From 8a05e32336bfbece4aed16a63d009efa55a1b4bb Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Mon, 8 Jul 2024 20:09:45 +1000
Subject: [PATCH] Added type hints

---
 Tests/test_file_mpo.py       | 16 +++++++++----
 Tests/test_imagefile.py      |  5 +++-
 Tests/test_imagetk.py        |  3 +++
 src/PIL/BlpImagePlugin.py    |  1 +
 src/PIL/BmpImagePlugin.py    | 44 +++++++++++++++++++++++++-----------
 src/PIL/ImageFile.py         | 18 +++++++--------
 src/PIL/ImageTk.py           | 24 ++++++++++++++------
 src/PIL/Jpeg2KImagePlugin.py | 40 +++++++++++++++++++++++++++-----
 src/PIL/JpegImagePlugin.py   | 18 ++++++++-------
 src/PIL/MpoImagePlugin.py    | 17 ++++++++++----
 src/PIL/PngImagePlugin.py    | 42 +++++++++++++++++++++++-----------
 src/PIL/PsdImagePlugin.py    |  2 +-
 src/PIL/WebPImagePlugin.py   |  2 +-
 src/PIL/WmfImagePlugin.py    |  2 +-
 src/PIL/_imagingtk.pyi       |  3 +++
 15 files changed, 168 insertions(+), 69 deletions(-)
 create mode 100644 src/PIL/_imagingtk.pyi

diff --git a/Tests/test_file_mpo.py b/Tests/test_file_mpo.py
index 39b9c60b756..5402fcb440d 100644
--- a/Tests/test_file_mpo.py
+++ b/Tests/test_file_mpo.py
@@ -2,11 +2,11 @@
 
 import warnings
 from io import BytesIO
-from typing import Any, cast
+from typing import Any
 
 import pytest
 
-from PIL import Image, MpoImagePlugin
+from PIL import Image, ImageFile, MpoImagePlugin
 
 from .helper import (
     assert_image_equal,
@@ -20,11 +20,11 @@
 pytestmark = skip_unless_feature("jpg")
 
 
-def roundtrip(im: Image.Image, **options: Any) -> MpoImagePlugin.MpoImageFile:
+def roundtrip(im: Image.Image, **options: Any) -> ImageFile.ImageFile:
     out = BytesIO()
     im.save(out, "MPO", **options)
     out.seek(0)
-    return cast(MpoImagePlugin.MpoImageFile, Image.open(out))
+    return Image.open(out)
 
 
 @pytest.mark.parametrize("test_file", test_files)
@@ -226,6 +226,12 @@ def test_eoferror() -> None:
         im.seek(n_frames - 1)
 
 
+def test_adopt_jpeg() -> None:
+    with Image.open("Tests/images/hopper.jpg") as im:
+        with pytest.raises(ValueError):
+            MpoImagePlugin.MpoImageFile.adopt(im)
+
+
 def test_ultra_hdr() -> None:
     with Image.open("Tests/images/ultrahdr.jpg") as im:
         assert im.format == "JPEG"
@@ -275,6 +281,8 @@ def test_save_all() -> None:
     im_reloaded = roundtrip(im, save_all=True, append_images=[im2])
 
     assert_image_equal(im, im_reloaded)
+    assert isinstance(im_reloaded, MpoImagePlugin.MpoImageFile)
+    assert im_reloaded.mpinfo is not None
     assert im_reloaded.mpinfo[45056] == b"0100"
 
     im_reloaded.seek(1)
diff --git a/Tests/test_imagefile.py b/Tests/test_imagefile.py
index bb686bb3b90..b996860ce2c 100644
--- a/Tests/test_imagefile.py
+++ b/Tests/test_imagefile.py
@@ -90,6 +90,7 @@ def test_ico(self) -> None:
             data = f.read()
         with ImageFile.Parser() as p:
             p.feed(data)
+            assert p.image is not None
             assert (48, 48) == p.image.size
 
     @skip_unless_feature("webp")
@@ -103,6 +104,7 @@ def test_incremental_webp(self) -> None:
                 assert not p.image
 
                 p.feed(f.read())
+            assert p.image is not None
             assert (128, 128) == p.image.size
 
     @skip_unless_feature("zlib")
@@ -393,8 +395,9 @@ def test_encode(self) -> None:
         with pytest.raises(NotImplementedError):
             encoder.encode_to_pyfd()
 
+        fh = BytesIO()
         with pytest.raises(NotImplementedError):
-            encoder.encode_to_file(None, None)
+            encoder.encode_to_file(fh, 0)
 
     def test_zero_height(self) -> None:
         with pytest.raises(UnidentifiedImageError):
diff --git a/Tests/test_imagetk.py b/Tests/test_imagetk.py
index f84c6c03a37..4484dca1064 100644
--- a/Tests/test_imagetk.py
+++ b/Tests/test_imagetk.py
@@ -109,3 +109,6 @@ def test_bitmapimage() -> None:
 
     # reloaded = ImageTk.getimage(im_tk)
     # assert_image_equal(reloaded, im)
+
+    with pytest.raises(ValueError):
+        ImageTk.BitmapImage()
diff --git a/src/PIL/BlpImagePlugin.py b/src/PIL/BlpImagePlugin.py
index b9cefafdd07..6d71049a9d5 100644
--- a/src/PIL/BlpImagePlugin.py
+++ b/src/PIL/BlpImagePlugin.py
@@ -313,6 +313,7 @@ def _read_blp_header(self) -> None:
         self._blp_lengths = struct.unpack("<16I", self._safe_read(16 * 4))
 
     def _safe_read(self, length: int) -> bytes:
+        assert self.fd is not None
         return ImageFile._safe_read(self.fd, length)
 
     def _read_palette(self) -> list[tuple[int, int, int, int]]:
diff --git a/src/PIL/BmpImagePlugin.py b/src/PIL/BmpImagePlugin.py
index ef204533712..48bdd98307c 100644
--- a/src/PIL/BmpImagePlugin.py
+++ b/src/PIL/BmpImagePlugin.py
@@ -25,7 +25,7 @@
 from __future__ import annotations
 
 import os
-from typing import IO
+from typing import IO, Any
 
 from . import Image, ImageFile, ImagePalette
 from ._binary import i16le as i16
@@ -72,16 +72,20 @@ class BmpImageFile(ImageFile.ImageFile):
     for k, v in COMPRESSIONS.items():
         vars()[k] = v
 
-    def _bitmap(self, header=0, offset=0):
+    def _bitmap(self, header: int = 0, offset: int = 0) -> None:
         """Read relevant info about the BMP"""
         read, seek = self.fp.read, self.fp.seek
         if header:
             seek(header)
         # read bmp header size @offset 14 (this is part of the header size)
-        file_info = {"header_size": i32(read(4)), "direction": -1}
+        file_info: dict[str, bool | int | tuple[int, ...]] = {
+            "header_size": i32(read(4)),
+            "direction": -1,
+        }
 
         # -------------------- If requested, read header at a specific position
         # read the rest of the bmp header, without its size
+        assert isinstance(file_info["header_size"], int)
         header_data = ImageFile._safe_read(self.fp, file_info["header_size"] - 4)
 
         # ------------------------------- Windows Bitmap v2, IBM OS/2 Bitmap v1
@@ -92,7 +96,7 @@ def _bitmap(self, header=0, offset=0):
             file_info["height"] = i16(header_data, 2)
             file_info["planes"] = i16(header_data, 4)
             file_info["bits"] = i16(header_data, 6)
-            file_info["compression"] = self.RAW
+            file_info["compression"] = self.COMPRESSIONS["RAW"]
             file_info["palette_padding"] = 3
 
         # --------------------------------------------- Windows Bitmap v3 to v5
@@ -122,8 +126,9 @@ def _bitmap(self, header=0, offset=0):
             )
             file_info["colors"] = i32(header_data, 28)
             file_info["palette_padding"] = 4
+            assert isinstance(file_info["pixels_per_meter"], tuple)
             self.info["dpi"] = tuple(x / 39.3701 for x in file_info["pixels_per_meter"])
-            if file_info["compression"] == self.BITFIELDS:
+            if file_info["compression"] == self.COMPRESSIONS["BITFIELDS"]:
                 masks = ["r_mask", "g_mask", "b_mask"]
                 if len(header_data) >= 48:
                     if len(header_data) >= 52:
@@ -144,6 +149,10 @@ def _bitmap(self, header=0, offset=0):
                     file_info["a_mask"] = 0x0
                     for mask in masks:
                         file_info[mask] = i32(read(4))
+                assert isinstance(file_info["r_mask"], int)
+                assert isinstance(file_info["g_mask"], int)
+                assert isinstance(file_info["b_mask"], int)
+                assert isinstance(file_info["a_mask"], int)
                 file_info["rgb_mask"] = (
                     file_info["r_mask"],
                     file_info["g_mask"],
@@ -164,24 +173,26 @@ def _bitmap(self, header=0, offset=0):
         self._size = file_info["width"], file_info["height"]
 
         # ------- If color count was not found in the header, compute from bits
+        assert isinstance(file_info["bits"], int)
         file_info["colors"] = (
             file_info["colors"]
             if file_info.get("colors", 0)
             else (1 << file_info["bits"])
         )
+        assert isinstance(file_info["colors"], int)
         if offset == 14 + file_info["header_size"] and file_info["bits"] <= 8:
             offset += 4 * file_info["colors"]
 
         # ---------------------- Check bit depth for unusual unsupported values
-        self._mode, raw_mode = BIT2MODE.get(file_info["bits"], (None, None))
-        if self.mode is None:
+        self._mode, raw_mode = BIT2MODE.get(file_info["bits"], ("", ""))
+        if not self.mode:
             msg = f"Unsupported BMP pixel depth ({file_info['bits']})"
             raise OSError(msg)
 
         # ---------------- Process BMP with Bitfields compression (not palette)
         decoder_name = "raw"
-        if file_info["compression"] == self.BITFIELDS:
-            SUPPORTED = {
+        if file_info["compression"] == self.COMPRESSIONS["BITFIELDS"]:
+            SUPPORTED: dict[int, list[tuple[int, ...]]] = {
                 32: [
                     (0xFF0000, 0xFF00, 0xFF, 0x0),
                     (0xFF000000, 0xFF0000, 0xFF00, 0x0),
@@ -213,12 +224,14 @@ def _bitmap(self, header=0, offset=0):
                     file_info["bits"] == 32
                     and file_info["rgba_mask"] in SUPPORTED[file_info["bits"]]
                 ):
+                    assert isinstance(file_info["rgba_mask"], tuple)
                     raw_mode = MASK_MODES[(file_info["bits"], file_info["rgba_mask"])]
                     self._mode = "RGBA" if "A" in raw_mode else self.mode
                 elif (
                     file_info["bits"] in (24, 16)
                     and file_info["rgb_mask"] in SUPPORTED[file_info["bits"]]
                 ):
+                    assert isinstance(file_info["rgb_mask"], tuple)
                     raw_mode = MASK_MODES[(file_info["bits"], file_info["rgb_mask"])]
                 else:
                     msg = "Unsupported BMP bitfields layout"
@@ -226,10 +239,13 @@ def _bitmap(self, header=0, offset=0):
             else:
                 msg = "Unsupported BMP bitfields layout"
                 raise OSError(msg)
-        elif file_info["compression"] == self.RAW:
+        elif file_info["compression"] == self.COMPRESSIONS["RAW"]:
             if file_info["bits"] == 32 and header == 22:  # 32-bit .cur offset
                 raw_mode, self._mode = "BGRA", "RGBA"
-        elif file_info["compression"] in (self.RLE8, self.RLE4):
+        elif file_info["compression"] in (
+            self.COMPRESSIONS["RLE8"],
+            self.COMPRESSIONS["RLE4"],
+        ):
             decoder_name = "bmp_rle"
         else:
             msg = f"Unsupported BMP compression ({file_info['compression']})"
@@ -242,6 +258,7 @@ def _bitmap(self, header=0, offset=0):
                 msg = f"Unsupported BMP Palette size ({file_info['colors']})"
                 raise OSError(msg)
             else:
+                assert isinstance(file_info["palette_padding"], int)
                 padding = file_info["palette_padding"]
                 palette = read(padding * file_info["colors"])
                 grayscale = True
@@ -269,10 +286,11 @@ def _bitmap(self, header=0, offset=0):
 
         # ---------------------------- Finally set the tile data for the plugin
         self.info["compression"] = file_info["compression"]
-        args = [raw_mode]
+        args: list[Any] = [raw_mode]
         if decoder_name == "bmp_rle":
-            args.append(file_info["compression"] == self.RLE4)
+            args.append(file_info["compression"] == self.COMPRESSIONS["RLE4"])
         else:
+            assert isinstance(file_info["width"], int)
             args.append(((file_info["width"] * file_info["bits"] + 31) >> 3) & (~3))
         args.append(file_info["direction"])
         self.tile = [
diff --git a/src/PIL/ImageFile.py b/src/PIL/ImageFile.py
index 69e7ee54811..99d7e73f111 100644
--- a/src/PIL/ImageFile.py
+++ b/src/PIL/ImageFile.py
@@ -485,7 +485,7 @@ def feed(self, data):
 
                 self.image = im
 
-    def __enter__(self):
+    def __enter__(self) -> Parser:
         return self
 
     def __exit__(self, *args: object) -> None:
@@ -580,7 +580,7 @@ def _encode_tile(im, fp, tile: list[_Tile], bufsize, fh, exc=None):
             encoder.cleanup()
 
 
-def _safe_read(fp, size):
+def _safe_read(fp: IO[bytes], size: int) -> bytes:
     """
     Reads large blocks in a safe way.  Unlike fp.read(n), this function
     doesn't trust the user.  If the requested size is larger than
@@ -601,18 +601,18 @@ def _safe_read(fp, size):
             msg = "Truncated File Read"
             raise OSError(msg)
         return data
-    data = []
+    blocks: list[bytes] = []
     remaining_size = size
     while remaining_size > 0:
         block = fp.read(min(remaining_size, SAFEBLOCK))
         if not block:
             break
-        data.append(block)
+        blocks.append(block)
         remaining_size -= len(block)
-    if sum(len(d) for d in data) < size:
+    if sum(len(block) for block in blocks) < size:
         msg = "Truncated File Read"
         raise OSError(msg)
-    return b"".join(data)
+    return b"".join(blocks)
 
 
 class PyCodecState:
@@ -636,7 +636,7 @@ def __init__(self, mode, *args):
         self.mode = mode
         self.init(args)
 
-    def init(self, args):
+    def init(self, args) -> None:
         """
         Override to perform codec specific initialization
 
@@ -653,7 +653,7 @@ def cleanup(self) -> None:
         """
         pass
 
-    def setfd(self, fd):
+    def setfd(self, fd) -> None:
         """
         Called from ImageFile to set the Python file-like object
 
@@ -793,7 +793,7 @@ def encode_to_pyfd(self) -> tuple[int, int]:
             self.fd.write(data)
         return bytes_consumed, errcode
 
-    def encode_to_file(self, fh, bufsize):
+    def encode_to_file(self, fh: IO[bytes], bufsize: int) -> int:
         """
         :param fh: File handle.
         :param bufsize: Buffer size.
diff --git a/src/PIL/ImageTk.py b/src/PIL/ImageTk.py
index 6aa70ced3e6..6b13e57a076 100644
--- a/src/PIL/ImageTk.py
+++ b/src/PIL/ImageTk.py
@@ -28,7 +28,7 @@
 
 import tkinter
 from io import BytesIO
-from typing import Any
+from typing import TYPE_CHECKING, Any, cast
 
 from . import Image, ImageFile
 
@@ -61,7 +61,9 @@ def _get_image_from_kw(kw: dict[str, Any]) -> ImageFile.ImageFile | None:
     return Image.open(source)
 
 
-def _pyimagingtkcall(command, photo, id):
+def _pyimagingtkcall(
+    command: str, photo: PhotoImage | tkinter.PhotoImage, id: int
+) -> None:
     tk = photo.tk
     try:
         tk.call(command, photo, id)
@@ -215,11 +217,14 @@ class BitmapImage:
     :param image: A PIL image.
     """
 
-    def __init__(self, image=None, **kw):
+    def __init__(self, image: Image.Image | None = None, **kw: Any) -> None:
         # Tk compatibility: file or data
         if image is None:
             image = _get_image_from_kw(kw)
 
+        if image is None:
+            msg = "Image is required"
+            raise ValueError(msg)
         self.__mode = image.mode
         self.__size = image.size
 
@@ -278,18 +283,23 @@ def getimage(photo: PhotoImage) -> Image.Image:
     return im
 
 
-def _show(image, title):
+def _show(image: Image.Image, title: str | None) -> None:
     """Helper for the Image.show method."""
 
     class UI(tkinter.Label):
-        def __init__(self, master, im):
+        def __init__(self, master: tkinter.Toplevel, im: Image.Image) -> None:
+            self.image: BitmapImage | PhotoImage
             if im.mode == "1":
                 self.image = BitmapImage(im, foreground="white", master=master)
             else:
                 self.image = PhotoImage(im, master=master)
-            super().__init__(master, image=self.image, bg="black", bd=0)
+            if TYPE_CHECKING:
+                image = cast(tkinter._Image, self.image)
+            else:
+                image = self.image
+            super().__init__(master, image=image, bg="black", bd=0)
 
-    if not tkinter._default_root:
+    if not getattr(tkinter, "_default_root"):
         msg = "tkinter not initialized"
         raise OSError(msg)
     top = tkinter.Toplevel()
diff --git a/src/PIL/Jpeg2KImagePlugin.py b/src/PIL/Jpeg2KImagePlugin.py
index 992b9ccaf31..eeec41686ca 100644
--- a/src/PIL/Jpeg2KImagePlugin.py
+++ b/src/PIL/Jpeg2KImagePlugin.py
@@ -29,7 +29,7 @@ class BoxReader:
     and to easily step into and read sub-boxes.
     """
 
-    def __init__(self, fp, length=-1):
+    def __init__(self, fp: IO[bytes], length: int = -1) -> None:
         self.fp = fp
         self.has_length = length >= 0
         self.length = length
@@ -97,7 +97,7 @@ def next_box_type(self) -> bytes:
         return tbox
 
 
-def _parse_codestream(fp) -> tuple[tuple[int, int], str]:
+def _parse_codestream(fp: IO[bytes]) -> tuple[tuple[int, int], str]:
     """Parse the JPEG 2000 codestream to extract the size and component
     count from the SIZ marker segment, returning a PIL (size, mode) tuple."""
 
@@ -137,7 +137,15 @@ def _res_to_dpi(num: int, denom: int, exp: int) -> float | None:
     return (254 * num * (10**exp)) / (10000 * denom)
 
 
-def _parse_jp2_header(fp):
+def _parse_jp2_header(
+    fp: IO[bytes],
+) -> tuple[
+    tuple[int, int],
+    str,
+    str | None,
+    tuple[float, float] | None,
+    ImagePalette.ImagePalette | None,
+]:
     """Parse the JP2 header box to extract size, component count,
     color space information, and optionally DPI information,
     returning a (size, mode, mimetype, dpi) tuple."""
@@ -155,6 +163,7 @@ def _parse_jp2_header(fp):
         elif tbox == b"ftyp":
             if reader.read_fields(">4s")[0] == b"jpx ":
                 mimetype = "image/jpx"
+    assert header is not None
 
     size = None
     mode = None
@@ -168,6 +177,9 @@ def _parse_jp2_header(fp):
 
         if tbox == b"ihdr":
             height, width, nc, bpc = header.read_fields(">IIHB")
+            assert isinstance(height, int)
+            assert isinstance(width, int)
+            assert isinstance(bpc, int)
             size = (width, height)
             if nc == 1 and (bpc & 0x7F) > 8:
                 mode = "I;16"
@@ -185,11 +197,21 @@ def _parse_jp2_header(fp):
                 mode = "CMYK"
         elif tbox == b"pclr" and mode in ("L", "LA"):
             ne, npc = header.read_fields(">HB")
-            bitdepths = header.read_fields(">" + ("B" * npc))
-            if max(bitdepths) <= 8:
+            assert isinstance(ne, int)
+            assert isinstance(npc, int)
+            max_bitdepth = 0
+            for bitdepth in header.read_fields(">" + ("B" * npc)):
+                assert isinstance(bitdepth, int)
+                if bitdepth > max_bitdepth:
+                    max_bitdepth = bitdepth
+            if max_bitdepth <= 8:
                 palette = ImagePalette.ImagePalette()
                 for i in range(ne):
-                    palette.getcolor(header.read_fields(">" + ("B" * npc)))
+                    color: list[int] = []
+                    for value in header.read_fields(">" + ("B" * npc)):
+                        assert isinstance(value, int)
+                        color.append(value)
+                    palette.getcolor(tuple(color))
                 mode = "P" if mode == "L" else "PA"
         elif tbox == b"res ":
             res = header.read_boxes()
@@ -197,6 +219,12 @@ def _parse_jp2_header(fp):
                 tres = res.next_box_type()
                 if tres == b"resc":
                     vrcn, vrcd, hrcn, hrcd, vrce, hrce = res.read_fields(">HHHHBB")
+                    assert isinstance(vrcn, int)
+                    assert isinstance(vrcd, int)
+                    assert isinstance(hrcn, int)
+                    assert isinstance(hrcd, int)
+                    assert isinstance(vrce, int)
+                    assert isinstance(hrce, int)
                     hres = _res_to_dpi(hrcn, hrcd, hrce)
                     vres = _res_to_dpi(vrcn, vrcd, vrce)
                     if hres is not None and vres is not None:
diff --git a/src/PIL/JpegImagePlugin.py b/src/PIL/JpegImagePlugin.py
index b15bf06d2b1..4916727beae 100644
--- a/src/PIL/JpegImagePlugin.py
+++ b/src/PIL/JpegImagePlugin.py
@@ -60,7 +60,7 @@ def Skip(self: JpegImageFile, marker: int) -> None:
     ImageFile._safe_read(self.fp, n)
 
 
-def APP(self, marker):
+def APP(self: JpegImageFile, marker: int) -> None:
     #
     # Application marker.  Store these in the APP dictionary.
     # Also look for well-known application markers.
@@ -133,13 +133,14 @@ def APP(self, marker):
                 offset += 4
                 data = s[offset : offset + size]
                 if code == 0x03ED:  # ResolutionInfo
-                    data = {
+                    photoshop[code] = {
                         "XResolution": i32(data, 0) / 65536,
                         "DisplayedUnitsX": i16(data, 4),
                         "YResolution": i32(data, 8) / 65536,
                         "DisplayedUnitsY": i16(data, 12),
                     }
-                photoshop[code] = data
+                else:
+                    photoshop[code] = data
                 offset += size
                 offset += offset & 1  # align
             except struct.error:
@@ -338,6 +339,7 @@ def _open(self):
 
         # Create attributes
         self.bits = self.layers = 0
+        self._exif_offset = 0
 
         # JPEG specifics (internal)
         self.layer = []
@@ -498,17 +500,17 @@ def _read_dpi_from_exif(self) -> None:
         ):
             self.info["dpi"] = 72, 72
 
-    def _getmp(self):
+    def _getmp(self) -> dict[int, Any] | None:
         return _getmp(self)
 
 
-def _getexif(self) -> dict[str, Any] | None:
+def _getexif(self: JpegImageFile) -> dict[str, Any] | None:
     if "exif" not in self.info:
         return None
     return self.getexif()._get_merged_dict()
 
 
-def _getmp(self):
+def _getmp(self: JpegImageFile) -> dict[int, Any] | None:
     # Extract MP information.  This method was inspired by the "highly
     # experimental" _getexif version that's been in use for years now,
     # itself based on the ImageFileDirectory class in the TIFF plugin.
@@ -616,7 +618,7 @@ def _getmp(self):
 # fmt: on
 
 
-def get_sampling(im):
+def get_sampling(im: Image.Image) -> int:
     # There's no subsampling when images have only 1 layer
     # (grayscale images) or when they are CMYK (4 layers),
     # so set subsampling to the default value.
@@ -624,7 +626,7 @@ def get_sampling(im):
     # NOTE: currently Pillow can't encode JPEG to YCCK format.
     # If YCCK support is added in the future, subsampling code will have
     # to be updated (here and in JpegEncode.c) to deal with 4 layers.
-    if not hasattr(im, "layers") or im.layers in (1, 4):
+    if not isinstance(im, JpegImageFile) or im.layers in (1, 4):
         return -1
     sampling = im.layer[0][1:3] + im.layer[1][1:3] + im.layer[2][1:3]
     return samplings.get(sampling, -1)
diff --git a/src/PIL/MpoImagePlugin.py b/src/PIL/MpoImagePlugin.py
index f21570661f8..5ed9f56a164 100644
--- a/src/PIL/MpoImagePlugin.py
+++ b/src/PIL/MpoImagePlugin.py
@@ -22,7 +22,7 @@
 import itertools
 import os
 import struct
-from typing import IO
+from typing import IO, Any, cast
 
 from . import (
     Image,
@@ -101,8 +101,11 @@ def _open(self) -> None:
         JpegImagePlugin.JpegImageFile._open(self)
         self._after_jpeg_open()
 
-    def _after_jpeg_open(self, mpheader=None):
+    def _after_jpeg_open(self, mpheader: dict[int, Any] | None = None) -> None:
         self.mpinfo = mpheader if mpheader is not None else self._getmp()
+        if self.mpinfo is None:
+            msg = "Image appears to be a malformed MPO file"
+            raise ValueError(msg)
         self.n_frames = self.mpinfo[0xB001]
         self.__mpoffsets = [
             mpent["DataOffset"] + self.info["mpoffset"] for mpent in self.mpinfo[0xB002]
@@ -149,7 +152,10 @@ def tell(self) -> int:
         return self.__frame
 
     @staticmethod
-    def adopt(jpeg_instance, mpheader=None):
+    def adopt(
+        jpeg_instance: JpegImagePlugin.JpegImageFile,
+        mpheader: dict[int, Any] | None = None,
+    ) -> MpoImageFile:
         """
         Transform the instance of JpegImageFile into
         an instance of MpoImageFile.
@@ -161,8 +167,9 @@ def adopt(jpeg_instance, mpheader=None):
         double call to _open.
         """
         jpeg_instance.__class__ = MpoImageFile
-        jpeg_instance._after_jpeg_open(mpheader)
-        return jpeg_instance
+        mpo_instance = cast(MpoImageFile, jpeg_instance)
+        mpo_instance._after_jpeg_open(mpheader)
+        return mpo_instance
 
 
 # ---------------------------------------------------------------------
diff --git a/src/PIL/PngImagePlugin.py b/src/PIL/PngImagePlugin.py
index 34ea77c5e01..fa117d19ae1 100644
--- a/src/PIL/PngImagePlugin.py
+++ b/src/PIL/PngImagePlugin.py
@@ -230,6 +230,7 @@ def verify(self, endchunk: bytes = b"IEND") -> list[bytes]:
 
         cids = []
 
+        assert self.fp is not None
         while True:
             try:
                 cid, pos, length = self.read()
@@ -407,6 +408,7 @@ def rewind(self) -> None:
 
     def chunk_iCCP(self, pos: int, length: int) -> bytes:
         # ICC profile
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         # according to PNG spec, the iCCP chunk contains:
         # Profile name  1-79 bytes (character string)
@@ -434,6 +436,7 @@ def chunk_iCCP(self, pos: int, length: int) -> bytes:
 
     def chunk_IHDR(self, pos: int, length: int) -> bytes:
         # image header
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         if length < 13:
             if ImageFile.LOAD_TRUNCATED_IMAGES:
@@ -471,6 +474,7 @@ def chunk_IEND(self, pos: int, length: int) -> NoReturn:
 
     def chunk_PLTE(self, pos: int, length: int) -> bytes:
         # palette
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         if self.im_mode == "P":
             self.im_palette = "RGB", s
@@ -478,6 +482,7 @@ def chunk_PLTE(self, pos: int, length: int) -> bytes:
 
     def chunk_tRNS(self, pos: int, length: int) -> bytes:
         # transparency
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         if self.im_mode == "P":
             if _simple_palette.match(s):
@@ -498,6 +503,7 @@ def chunk_tRNS(self, pos: int, length: int) -> bytes:
 
     def chunk_gAMA(self, pos: int, length: int) -> bytes:
         # gamma setting
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         self.im_info["gamma"] = i32(s) / 100000.0
         return s
@@ -506,6 +512,7 @@ def chunk_cHRM(self, pos: int, length: int) -> bytes:
         # chromaticity, 8 unsigned ints, actual value is scaled by 100,000
         # WP x,y, Red x,y, Green x,y Blue x,y
 
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         raw_vals = struct.unpack(">%dI" % (len(s) // 4), s)
         self.im_info["chromaticity"] = tuple(elt / 100000.0 for elt in raw_vals)
@@ -518,6 +525,7 @@ def chunk_sRGB(self, pos: int, length: int) -> bytes:
         # 2 saturation
         # 3 absolute colorimetric
 
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         if length < 1:
             if ImageFile.LOAD_TRUNCATED_IMAGES:
@@ -529,6 +537,7 @@ def chunk_sRGB(self, pos: int, length: int) -> bytes:
 
     def chunk_pHYs(self, pos: int, length: int) -> bytes:
         # pixels per unit
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         if length < 9:
             if ImageFile.LOAD_TRUNCATED_IMAGES:
@@ -546,6 +555,7 @@ def chunk_pHYs(self, pos: int, length: int) -> bytes:
 
     def chunk_tEXt(self, pos: int, length: int) -> bytes:
         # text
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         try:
             k, v = s.split(b"\0", 1)
@@ -554,17 +564,18 @@ def chunk_tEXt(self, pos: int, length: int) -> bytes:
             k = s
             v = b""
         if k:
-            k = k.decode("latin-1", "strict")
+            k_str = k.decode("latin-1", "strict")
             v_str = v.decode("latin-1", "replace")
 
-            self.im_info[k] = v if k == "exif" else v_str
-            self.im_text[k] = v_str
+            self.im_info[k_str] = v if k == b"exif" else v_str
+            self.im_text[k_str] = v_str
             self.check_text_memory(len(v_str))
 
         return s
 
     def chunk_zTXt(self, pos: int, length: int) -> bytes:
         # compressed text
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         try:
             k, v = s.split(b"\0", 1)
@@ -589,16 +600,17 @@ def chunk_zTXt(self, pos: int, length: int) -> bytes:
             v = b""
 
         if k:
-            k = k.decode("latin-1", "strict")
-            v = v.decode("latin-1", "replace")
+            k_str = k.decode("latin-1", "strict")
+            v_str = v.decode("latin-1", "replace")
 
-            self.im_info[k] = self.im_text[k] = v
-            self.check_text_memory(len(v))
+            self.im_info[k_str] = self.im_text[k_str] = v_str
+            self.check_text_memory(len(v_str))
 
         return s
 
     def chunk_iTXt(self, pos: int, length: int) -> bytes:
         # international text
+        assert self.fp is not None
         r = s = ImageFile._safe_read(self.fp, length)
         try:
             k, r = r.split(b"\0", 1)
@@ -627,25 +639,27 @@ def chunk_iTXt(self, pos: int, length: int) -> bytes:
         if k == b"XML:com.adobe.xmp":
             self.im_info["xmp"] = v
         try:
-            k = k.decode("latin-1", "strict")
-            lang = lang.decode("utf-8", "strict")
-            tk = tk.decode("utf-8", "strict")
-            v = v.decode("utf-8", "strict")
+            k_str = k.decode("latin-1", "strict")
+            lang_str = lang.decode("utf-8", "strict")
+            tk_str = tk.decode("utf-8", "strict")
+            v_str = v.decode("utf-8", "strict")
         except UnicodeError:
             return s
 
-        self.im_info[k] = self.im_text[k] = iTXt(v, lang, tk)
-        self.check_text_memory(len(v))
+        self.im_info[k_str] = self.im_text[k_str] = iTXt(v_str, lang_str, tk_str)
+        self.check_text_memory(len(v_str))
 
         return s
 
     def chunk_eXIf(self, pos: int, length: int) -> bytes:
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         self.im_info["exif"] = b"Exif\x00\x00" + s
         return s
 
     # APNG chunks
     def chunk_acTL(self, pos: int, length: int) -> bytes:
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         if length < 8:
             if ImageFile.LOAD_TRUNCATED_IMAGES:
@@ -666,6 +680,7 @@ def chunk_acTL(self, pos: int, length: int) -> bytes:
         return s
 
     def chunk_fcTL(self, pos: int, length: int) -> bytes:
+        assert self.fp is not None
         s = ImageFile._safe_read(self.fp, length)
         if length < 26:
             if ImageFile.LOAD_TRUNCATED_IMAGES:
@@ -695,6 +710,7 @@ def chunk_fcTL(self, pos: int, length: int) -> bytes:
         return s
 
     def chunk_fdAT(self, pos: int, length: int) -> bytes:
+        assert self.fp is not None
         if length < 4:
             if ImageFile.LOAD_TRUNCATED_IMAGES:
                 s = ImageFile._safe_read(self.fp, length)
diff --git a/src/PIL/PsdImagePlugin.py b/src/PIL/PsdImagePlugin.py
index edf698bf02d..31dfd4d1234 100644
--- a/src/PIL/PsdImagePlugin.py
+++ b/src/PIL/PsdImagePlugin.py
@@ -185,7 +185,7 @@ def _layerinfo(fp, ct_bytes):
     # read layerinfo block
     layers = []
 
-    def read(size):
+    def read(size: int) -> bytes:
         return ImageFile._safe_read(fp, size)
 
     ct = si16(read(2))
diff --git a/src/PIL/WebPImagePlugin.py b/src/PIL/WebPImagePlugin.py
index 530b88c8bd6..011de9c6ac0 100644
--- a/src/PIL/WebPImagePlugin.py
+++ b/src/PIL/WebPImagePlugin.py
@@ -115,7 +115,7 @@ def _reset(self, reset: bool = True) -> None:
         self.__loaded = -1
         self.__timestamp = 0
 
-    def _get_next(self):
+    def _get_next(self) -> tuple[bytes, int, int]:
         # Get next frame
         ret = self._decoder.get_next()
         self.__physical_frame += 1
diff --git a/src/PIL/WmfImagePlugin.py b/src/PIL/WmfImagePlugin.py
index 3d5cddcc8f5..68f8a74f599 100644
--- a/src/PIL/WmfImagePlugin.py
+++ b/src/PIL/WmfImagePlugin.py
@@ -152,7 +152,7 @@ def _open(self) -> None:
     def _load(self) -> ImageFile.StubHandler | None:
         return _handler
 
-    def load(self, dpi=None):
+    def load(self, dpi: int | None = None) -> Image.core.PixelAccess | None:
         if dpi is not None and self._inch is not None:
             self.info["dpi"] = dpi
             x0, y0, x1, y1 = self.info["wmf_bbox"]
diff --git a/src/PIL/_imagingtk.pyi b/src/PIL/_imagingtk.pyi
new file mode 100644
index 00000000000..e27843e5338
--- /dev/null
+++ b/src/PIL/_imagingtk.pyi
@@ -0,0 +1,3 @@
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...