for i in ["32S"]:
     OPEN[f"L {i} image"] = ("I", f"I;{i}")
     OPEN[f"L*{i} image"] = ("I", f"I;{i}")
-for i in range(2, 33):
+for j in range(2, 33):
-    OPEN[f"L*{i} image"] = ("F", f"F;{i}")
+    OPEN[f"L*{j} image"] = ("F", f"F;{j}")
 
 
 # --------------------------------------------------------------------

src/PIL/Image.py

@@ -26,6 +26,7 @@
 
 from __future__ import annotations
 
+import abc
 import atexit
 import builtins
 import io
@@ -39,12 +40,8 @@ import tempfile
 import warnings
 from collections.abc import Callable, MutableMapping
 from enum import IntEnum
-from pathlib import Path
+from types import ModuleType
-
+from typing import IO, TYPE_CHECKING, Any
-try:
-    from defusedxml import ElementTree
-except ImportError:
-    ElementTree = None
 
 # VERSION was removed in Pillow 6.0.0.
 # PILLOW_VERSION was removed in Pillow 9.0.0.
@@ -60,6 +57,12 @@ from . import (
 from ._binary import i32le, o32be, o32le
 from ._util import DeferredError, is_path
 
+ElementTree: ModuleType | None
+try:
+    from defusedxml import ElementTree
+except ImportError:
+    ElementTree = None
+
 logger = logging.getLogger(__name__)
 
 
@@ -110,6 +113,7 @@ except ImportError as v:
 
 
 USE_CFFI_ACCESS = False
+cffi: ModuleType | None
 try:
     import cffi
 except ImportError:
@@ -211,14 +215,22 @@ if hasattr(core, "DEFAULT_STRATEGY"):
 # --------------------------------------------------------------------
 # Registries
 
-ID = []
+if TYPE_CHECKING:
-OPEN = {}
+    from . import ImageFile
-MIME = {}
+ID: list[str] = []
-SAVE = {}
+OPEN: dict[
-SAVE_ALL = {}
+    str,
-EXTENSION = {}
+    tuple[
-DECODERS = {}
+        Callable[[IO[bytes], str | bytes], ImageFile.ImageFile],
-ENCODERS = {}
+        Callable[[bytes], bool] | None,
+    ],
+] = {}
+MIME: dict[str, str] = {}
+SAVE: dict[str, Callable[[Image, IO[bytes], str | bytes], None]] = {}
+SAVE_ALL: dict[str, Callable[[Image, IO[bytes], str | bytes], None]] = {}
+EXTENSION: dict[str, str] = {}
+DECODERS: dict[str, object] = {}
+ENCODERS: dict[str, object] = {}
 
 # --------------------------------------------------------------------
 # Modes
@@ -571,7 +583,7 @@ class Image:
         # object is gone.
         self.im = DeferredError(ValueError("Operation on closed image"))
 
-    def _copy(self):
+    def _copy(self) -> None:
         self.load()
         self.im = self.im.copy()
         self.pyaccess = None
@@ -2370,7 +2382,7 @@ class Image:
         implement the ``seek``, ``tell``, and ``write``
         methods, and be opened in binary mode.
 
-        :param fp: A filename (string), pathlib.Path object or file object.
+        :param fp: A filename (string), os.PathLike object or file object.
         :param format: Optional format override.  If omitted, the
            format to use is determined from the filename extension.
            If a file object was used instead of a filename, this
@@ -2383,13 +2395,10 @@ class Image:
            may have been created, and may contain partial data.
         """
 
-        filename = ""
+        filename: str | bytes = ""
         open_fp = False
-        if isinstance(fp, Path):
+        if is_path(fp):
-            filename = str(fp)
+            filename = os.path.realpath(os.fspath(fp))
-            open_fp = True
-        elif is_path(fp):
-            filename = fp
             open_fp = True
         elif fp == sys.stdout:
             try:
@@ -2398,7 +2407,7 @@ class Image:
                 pass
         if not filename and hasattr(fp, "name") and is_path(fp.name):
             # only set the name for metadata purposes
-            filename = fp.name
+            filename = os.path.realpath(os.fspath(fp.name))
 
         # may mutate self!
         self._ensure_mutable()
@@ -2409,7 +2418,8 @@ class Image:
 
         preinit()
 
-        ext = os.path.splitext(filename)[1].lower()
+        filename_ext = os.path.splitext(filename)[1].lower()
+        ext = filename_ext.decode() if isinstance(filename_ext, bytes) else filename_ext
 
         if not format:
             if ext not in EXTENSION:
@@ -2451,7 +2461,7 @@ class Image:
         if open_fp:
             fp.close()
 
-    def seek(self, frame) -> Image:
+    def seek(self, frame) -> None:
         """
         Seeks to the given frame in this sequence file. If you seek
         beyond the end of the sequence, the method raises an
@@ -2511,10 +2521,8 @@ class Image:
 
         self.load()
         if self.im.bands == 1:
-            ims = [self.copy()]
+            return (self.copy(),)
-        else:
+        return tuple(map(self._new, self.im.split()))
-            ims = map(self._new, self.im.split())
-        return tuple(ims)
 
     def getchannel(self, channel):
         """
@@ -2871,7 +2879,14 @@ class ImageTransformHandler:
     (for use with :py:meth:`~PIL.Image.Image.transform`)
     """
 
-    pass
+    @abc.abstractmethod
+    def transform(
+        self,
+        size: tuple[int, int],
+        image: Image,
+        **options: dict[str, str | int | tuple[int, ...] | list[int]],
+    ) -> Image:
+        pass
 
 
 # --------------------------------------------------------------------
@@ -3206,7 +3221,7 @@ def open(fp, mode="r", formats=None) -> Image:
     :py:meth:`~PIL.Image.Image.load` method).  See
     :py:func:`~PIL.Image.new`. See :ref:`file-handling`.
 
-    :param fp: A filename (string), pathlib.Path object or a file object.
+    :param fp: A filename (string), os.PathLike object or a file object.
        The file object must implement ``file.read``,
        ``file.seek``, and ``file.tell`` methods,
        and be opened in binary mode. The file object will also seek to zero
@@ -3243,11 +3258,9 @@ def open(fp, mode="r", formats=None) -> Image:
         raise TypeError(msg)
 
     exclusive_fp = False
-    filename = ""
+    filename: str | bytes = ""
-    if isinstance(fp, Path):
+    if is_path(fp):
-        filename = str(fp.resolve())
+        filename = os.path.realpath(os.fspath(fp))
-    elif is_path(fp):
-        filename = fp
 
     if filename:
         fp = builtins.open(filename, "rb")
@@ -3421,7 +3434,11 @@ def merge(mode, bands):
 # Plugin registry
 
 
-def register_open(id, factory, accept=None) -> None:
+def register_open(
+    id,
+    factory: Callable[[IO[bytes], str | bytes], ImageFile.ImageFile],
+    accept: Callable[[bytes], bool] | None = None,
+) -> None:
     """
     Register an image file plugin.  This function should not be used
     in application code.
@@ -3631,7 +3648,13 @@ _apply_env_variables()
 atexit.register(core.clear_cache)
 
 
-class Exif(MutableMapping):
+if TYPE_CHECKING:
+    _ExifBase = MutableMapping[int, Any]
+else:
+    _ExifBase = MutableMapping
+
+
+class Exif(_ExifBase):
     """
     This class provides read and write access to EXIF image data::
 

src/PIL/ImageDraw.py

@@ -34,8 +34,10 @@ from __future__ import annotations
 import math
 import numbers
 import struct
+from typing import Sequence, cast
 
 from . import Image, ImageColor
+from ._typing import Coords
 
 """
 A simple 2D drawing interface for PIL images.
@@ -48,7 +50,7 @@ directly.
 class ImageDraw:
     font = None
 
-    def __init__(self, im, mode=None):
+    def __init__(self, im: Image.Image, mode: str | None = None) -> None:
         """
         Create a drawing instance.
 
@@ -115,7 +117,7 @@ class ImageDraw:
             self.font = ImageFont.load_default()
         return self.font
 
-    def _getfont(self, font_size):
+    def _getfont(self, font_size: float | None):
         if font_size is not None:
             from . import ImageFont
 
@@ -124,7 +126,7 @@ class ImageDraw:
             font = self.getfont()
         return font
 
-    def _getink(self, ink, fill=None):
+    def _getink(self, ink, fill=None) -> tuple[int | None, int | None]:
         if ink is None and fill is None:
             if self.fill:
                 fill = self.ink
@@ -145,13 +147,13 @@ class ImageDraw:
                 fill = self.draw.draw_ink(fill)
         return ink, fill
 
-    def arc(self, xy, start, end, fill=None, width=1):
+    def arc(self, xy: Coords, start, end, fill=None, width=1) -> None:
         """Draw an arc."""
         ink, fill = self._getink(fill)
         if ink is not None:
             self.draw.draw_arc(xy, start, end, ink, width)
 
-    def bitmap(self, xy, bitmap, fill=None):
+    def bitmap(self, xy: Sequence[int], bitmap, fill=None) -> None:
         """Draw a bitmap."""
         bitmap.load()
         ink, fill = self._getink(fill)
@@ -160,7 +162,7 @@ class ImageDraw:
         if ink is not None:
             self.draw.draw_bitmap(xy, bitmap.im, ink)
 
-    def chord(self, xy, start, end, fill=None, outline=None, width=1):
+    def chord(self, xy: Coords, start, end, fill=None, outline=None, width=1) -> None:
         """Draw a chord."""
         ink, fill = self._getink(outline, fill)
         if fill is not None:
@@ -168,7 +170,7 @@ class ImageDraw:
         if ink is not None and ink != fill and width != 0:
             self.draw.draw_chord(xy, start, end, ink, 0, width)
 
-    def ellipse(self, xy, fill=None, outline=None, width=1):
+    def ellipse(self, xy: Coords, fill=None, outline=None, width=1) -> None:
         """Draw an ellipse."""
         ink, fill = self._getink(outline, fill)
         if fill is not None:
@@ -176,20 +178,29 @@ class ImageDraw:
         if ink is not None and ink != fill and width != 0:
             self.draw.draw_ellipse(xy, ink, 0, width)
 
-    def line(self, xy, fill=None, width=0, joint=None):
+    def line(self, xy: Coords, fill=None, width=0, joint=None) -> None:
         """Draw a line, or a connected sequence of line segments."""
         ink = self._getink(fill)[0]
         if ink is not None:
             self.draw.draw_lines(xy, ink, width)
             if joint == "curve" and width > 4:
-                if not isinstance(xy[0], (list, tuple)):
+                points: Sequence[Sequence[float]]
-                    xy = [tuple(xy[i : i + 2]) for i in range(0, len(xy), 2)]
+                if isinstance(xy[0], (list, tuple)):
-                for i in range(1, len(xy) - 1):
+                    points = cast(Sequence[Sequence[float]], xy)
-                    point = xy[i]
+                else:
+                    points = [
+                        cast(Sequence[float], tuple(xy[i : i + 2]))
+                        for i in range(0, len(xy), 2)
+                    ]
+                for i in range(1, len(points) - 1):
+                    point = points[i]
                     angles = [
                         math.degrees(math.atan2(end[0] - start[0], start[1] - end[1]))
                         % 360
-                        for start, end in ((xy[i - 1], point), (point, xy[i + 1]))
+                        for start, end in (
+                            (points[i - 1], point),
+                            (point, points[i + 1]),
+                        )
                     ]
                     if angles[0] == angles[1]:
                         # This is a straight line, so no joint is required
@@ -236,7 +247,7 @@ class ImageDraw:
                             ]
                         self.line(gap_coords, fill, width=3)
 
-    def shape(self, shape, fill=None, outline=None):
+    def shape(self, shape, fill=None, outline=None) -> None:
         """(Experimental) Draw a shape."""
         shape.close()
         ink, fill = self._getink(outline, fill)
@@ -245,7 +256,9 @@ class ImageDraw:
         if ink is not None and ink != fill:
             self.draw.draw_outline(shape, ink, 0)
 
-    def pieslice(self, xy, start, end, fill=None, outline=None, width=1):
+    def pieslice(
+        self, xy: Coords, start, end, fill=None, outline=None, width=1
+    ) -> None:
         """Draw a pieslice."""
         ink, fill = self._getink(outline, fill)
         if fill is not None:
@@ -253,13 +266,13 @@ class ImageDraw:
         if ink is not None and ink != fill and width != 0:
             self.draw.draw_pieslice(xy, start, end, ink, 0, width)
 
-    def point(self, xy, fill=None):
+    def point(self, xy: Coords, fill=None) -> None:
         """Draw one or more individual pixels."""
         ink, fill = self._getink(fill)
         if ink is not None:
             self.draw.draw_points(xy, ink)
 
-    def polygon(self, xy, fill=None, outline=None, width=1):
+    def polygon(self, xy: Coords, fill=None, outline=None, width=1) -> None:
         """Draw a polygon."""
         ink, fill = self._getink(outline, fill)
         if fill is not None:
@@ -267,7 +280,7 @@ class ImageDraw:
         if ink is not None and ink != fill and width != 0:
             if width == 1:
                 self.draw.draw_polygon(xy, ink, 0, width)
-            else:
+            elif self.im is not None:
                 # To avoid expanding the polygon outwards,
                 # use the fill as a mask
                 mask = Image.new("1", self.im.size)
@@ -291,12 +304,12 @@ class ImageDraw:
 
     def regular_polygon(
         self, bounding_circle, n_sides, rotation=0, fill=None, outline=None, width=1
-    ):
+    ) -> None:
         """Draw a regular polygon."""
         xy = _compute_regular_polygon_vertices(bounding_circle, n_sides, rotation)
         self.polygon(xy, fill, outline, width)
 
-    def rectangle(self, xy, fill=None, outline=None, width=1):
+    def rectangle(self, xy: Coords, fill=None, outline=None, width=1) -> None:
         """Draw a rectangle."""
         ink, fill = self._getink(outline, fill)
         if fill is not None:
@@ -305,13 +318,13 @@ class ImageDraw:
             self.draw.draw_rectangle(xy, ink, 0, width)
 
     def rounded_rectangle(
-        self, xy, radius=0, fill=None, outline=None, width=1, *, corners=None
+        self, xy: Coords, radius=0, fill=None, outline=None, width=1, *, corners=None
-    ):
+    ) -> None:
         """Draw a rounded rectangle."""
         if isinstance(xy[0], (list, tuple)):
-            (x0, y0), (x1, y1) = xy
+            (x0, y0), (x1, y1) = cast(Sequence[Sequence[float]], xy)
         else:
-            x0, y0, x1, y1 = xy
+            x0, y0, x1, y1 = cast(Sequence[float], xy)
         if x1 < x0:
             msg = "x1 must be greater than or equal to x0"
             raise ValueError(msg)
@@ -346,7 +359,8 @@ class ImageDraw:
         r = d // 2
         ink, fill = self._getink(outline, fill)
 
-        def draw_corners(pieslice):
+        def draw_corners(pieslice) -> None:
+            parts: tuple[tuple[tuple[float, float, float, float], int, int], ...]
             if full_x:
                 # Draw top and bottom halves
                 parts = (
@@ -361,17 +375,18 @@ class ImageDraw:
                 )
             else:
                 # Draw four separate corners
-                parts = []
+                parts = tuple(
-                for i, part in enumerate(
+                    part
-                    (
+                    for i, part in enumerate(
-                        ((x0, y0, x0 + d, y0 + d), 180, 270),
+                        (
-                        ((x1 - d, y0, x1, y0 + d), 270, 360),
+                            ((x0, y0, x0 + d, y0 + d), 180, 270),
-                        ((x1 - d, y1 - d, x1, y1), 0, 90),
+                            ((x1 - d, y0, x1, y0 + d), 270, 360),
-                        ((x0, y1 - d, x0 + d, y1), 90, 180),
+                            ((x1 - d, y1 - d, x1, y1), 0, 90),
+                            ((x0, y1 - d, x0 + d, y1), 90, 180),
+                        )
                     )
-                ):
+                    if corners[i]
-                    if corners[i]:
+                )
-                        parts.append(part)
             for part in parts:
                 if pieslice:
                     self.draw.draw_pieslice(*(part + (fill, 1)))
@@ -431,12 +446,12 @@ class ImageDraw:
                     right[3] -= r + 1
                 self.draw.draw_rectangle(right, ink, 1)
 
-    def _multiline_check(self, text):
+    def _multiline_check(self, text) -> bool:
         split_character = "\n" if isinstance(text, str) else b"\n"
 
         return split_character in text
 
-    def _multiline_split(self, text):
+    def _multiline_split(self, text) -> list[str | bytes]:
         split_character = "\n" if isinstance(text, str) else b"\n"
 
         return text.split(split_character)
@@ -465,7 +480,7 @@ class ImageDraw:
         embedded_color=False,
         *args,
         **kwargs,
-    ):
+    ) -> None:
         """Draw text."""
         if embedded_color and self.mode not in ("RGB", "RGBA"):
             msg = "Embedded color supported only in RGB and RGBA modes"
@@ -497,7 +512,7 @@ class ImageDraw:
                 return fill
             return ink
 
-        def draw_text(ink, stroke_width=0, stroke_offset=None):
+        def draw_text(ink, stroke_width=0, stroke_offset=None) -> None:
             mode = self.fontmode
             if stroke_width == 0 and embedded_color:
                 mode = "RGBA"
@@ -520,7 +535,7 @@ class ImageDraw:
                     *args,
                     **kwargs,
                 )
-                coord = coord[0] + offset[0], coord[1] + offset[1]
+                coord = [coord[0] + offset[0], coord[1] + offset[1]]
             except AttributeError:
                 try:
                     mask = font.getmask(
@@ -539,7 +554,7 @@ class ImageDraw:
                 except TypeError:
                     mask = font.getmask(text)
             if stroke_offset:
-                coord = coord[0] + stroke_offset[0], coord[1] + stroke_offset[1]
+                coord = [coord[0] + stroke_offset[0], coord[1] + stroke_offset[1]]
             if mode == "RGBA":
                 # font.getmask2(mode="RGBA") returns color in RGB bands and mask in A
                 # extract mask and set text alpha
@@ -547,7 +562,10 @@ class ImageDraw:
                 ink_alpha = struct.pack("i", ink)[3]
                 color.fillband(3, ink_alpha)
                 x, y = coord
-                self.im.paste(color, (x, y, x + mask.size[0], y + mask.size[1]), mask)
+                if self.im is not None:
+                    self.im.paste(
+                        color, (x, y, x + mask.size[0], y + mask.size[1]), mask
+                    )
             else:
                 self.draw.draw_bitmap(coord, mask, ink)
 
@@ -584,7 +602,7 @@ class ImageDraw:
         embedded_color=False,
         *,
         font_size=None,
-    ):
+    ) -> None:
         if direction == "ttb":
             msg = "ttb direction is unsupported for multiline text"
             raise ValueError(msg)
@@ -693,7 +711,7 @@ class ImageDraw:
         embedded_color=False,
         *,
         font_size=None,
-    ):
+    ) -> tuple[int, int, int, int]:
         """Get the bounding box of a given string, in pixels."""
         if embedded_color and self.mode not in ("RGB", "RGBA"):
             msg = "Embedded color supported only in RGB and RGBA modes"
@@ -738,7 +756,7 @@ class ImageDraw:
         embedded_color=False,
         *,
         font_size=None,
-    ):
+    ) -> tuple[int, int, int, int]:
         if direction == "ttb":
             msg = "ttb direction is unsupported for multiline text"
             raise ValueError(msg)
@@ -777,7 +795,7 @@ class ImageDraw:
         elif anchor[1] == "d":
             top -= (len(lines) - 1) * line_spacing
 
-        bbox = None
+        bbox: tuple[int, int, int, int] | None = None
 
         for idx, line in enumerate(lines):
             left = xy[0]
@@ -828,7 +846,7 @@ class ImageDraw:
         return bbox
 
 
-def Draw(im, mode=None):
+def Draw(im, mode: str | None = None) -> ImageDraw:
     """
     A simple 2D drawing interface for PIL images.
 
@@ -876,7 +894,7 @@ def getdraw(im=None, hints=None):
     return im, handler
 
 
-def floodfill(image, xy, value, border=None, thresh=0):
+def floodfill(image: Image.Image, xy, value, border=None, thresh=0) -> None:
     """
     (experimental) Fills a bounded region with a given color.
 
@@ -932,7 +950,9 @@ def floodfill(image, xy, value, border=None, thresh=0):
         edge = new_edge
 
 
-def _compute_regular_polygon_vertices(bounding_circle, n_sides, rotation):
+def _compute_regular_polygon_vertices(
+    bounding_circle, n_sides, rotation
+) -> list[tuple[float, float]]:
     """
     Generate a list of vertices for a 2D regular polygon.
 
@@ -982,7 +1002,7 @@ def _compute_regular_polygon_vertices(bounding_circle, n_sides, rotation):
 
     # 1.2 Check `bounding_circle` has an appropriate value
     if not isinstance(bounding_circle, (list, tuple)):
-        msg = "bounding_circle should be a tuple"
+        msg = "bounding_circle should be a sequence"
         raise TypeError(msg)
 
     if len(bounding_circle) == 3:
@@ -1014,7 +1034,7 @@ def _compute_regular_polygon_vertices(bounding_circle, n_sides, rotation):
         raise ValueError(msg)
 
     # 2. Define Helper Functions
-    def _apply_rotation(point, degrees, centroid):
+    def _apply_rotation(point: list[float], degrees: float) -> tuple[int, int]:
         return (
             round(
                 point[0] * math.cos(math.radians(360 - degrees))
@@ -1030,11 +1050,11 @@ def _compute_regular_polygon_vertices(bounding_circle, n_sides, rotation):
             ),
         )
 
-    def _compute_polygon_vertex(centroid, polygon_radius, angle):
+    def _compute_polygon_vertex(angle: float) -> tuple[int, int]:
         start_point = [polygon_radius, 0]
-        return _apply_rotation(start_point, angle, centroid)
+        return _apply_rotation(start_point, angle)
 
-    def _get_angles(n_sides, rotation):
+    def _get_angles(n_sides: int, rotation: float) -> list[float]:
         angles = []
         degrees = 360 / n_sides
         # Start with the bottom left polygon vertex
@@ -1050,12 +1070,10 @@ def _compute_regular_polygon_vertices(bounding_circle, n_sides, rotation):
     angles = _get_angles(n_sides, rotation)
 
     # 4. Compute Vertices
-    return [
+    return [_compute_polygon_vertex(angle) for angle in angles]
-        _compute_polygon_vertex(centroid, polygon_radius, angle) for angle in angles
-    ]
 
 
-def _color_diff(color1, color2):
+def _color_diff(color1, color2: float | tuple[int, ...]) -> float:
     """
     Uses 1-norm distance to calculate difference between two values.
     """

src/PIL/ImageFont.py

@@ -33,10 +33,10 @@ import sys
 import warnings
 from enum import IntEnum
 from io import BytesIO
-from pathlib import Path
 from typing import BinaryIO
 
 from . import Image
+from ._typing import StrOrBytesPath
 from ._util import is_directory, is_path
 
 
@@ -193,7 +193,7 @@ class FreeTypeFont:
 
     def __init__(
         self,
-        font: bytes | str | Path | BinaryIO | None = None,
+        font: StrOrBytesPath | BinaryIO | None = None,
         size: float = 10,
         index: int = 0,
         encoding: str = "",
@@ -230,8 +230,7 @@ class FreeTypeFont:
             )
 
         if is_path(font):
-            if isinstance(font, Path):
+            font = os.path.realpath(os.fspath(font))
-                font = str(font)
             if sys.platform == "win32":
                 font_bytes_path = font if isinstance(font, bytes) else font.encode()
                 try:
@@ -872,7 +871,7 @@ def load_path(filename):
     raise OSError(msg)
 
 
-def load_default(size=None):
+def load_default(size: float | None = None) -> FreeTypeFont | ImageFont:
     """If FreeType support is available, load a version of Aileron Regular,
     https://dotcolon.net/font/aileron, with a more limited character set.
 

src/PIL/ImageQt.py

@@ -19,19 +19,26 @@ from __future__ import annotations
 
 import sys
 from io import BytesIO
+from typing import Callable
 
 from . import Image
 from ._util import is_path
 
+qt_version: str | None
 qt_versions = [
     ["6", "PyQt6"],
     ["side6", "PySide6"],
 ]
 
 # If a version has already been imported, attempt it first
-qt_versions.sort(key=lambda qt_version: qt_version[1] in sys.modules, reverse=True)
+qt_versions.sort(key=lambda version: version[1] in sys.modules, reverse=True)
-for qt_version, qt_module in qt_versions:
+for version, qt_module in qt_versions:
     try:
+        QBuffer: type
+        QIODevice: type
+        QImage: type
+        QPixmap: type
+        qRgba: Callable[[int, int, int, int], int]
         if qt_module == "PyQt6":
             from PyQt6.QtCore import QBuffer, QIODevice
             from PyQt6.QtGui import QImage, QPixmap, qRgba
@@ -41,6 +48,7 @@ for qt_version, qt_module in qt_versions:
     except (ImportError, RuntimeError):
         continue
     qt_is_installed = True
+    qt_version = version
     break
 else:
     qt_is_installed = False

src/PIL/ImageShow.py

@@ -184,7 +184,7 @@ class UnixViewer(Viewer):
 
     @abc.abstractmethod
     def get_command_ex(self, file: str, **options: Any) -> tuple[str, str]:
-        pass  # pragma: no cover
+        pass
 
     def get_command(self, file: str, **options: Any) -> str:
         command = self.get_command_ex(file, **options)[0]

src/PIL/MpegImagePlugin.py

@@ -14,17 +14,16 @@
 #
 from __future__ import annotations
 
-from io import BytesIO
-
 from . import Image, ImageFile
 from ._binary import i8
+from ._typing import SupportsRead
 
 #
 # Bitstream parser
 
 
 class BitStream:
-    def __init__(self, fp: BytesIO) -> None:
+    def __init__(self, fp: SupportsRead[bytes]) -> None:
         self.fp = fp
         self.bits = 0
         self.bitbuffer = 0

src/PIL/PdfParser.py

@@ -8,6 +8,7 @@ import os
 import re
 import time
 import zlib
+from typing import TYPE_CHECKING, Any, List, Union
 
 
 # see 7.9.2.2 Text String Type on page 86 and D.3 PDFDocEncoding Character Set
@@ -239,12 +240,18 @@ class PdfName:
         return bytes(result)
 
 
-class PdfArray(list):
+class PdfArray(List[Any]):
     def __bytes__(self):
         return b"[ " + b" ".join(pdf_repr(x) for x in self) + b" ]"
 
 
-class PdfDict(collections.UserDict):
+if TYPE_CHECKING:
+    _DictBase = collections.UserDict[Union[str, bytes], Any]
+else:
+    _DictBase = collections.UserDict
+
+
+class PdfDict(_DictBase):
     def __setattr__(self, key, value):
         if key == "data":
             collections.UserDict.__setattr__(self, key, value)

src/PIL/PyAccess.py

@@ -25,6 +25,7 @@ import sys
 
 from ._deprecate import deprecate
 
+FFI: type
 try:
     from cffi import FFI
 

src/PIL/TiffImagePlugin.py

@@ -50,6 +50,7 @@ import warnings
 from collections.abc import MutableMapping
 from fractions import Fraction
 from numbers import Number, Rational
+from typing import TYPE_CHECKING, Any, Callable
 
 from . import ExifTags, Image, ImageFile, ImageOps, ImagePalette, TiffTags
 from ._binary import i16be as i16
@@ -306,6 +307,13 @@ _load_dispatch = {}
 _write_dispatch = {}
 
 
+def _delegate(op):
+    def delegate(self, *args):
+        return getattr(self._val, op)(*args)
+
+    return delegate
+
+
 class IFDRational(Rational):
     """Implements a rational class where 0/0 is a legal value to match
     the in the wild use of exif rationals.
@@ -391,12 +399,6 @@ class IFDRational(Rational):
         self._numerator = _numerator
         self._denominator = _denominator
 
-    def _delegate(op):
-        def delegate(self, *args):
-            return getattr(self._val, op)(*args)
-
-        return delegate
-
     """ a = ['add','radd', 'sub', 'rsub', 'mul', 'rmul',
              'truediv', 'rtruediv', 'floordiv', 'rfloordiv',
              'mod','rmod', 'pow','rpow', 'pos', 'neg',
@@ -436,7 +438,50 @@ class IFDRational(Rational):
         __int__ = _delegate("__int__")
 
 
-class ImageFileDirectory_v2(MutableMapping):
+def _register_loader(idx, size):
+    def decorator(func):
+        from .TiffTags import TYPES
+
+        if func.__name__.startswith("load_"):
+            TYPES[idx] = func.__name__[5:].replace("_", " ")
+        _load_dispatch[idx] = size, func  # noqa: F821
+        return func
+
+    return decorator
+
+
+def _register_writer(idx):
+    def decorator(func):
+        _write_dispatch[idx] = func  # noqa: F821
+        return func
+
+    return decorator
+
+
+def _register_basic(idx_fmt_name):
+    from .TiffTags import TYPES
+
+    idx, fmt, name = idx_fmt_name
+    TYPES[idx] = name
+    size = struct.calcsize("=" + fmt)
+    _load_dispatch[idx] = (  # noqa: F821
+        size,
+        lambda self, data, legacy_api=True: (
+            self._unpack(f"{len(data) // size}{fmt}", data)
+        ),
+    )
+    _write_dispatch[idx] = lambda self, *values: (  # noqa: F821
+        b"".join(self._pack(fmt, value) for value in values)
+    )
+
+
+if TYPE_CHECKING:
+    _IFDv2Base = MutableMapping[int, Any]
+else:
+    _IFDv2Base = MutableMapping
+
+
+class ImageFileDirectory_v2(_IFDv2Base):
     """This class represents a TIFF tag directory.  To speed things up, we
     don't decode tags unless they're asked for.
 
@@ -497,6 +542,9 @@ class ImageFileDirectory_v2(MutableMapping):
 
     """
 
+    _load_dispatch: dict[int, Callable[[ImageFileDirectory_v2, bytes, bool], Any]] = {}
+    _write_dispatch: dict[int, Callable[..., Any]] = {}
+
     def __init__(self, ifh=b"II\052\0\0\0\0\0", prefix=None, group=None):
         """Initialize an ImageFileDirectory.
 
@@ -531,7 +579,10 @@ class ImageFileDirectory_v2(MutableMapping):
 
     prefix = property(lambda self: self._prefix)
     offset = property(lambda self: self._offset)
-    legacy_api = property(lambda self: self._legacy_api)
+
+    @property
+    def legacy_api(self):
+        return self._legacy_api
 
     @legacy_api.setter
     def legacy_api(self, value):
@@ -674,40 +725,6 @@ class ImageFileDirectory_v2(MutableMapping):
     def _pack(self, fmt, *values):
         return struct.pack(self._endian + fmt, *values)
 
-    def _register_loader(idx, size):
-        def decorator(func):
-            from .TiffTags import TYPES
-
-            if func.__name__.startswith("load_"):
-                TYPES[idx] = func.__name__[5:].replace("_", " ")
-            _load_dispatch[idx] = size, func  # noqa: F821
-            return func
-
-        return decorator
-
-    def _register_writer(idx):
-        def decorator(func):
-            _write_dispatch[idx] = func  # noqa: F821
-            return func
-
-        return decorator
-
-    def _register_basic(idx_fmt_name):
-        from .TiffTags import TYPES
-
-        idx, fmt, name = idx_fmt_name
-        TYPES[idx] = name
-        size = struct.calcsize("=" + fmt)
-        _load_dispatch[idx] = (  # noqa: F821
-            size,
-            lambda self, data, legacy_api=True: (
-                self._unpack(f"{len(data) // size}{fmt}", data)
-            ),
-        )
-        _write_dispatch[idx] = lambda self, *values: (  # noqa: F821
-            b"".join(self._pack(fmt, value) for value in values)
-        )
-
     list(
         map(
             _register_basic,
@@ -995,7 +1012,7 @@ class ImageFileDirectory_v1(ImageFileDirectory_v2):
     tagdata = property(lambda self: self._tagdata)
 
     # defined in ImageFileDirectory_v2
-    tagtype: dict
+    tagtype: dict[int, int]
     """Dictionary of tag types"""
 
     @classmethod
@@ -1835,11 +1852,11 @@ def _save(im, fp, filename):
         tags = list(atts.items())
         tags.sort()
         a = (rawmode, compression, _fp, filename, tags, types)
-        e = Image._getencoder(im.mode, "libtiff", a, encoderconfig)
+        encoder = Image._getencoder(im.mode, "libtiff", a, encoderconfig)
-        e.setimage(im.im, (0, 0) + im.size)
+        encoder.setimage(im.im, (0, 0) + im.size)
         while True:
             # undone, change to self.decodermaxblock:
-            errcode, data = e.encode(16 * 1024)[1:]
+            errcode, data = encoder.encode(16 * 1024)[1:]
             if not _fp:
                 fp.write(data)
             if errcode:

src/PIL/TiffTags.py

@@ -22,7 +22,7 @@ from collections import namedtuple
 
 
 class TagInfo(namedtuple("_TagInfo", "value name type length enum")):
-    __slots__ = []
+    __slots__: list[str] = []
 
     def __new__(cls, value=None, name="unknown", type=None, length=None, enum=None):
         return super().__new__(cls, value, name, type, length, enum or {})
@@ -437,7 +437,7 @@ _populate()
 ##
 # Map type numbers to type names -- defined in ImageFileDirectory.
 
-TYPES = {}
+TYPES: dict[int, str] = {}
 
 #
 # These tags are handled by default in libtiff, without

src/PIL/_imaging.pyi

@@ -0,0 +1,5 @@
+from __future__ import annotations
+
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

src/PIL/_tkinter_finder.py

@@ -5,7 +5,8 @@ from __future__ import annotations
 
 import sys
 import tkinter
-from tkinter import _tkinter as tk
+
+tk = getattr(tkinter, "_tkinter")
 
 try:
     if hasattr(sys, "pypy_find_executable"):

src/PIL/_typing.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
+import os
 import sys
+from typing import Protocol, Sequence, TypeVar, Union
 
 if sys.version_info >= (3, 10):
     from typing import TypeGuard
@@ -15,4 +17,17 @@ else:
                 return bool
 
 
-__all__ = ["TypeGuard"]
+Coords = Union[Sequence[float], Sequence[Sequence[float]]]
+
+
+_T_co = TypeVar("_T_co", covariant=True)
+
+
+class SupportsRead(Protocol[_T_co]):
+    def read(self, __length: int = ...) -> _T_co: ...
+
+
+StrOrBytesPath = Union[str, bytes, "os.PathLike[str]", "os.PathLike[bytes]"]
+
+
+__all__ = ["TypeGuard", "StrOrBytesPath", "SupportsRead"]

src/PIL/_util.py

@@ -1,17 +1,16 @@
 from __future__ import annotations
 
 import os
-from pathlib import Path
 from typing import Any, NoReturn
 
-from ._typing import TypeGuard
+from ._typing import StrOrBytesPath, TypeGuard
 
 
-def is_path(f: Any) -> TypeGuard[bytes | str | Path]:
+def is_path(f: Any) -> TypeGuard[StrOrBytesPath]:
-    return isinstance(f, (bytes, str, Path))
+    return isinstance(f, (bytes, str, os.PathLike))
 
 
-def is_directory(f: Any) -> TypeGuard[bytes | str | Path]:
+def is_directory(f: Any) -> TypeGuard[StrOrBytesPath]:
     """Checks if an object is a string, and that it points to a directory."""
     return is_path(f) and os.path.isdir(f)
 

src/PIL/_webp.pyi

@@ -0,0 +1,5 @@
+from __future__ import annotations
+
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

tox.ini

@@ -33,9 +33,14 @@ commands =
 [testenv:mypy]
 skip_install = true
 deps =
+    IceSpringPySideStubs-PyQt6
+    IceSpringPySideStubs-PySide6
     ipython
     mypy==1.7.1
     numpy
+    packaging
+    types-cffi
+    types-defusedxml
 extras =
     typing
 commands =