Added type hints

src/PIL/Image.py

@@ -1430,7 +1430,7 @@ class Image:
             root = ElementTree.fromstring(xmp_tags)
             return {get_name(root.tag): get_value(root)}
 
-    def getexif(self):
+    def getexif(self) -> Exif:
         """
         Gets EXIF data from the image.
 
@@ -1438,7 +1438,6 @@ class Image:
         """
         if self._exif is None:
             self._exif = Exif()
-            self._exif._loaded = False
         elif self._exif._loaded:
             return self._exif
         self._exif._loaded = True
@@ -1525,7 +1524,7 @@ class Image:
         self.load()
         return self.im.ptr
 
-    def getpalette(self, rawmode="RGB"):
+    def getpalette(self, rawmode: str | None = "RGB") -> list[int] | None:
         """
         Returns the image palette as a list.
 
@@ -1615,7 +1614,7 @@ class Image:
         x, y = self.im.getprojection()
         return list(x), list(y)
 
-    def histogram(self, mask=None, extrema=None):
+    def histogram(self, mask=None, extrema=None) -> list[int]:
         """
         Returns a histogram for the image. The histogram is returned as a
         list of pixel counts, one for each pixel value in the source
@@ -1804,7 +1803,7 @@ class Image:
         result = alpha_composite(background, overlay)
         self.paste(result, box)
 
-    def point(self, lut, mode=None):
+    def point(self, lut, mode: str | None = None) -> Image:
         """
         Maps this image through a lookup table or function.
 
@@ -1928,7 +1927,7 @@ class Image:
 
         self.im.putdata(data, scale, offset)
 
-    def putpalette(self, data, rawmode="RGB"):
+    def putpalette(self, data, rawmode="RGB") -> None:
         """
         Attaches a palette to this image.  The image must be a "P", "PA", "L"
         or "LA" image.
@@ -2108,7 +2107,7 @@ class Image:
             min(self.size[1], math.ceil(box[3] + support_y)),
         )
 
-    def resize(self, size, resample=None, box=None, reducing_gap=None):
+    def resize(self, size, resample=None, box=None, reducing_gap=None) -> Image:
         """
         Returns a resized copy of this image.
 
@@ -2200,10 +2199,11 @@ class Image:
             if factor_x > 1 or factor_y > 1:
                 reduce_box = self._get_safe_box(size, resample, box)
                 factor = (factor_x, factor_y)
-                if callable(self.reduce):
+                self = (
-                    self = self.reduce(factor, box=reduce_box)
+                    self.reduce(factor, box=reduce_box)
-                else:
+                    if callable(self.reduce)
-                    self = Image.reduce(self, factor, box=reduce_box)
+                    else Image.reduce(self, factor, box=reduce_box)
+                )
                 box = (
                     (box[0] - reduce_box[0]) / factor_x,
                     (box[1] - reduce_box[1]) / factor_y,
@@ -2818,7 +2818,7 @@ class Image:
 
         self.im.transform2(box, image.im, method, data, resample, fill)
 
-    def transpose(self, method):
+    def transpose(self, method: Transpose) -> Image:
         """
         Transpose image (flip or rotate in 90 degree steps)
 
@@ -2870,7 +2870,9 @@ class ImagePointHandler:
     (for use with :py:meth:`~PIL.Image.Image.point`)
     """
 
-    pass
+    @abc.abstractmethod
+    def point(self, im: Image) -> Image:
+        pass
 
 
 class ImageTransformHandler:
@@ -3690,6 +3692,7 @@ class Exif(_ExifBase):
 
     endian = None
     bigtiff = False
+    _loaded = False
 
     def __init__(self):
         self._data = {}
@@ -3805,7 +3808,7 @@ class Exif(_ExifBase):
 
         return merged_dict
 
-    def tobytes(self, offset=8):
+    def tobytes(self, offset: int = 8) -> bytes:
         from . import TiffImagePlugin
 
         head = self._get_head()
@@ -3960,7 +3963,7 @@ class Exif(_ExifBase):
             del self._info[tag]
         self._data[tag] = value
 
-    def __delitem__(self, tag):
+    def __delitem__(self, tag: int) -> None:
         if self._info is not None and tag in self._info:
             del self._info[tag]
         else:

src/PIL/ImageColor.py

@@ -124,7 +124,7 @@ def getrgb(color):
 
 
 @lru_cache
-def getcolor(color, mode):
+def getcolor(color, mode: str) -> tuple[int, ...]:
     """
     Same as :py:func:`~PIL.ImageColor.getrgb` for most modes. However, if
     ``mode`` is HSV, converts the RGB value to a HSV value, or if ``mode`` is

src/PIL/ImageOps.py

@@ -21,6 +21,7 @@ from __future__ import annotations
 import functools
 import operator
 import re
+from typing import Protocol, Sequence, cast
 
 from . import ExifTags, Image, ImagePalette
 
@@ -28,7 +29,7 @@ from . import ExifTags, Image, ImagePalette
 # helpers
 
 
-def _border(border):
+def _border(border: int | tuple[int, ...]) -> tuple[int, int, int, int]:
     if isinstance(border, tuple):
         if len(border) == 2:
             left, top = right, bottom = border
@@ -39,7 +40,7 @@ def _border(border):
     return left, top, right, bottom
 
 
-def _color(color, mode):
+def _color(color: str | int | tuple[int, ...], mode: str) -> int | tuple[int, ...]:
     if isinstance(color, str):
         from . import ImageColor
 
@@ -47,7 +48,7 @@ def _color(color, mode):
     return color
 
 
-def _lut(image, lut):
+def _lut(image: Image.Image, lut: list[int]) -> Image.Image:
     if image.mode == "P":
         # FIXME: apply to lookup table, not image data
         msg = "mode P support coming soon"
@@ -65,7 +66,13 @@ def _lut(image, lut):
 # actions
 
 
-def autocontrast(image, cutoff=0, ignore=None, mask=None, preserve_tone=False):
+def autocontrast(
+    image: Image.Image,
+    cutoff: float | tuple[float, float] = 0,
+    ignore: int | Sequence[int] | None = None,
+    mask: Image.Image | None = None,
+    preserve_tone: bool = False,
+) -> Image.Image:
     """
     Maximize (normalize) image contrast. This function calculates a
     histogram of the input image (or mask region), removes ``cutoff`` percent of the
@@ -97,10 +104,9 @@ def autocontrast(image, cutoff=0, ignore=None, mask=None, preserve_tone=False):
         h = histogram[layer : layer + 256]
         if ignore is not None:
             # get rid of outliers
-            try:
+            if isinstance(ignore, int):
                 h[ignore] = 0
-            except TypeError:
+            else:
-                # assume sequence
                 for ix in ignore:
                     h[ix] = 0
         if cutoff:
@@ -112,7 +118,7 @@ def autocontrast(image, cutoff=0, ignore=None, mask=None, preserve_tone=False):
             for ix in range(256):
                 n = n + h[ix]
             # remove cutoff% pixels from the low end
-            cut = n * cutoff[0] // 100
+            cut = int(n * cutoff[0] // 100)
             for lo in range(256):
                 if cut > h[lo]:
                     cut = cut - h[lo]
@@ -123,7 +129,7 @@ def autocontrast(image, cutoff=0, ignore=None, mask=None, preserve_tone=False):
                 if cut <= 0:
                     break
             # remove cutoff% samples from the high end
-            cut = n * cutoff[1] // 100
+            cut = int(n * cutoff[1] // 100)
             for hi in range(255, -1, -1):
                 if cut > h[hi]:
                     cut = cut - h[hi]
@@ -156,7 +162,15 @@ def autocontrast(image, cutoff=0, ignore=None, mask=None, preserve_tone=False):
     return _lut(image, lut)
 
 
-def colorize(image, black, white, mid=None, blackpoint=0, whitepoint=255, midpoint=127):
+def colorize(
+    image: Image.Image,
+    black: str | tuple[int, ...],
+    white: str | tuple[int, ...],
+    mid: str | int | tuple[int, ...] | None = None,
+    blackpoint: int = 0,
+    whitepoint: int = 255,
+    midpoint: int = 127,
+) -> Image.Image:
     """
     Colorize grayscale image.
     This function calculates a color wedge which maps all black pixels in
@@ -188,10 +202,9 @@ def colorize(image, black, white, mid=None, blackpoint=0, whitepoint=255, midpoi
         assert 0 <= blackpoint <= midpoint <= whitepoint <= 255
 
     # Define colors from arguments
-    black = _color(black, "RGB")
+    rgb_black = cast(Sequence[int], _color(black, "RGB"))
-    white = _color(white, "RGB")
+    rgb_white = cast(Sequence[int], _color(white, "RGB"))
-    if mid is not None:
+    rgb_mid = cast(Sequence[int], _color(mid, "RGB")) if mid is not None else None
-        mid = _color(mid, "RGB")
 
     # Empty lists for the mapping
     red = []
@@ -200,18 +213,24 @@ def colorize(image, black, white, mid=None, blackpoint=0, whitepoint=255, midpoi
 
     # Create the low-end values
     for i in range(0, blackpoint):
-        red.append(black[0])
+        red.append(rgb_black[0])
-        green.append(black[1])
+        green.append(rgb_black[1])
-        blue.append(black[2])
+        blue.append(rgb_black[2])
 
     # Create the mapping (2-color)
-    if mid is None:
+    if rgb_mid is None:
         range_map = range(0, whitepoint - blackpoint)
 
         for i in range_map:
-            red.append(black[0] + i * (white[0] - black[0]) // len(range_map))
+            red.append(
-            green.append(black[1] + i * (white[1] - black[1]) // len(range_map))
+                rgb_black[0] + i * (rgb_white[0] - rgb_black[0]) // len(range_map)
-            blue.append(black[2] + i * (white[2] - black[2]) // len(range_map))
+            )
+            green.append(
+                rgb_black[1] + i * (rgb_white[1] - rgb_black[1]) // len(range_map)
+            )
+            blue.append(
+                rgb_black[2] + i * (rgb_white[2] - rgb_black[2]) // len(range_map)
+            )
 
     # Create the mapping (3-color)
     else:
@@ -219,26 +238,36 @@ def colorize(image, black, white, mid=None, blackpoint=0, whitepoint=255, midpoi
         range_map2 = range(0, whitepoint - midpoint)
 
         for i in range_map1:
-            red.append(black[0] + i * (mid[0] - black[0]) // len(range_map1))
+            red.append(
-            green.append(black[1] + i * (mid[1] - black[1]) // len(range_map1))
+                rgb_black[0] + i * (rgb_mid[0] - rgb_black[0]) // len(range_map1)
-            blue.append(black[2] + i * (mid[2] - black[2]) // len(range_map1))
+            )
+            green.append(
+                rgb_black[1] + i * (rgb_mid[1] - rgb_black[1]) // len(range_map1)
+            )
+            blue.append(
+                rgb_black[2] + i * (rgb_mid[2] - rgb_black[2]) // len(range_map1)
+            )
         for i in range_map2:
-            red.append(mid[0] + i * (white[0] - mid[0]) // len(range_map2))
+            red.append(rgb_mid[0] + i * (rgb_white[0] - rgb_mid[0]) // len(range_map2))
-            green.append(mid[1] + i * (white[1] - mid[1]) // len(range_map2))
+            green.append(
-            blue.append(mid[2] + i * (white[2] - mid[2]) // len(range_map2))
+                rgb_mid[1] + i * (rgb_white[1] - rgb_mid[1]) // len(range_map2)
+            )
+            blue.append(rgb_mid[2] + i * (rgb_white[2] - rgb_mid[2]) // len(range_map2))
 
     # Create the high-end values
     for i in range(0, 256 - whitepoint):
-        red.append(white[0])
+        red.append(rgb_white[0])
-        green.append(white[1])
+        green.append(rgb_white[1])
-        blue.append(white[2])
+        blue.append(rgb_white[2])
 
     # Return converted image
     image = image.convert("RGB")
     return _lut(image, red + green + blue)
 
 
-def contain(image, size, method=Image.Resampling.BICUBIC):
+def contain(
+    image: Image.Image, size: tuple[int, int], method: int = Image.Resampling.BICUBIC
+) -> Image.Image:
     """
     Returns a resized version of the image, set to the maximum width and height
     within the requested size, while maintaining the original aspect ratio.
@@ -267,7 +296,9 @@ def contain(image, size, method=Image.Resampling.BICUBIC):
     return image.resize(size, resample=method)
 
 
-def cover(image, size, method=Image.Resampling.BICUBIC):
+def cover(
+    image: Image.Image, size: tuple[int, int], method: int = Image.Resampling.BICUBIC
+) -> Image.Image:
     """
     Returns a resized version of the image, so that the requested size is
     covered, while maintaining the original aspect ratio.
@@ -296,7 +327,13 @@ def cover(image, size, method=Image.Resampling.BICUBIC):
     return image.resize(size, resample=method)
 
 
-def pad(image, size, method=Image.Resampling.BICUBIC, color=None, centering=(0.5, 0.5)):
+def pad(
+    image: Image.Image,
+    size: tuple[int, int],
+    method: int = Image.Resampling.BICUBIC,
+    color: str | int | tuple[int, ...] | None = None,
+    centering: tuple[float, float] = (0.5, 0.5),
+) -> Image.Image:
     """
     Returns a resized and padded version of the image, expanded to fill the
     requested aspect ratio and size.
@@ -334,7 +371,7 @@ def pad(image, size, method=Image.Resampling.BICUBIC, color=None, centering=(0.5
     return out
 
 
-def crop(image, border=0):
+def crop(image: Image.Image, border: int = 0) -> Image.Image:
     """
     Remove border from image.  The same amount of pixels are removed
     from all four sides.  This function works on all image modes.
@@ -349,7 +386,9 @@ def crop(image, border=0):
     return image.crop((left, top, image.size[0] - right, image.size[1] - bottom))
 
 
-def scale(image, factor, resample=Image.Resampling.BICUBIC):
+def scale(
+    image: Image.Image, factor: float, resample: int = Image.Resampling.BICUBIC
+) -> Image.Image:
     """
     Returns a rescaled image by a specific factor given in parameter.
     A factor greater than 1 expands the image, between 0 and 1 contracts the
@@ -372,7 +411,19 @@ def scale(image, factor, resample=Image.Resampling.BICUBIC):
         return image.resize(size, resample)
 
 
-def deform(image, deformer, resample=Image.Resampling.BILINEAR):
+class _SupportsGetMesh(Protocol):
+    def getmesh(
+        self, image: Image.Image
+    ) -> list[
+        tuple[tuple[int, int, int, int], tuple[int, int, int, int, int, int, int, int]]
+    ]: ...
+
+
+def deform(
+    image: Image.Image,
+    deformer: _SupportsGetMesh,
+    resample: int = Image.Resampling.BILINEAR,
+) -> Image.Image:
     """
     Deform the image.
 
@@ -388,7 +439,7 @@ def deform(image, deformer, resample=Image.Resampling.BILINEAR):
     )
 
 
-def equalize(image, mask=None):
+def equalize(image: Image.Image, mask: Image.Image | None = None) -> Image.Image:
     """
     Equalize the image histogram. This function applies a non-linear
     mapping to the input image, in order to create a uniform
@@ -419,7 +470,11 @@ def equalize(image, mask=None):
     return _lut(image, lut)
 
 
-def expand(image, border=0, fill=0):
+def expand(
+    image: Image.Image,
+    border: int | tuple[int, ...] = 0,
+    fill: str | int | tuple[int, ...] = 0,
+) -> Image.Image:
     """
     Add border to the image
 
@@ -445,7 +500,13 @@ def expand(image, border=0, fill=0):
     return out
 
 
-def fit(image, size, method=Image.Resampling.BICUBIC, bleed=0.0, centering=(0.5, 0.5)):
+def fit(
+    image: Image.Image,
+    size: tuple[int, int],
+    method: int = Image.Resampling.BICUBIC,
+    bleed: float = 0.0,
+    centering: tuple[float, float] = (0.5, 0.5),
+) -> Image.Image:
     """
     Returns a resized and cropped version of the image, cropped to the
     requested aspect ratio and size.
@@ -479,13 +540,12 @@ def fit(image, size, method=Image.Resampling.BICUBIC, bleed=0.0, centering=(0.5,
     # kevin@cazabon.com
     # https://www.cazabon.com
 
-    # ensure centering is mutable
+    centering_x, centering_y = centering
-    centering = list(centering)
 
-    if not 0.0 <= centering[0] <= 1.0:
+    if not 0.0 <= centering_x <= 1.0:
-        centering[0] = 0.5
+        centering_x = 0.5
-    if not 0.0 <= centering[1] <= 1.0:
+    if not 0.0 <= centering_y <= 1.0:
-        centering[1] = 0.5
+        centering_y = 0.5
 
     if not 0.0 <= bleed < 0.5:
         bleed = 0.0
@@ -522,8 +582,8 @@ def fit(image, size, method=Image.Resampling.BICUBIC, bleed=0.0, centering=(0.5,
         crop_height = live_size[0] / output_ratio
 
     # make the crop
-    crop_left = bleed_pixels[0] + (live_size[0] - crop_width) * centering[0]
+    crop_left = bleed_pixels[0] + (live_size[0] - crop_width) * centering_x
-    crop_top = bleed_pixels[1] + (live_size[1] - crop_height) * centering[1]
+    crop_top = bleed_pixels[1] + (live_size[1] - crop_height) * centering_y
 
     crop = (crop_left, crop_top, crop_left + crop_width, crop_top + crop_height)
 
@@ -531,7 +591,7 @@ def fit(image, size, method=Image.Resampling.BICUBIC, bleed=0.0, centering=(0.5,
     return image.resize(size, method, box=crop)
 
 
-def flip(image):
+def flip(image: Image.Image) -> Image.Image:
     """
     Flip the image vertically (top to bottom).
 
@@ -541,7 +601,7 @@ def flip(image):
     return image.transpose(Image.Transpose.FLIP_TOP_BOTTOM)
 
 
-def grayscale(image):
+def grayscale(image: Image.Image) -> Image.Image:
     """
     Convert the image to grayscale.
 
@@ -551,7 +611,7 @@ def grayscale(image):
     return image.convert("L")
 
 
-def invert(image):
+def invert(image: Image.Image) -> Image.Image:
     """
     Invert (negate) the image.
 
@@ -562,7 +622,7 @@ def invert(image):
     return image.point(lut) if image.mode == "1" else _lut(image, lut)
 
 
-def mirror(image):
+def mirror(image: Image.Image) -> Image.Image:
     """
     Flip image horizontally (left to right).
 
@@ -572,7 +632,7 @@ def mirror(image):
     return image.transpose(Image.Transpose.FLIP_LEFT_RIGHT)
 
 
-def posterize(image, bits):
+def posterize(image: Image.Image, bits: int) -> Image.Image:
     """
     Reduce the number of bits for each color channel.
 
@@ -585,7 +645,7 @@ def posterize(image, bits):
     return _lut(image, lut)
 
 
-def solarize(image, threshold=128):
+def solarize(image: Image.Image, threshold: int = 128) -> Image.Image:
     """
     Invert all pixel values above a threshold.
 
@@ -602,7 +662,7 @@ def solarize(image, threshold=128):
     return _lut(image, lut)
 
 
-def exif_transpose(image, *, in_place=False):
+def exif_transpose(image: Image.Image, *, in_place: bool = False) -> Image.Image | None:
     """
     If an image has an EXIF Orientation tag, other than 1, transpose the image
     accordingly, and remove the orientation data.
@@ -616,7 +676,7 @@ def exif_transpose(image, *, in_place=False):
     """
     image.load()
     image_exif = image.getexif()
-    orientation = image_exif.get(ExifTags.Base.Orientation)
+    orientation = image_exif.get(ExifTags.Base.Orientation, 1)
     method = {
         2: Image.Transpose.FLIP_LEFT_RIGHT,
         3: Image.Transpose.ROTATE_180,
@@ -653,3 +713,4 @@ def exif_transpose(image, *, in_place=False):
             return transposed_image
     elif not in_place:
         return image.copy()
+    return None

src/PIL/ImagePalette.py

@@ -18,6 +18,7 @@
 from __future__ import annotations
 
 import array
+from typing import Sequence
 
 from . import GimpGradientFile, GimpPaletteFile, ImageColor, PaletteFile
 
@@ -34,11 +35,11 @@ class ImagePalette:
         Defaults to an empty palette.
     """
 
-    def __init__(self, mode="RGB", palette=None):
+    def __init__(self, mode: str = "RGB", palette: Sequence[int] | None = None) -> None:
         self.mode = mode
         self.rawmode = None  # if set, palette contains raw data
         self.palette = palette or bytearray()
-        self.dirty = None
+        self.dirty: int | None = None
 
     @property
     def palette(self):
@@ -127,7 +128,7 @@ class ImagePalette:
                 raise ValueError(msg) from e
         return index
 
-    def getcolor(self, color, image=None):
+    def getcolor(self, color, image=None) -> int:
         """Given an rgb tuple, allocate palette entry.
 
         .. warning:: This method is experimental.