Merge branch 'main' into main

.ci/install.sh

@@ -51,10 +51,10 @@ pushd depends && ./install_webp.sh && popd
 pushd depends && ./install_imagequant.sh && popd
 
 # raqm
-pushd depends && ./install_raqm.sh && popd
+pushd depends && sudo ./install_raqm.sh && popd
 
 # libavif
-pushd depends && ./install_libavif.sh && popd
+pushd depends && sudo ./install_libavif.sh && popd
 
 # extra test images
 pushd depends && ./install_extra_test_images.sh && popd

.ci/requirements-cibw.txt

@@ -1 +1 @@
-cibuildwheel==3.1.4
+cibuildwheel==3.2.1

.ci/requirements-mypy.txt

@@ -1,4 +1,6 @@
-mypy==1.18.1
+mypy==1.18.2
+arro3-compute
+arro3-core
 IceSpringPySideStubs-PyQt6
 IceSpringPySideStubs-PySide6
 ipython

.github/workflows/macos-install.sh

@@ -2,9 +2,6 @@
 
 set -e
 
-if [[ "$ImageOS" == "macos13" ]]; then
-    brew uninstall gradle maven
-fi
 brew install \
     aom \
     dav1d \

.github/workflows/test-windows.yml

@@ -97,8 +97,8 @@ jobs:
         choco install nasm --no-progress
         echo "C:\Program Files\NASM" >> $env:GITHUB_PATH
 
-        choco install ghostscript --version=10.5.1 --no-progress
-        echo "C:\Program Files\gs\gs10.05.1\bin" >> $env:GITHUB_PATH
+        choco install ghostscript --version=10.6.0 --no-progress
+        echo "C:\Program Files\gs\gs10.06.0\bin" >> $env:GITHUB_PATH
 
         # Install extra test images
         xcopy /S /Y Tests\test-images\* Tests\images

.github/workflows/test.yml

@@ -57,7 +57,7 @@ jobs:
         - { python-version: "3.14t", disable-gil: true }
         - { python-version: "3.13t", disable-gil: true }
         # Intel
-        - { os: "macos-13", python-version: "3.10" }
+        - { os: "macos-15-intel", python-version: "3.10" }
         exclude:
         - { os: "macos-latest", python-version: "3.10" }
 

.github/workflows/wheels-dependencies.sh

@@ -93,14 +93,18 @@ ARCHIVE_SDIR=pillow-depends-main
 # Package versions for fresh source builds. Version numbers with "Patched"
 # annotations have a source code patch that is required for some platforms. If
 # you change those versions, ensure the patch is also updated.
-FREETYPE_VERSION=2.13.3
-HARFBUZZ_VERSION=11.4.5
+if [[ -n "$IOS_SDK" ]]; then
+  FREETYPE_VERSION=2.13.3
+else
+  FREETYPE_VERSION=2.14.1
+fi
+HARFBUZZ_VERSION=12.1.0
 LIBPNG_VERSION=1.6.50
 JPEGTURBO_VERSION=3.1.2
-OPENJPEG_VERSION=2.5.3
+OPENJPEG_VERSION=2.5.4
 XZ_VERSION=5.8.1
 ZSTD_VERSION=1.5.7
-TIFF_VERSION=4.7.0
+TIFF_VERSION=4.7.1
 LCMS2_VERSION=2.17
 ZLIB_NG_VERSION=2.2.5
 LIBWEBP_VERSION=1.6.0
@@ -267,7 +271,11 @@ function build {
     if [ -z "$IS_ALPINE" ] && [ -z "$SANITIZER" ] && [ -z "$IS_MACOS" ]; then
         yum remove -y zlib-devel
     fi
+    if [[ -n "$IS_MACOS" ]]; then
+        CFLAGS="$CFLAGS -headerpad_max_install_names" build_zlib_ng
+    else
         build_zlib_ng
+    fi
 
     build_simple xcb-proto 1.17.0 https://xorg.freedesktop.org/archive/individual/proto
     if [[ -n "$IS_MACOS" ]]; then
@@ -314,6 +322,10 @@ function build {
 
     if [[ -n "$IS_MACOS" ]]; then
         # Custom freetype build
+        if [[ -z "$IOS_SDK" ]]; then
+          build_simple sed 4.9 https://mirrors.middlendian.com/gnu/sed
+        fi
+
         build_simple freetype $FREETYPE_VERSION https://download.savannah.gnu.org/releases/freetype tar.gz --with-harfbuzz=no
     else
         build_freetype

.github/workflows/wheels.yml

@@ -39,6 +39,7 @@ concurrency:
   cancel-in-progress: true
 
 env:
+  EXPECTED_DISTS: 91
   FORCE_COLOR: 1
 
 jobs:
@@ -52,21 +53,21 @@ jobs:
         include:
           - name: "macOS 10.10 x86_64"
             platform: macos
-            os: macos-13
+            os: macos-15-intel
             cibw_arch: x86_64
-            build: "cp3{9,10,11}*"
+            build: "cp3{10,11}*"
             macosx_deployment_target: "10.10"
           - name: "macOS 10.13 x86_64"
             platform: macos
-            os: macos-13
+            os: macos-15-intel
             cibw_arch: x86_64
-            build: "cp3{12,13,14}*"
+            build: "cp3{12,13}*"
             macosx_deployment_target: "10.13"
           - name: "macOS 10.15 x86_64"
             platform: macos
-            os: macos-13
+            os: macos-15-intel
             cibw_arch: x86_64
-            build: "pp3*"
+            build: "{cp314,pp3}*"
             macosx_deployment_target: "10.15"
           - name: "macOS arm64"
             platform: macos
@@ -99,11 +100,11 @@ jobs:
             cibw_arch: arm64_iphoneos
           - name: "iOS arm64 simulator"
             platform: ios
-            os: macos-14
+            os: macos-latest
             cibw_arch: arm64_iphonesimulator
           - name: "iOS x86_64 simulator"
             platform: ios
-            os: macos-13
+            os: macos-15-intel
             cibw_arch: x86_64_iphonesimulator
     steps:
       - uses: actions/checkout@v5
@@ -231,7 +232,7 @@ jobs:
           path: winbuild\build\bin\fribidi*
 
   sdist:
-    if: github.event_name != 'schedule'
+    if: github.event_name != 'schedule' || github.repository_owner == 'python-pillow'
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v5
@@ -250,15 +251,33 @@ jobs:
         name: dist-sdist
         path: dist/*.tar.gz
 
+  count-dists:
+    needs: [build-native-wheels, windows, sdist]
+    runs-on: ubuntu-latest
+    name: Count dists
+    steps:
+      - uses: actions/download-artifact@v5
+        with:
+          pattern: dist-*
+          path: dist
+          merge-multiple: true
+      - name: "What did we get?"
+        run: |
+          ls -alR
+          echo "Number of dists, should be $EXPECTED_DISTS:"
+          files=$(ls dist 2>/dev/null | wc -l)
+          echo $files
+          [ "$files" -eq $EXPECTED_DISTS ] || exit 1
+
   scientific-python-nightly-wheels-publish:
     if: github.repository_owner == 'python-pillow' && (github.event_name == 'schedule' || github.event_name == 'workflow_dispatch')
-    needs: [build-native-wheels, windows]
+    needs: count-dists
     runs-on: ubuntu-latest
     name: Upload wheels to scientific-python-nightly-wheels
     steps:
       - uses: actions/download-artifact@v5
         with:
-          pattern: dist-*
+          pattern: dist-!(sdist)*
           path: dist
           merge-multiple: true
       - name: Upload wheels to scientific-python-nightly-wheels
@@ -269,7 +288,7 @@ jobs:
 
   pypi-publish:
     if: github.repository_owner == 'python-pillow' && github.event_name == 'push' && startsWith(github.ref, 'refs/tags')
-    needs: [build-native-wheels, windows, sdist]
+    needs: count-dists
     runs-on: ubuntu-latest
     name: Upload release to PyPI
     environment:

.pre-commit-config.yaml

@@ -1,12 +1,12 @@
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.12.11
+    rev: v0.13.3
     hooks:
       - id: ruff-check
         args: [--exit-non-zero-on-fix]
 
   - repo: https://github.com/psf/black-pre-commit-mirror
-    rev: 25.1.0
+    rev: 25.9.0
     hooks:
       - id: black
 
@@ -24,7 +24,7 @@ repos:
         exclude: (Makefile$|\.bat$|\.cmake$|\.eps$|\.fits$|\.gd$|\.opt$|\.patch$)
 
   - repo: https://github.com/pre-commit/mirrors-clang-format
-    rev: v21.1.0
+    rev: v21.1.2
     hooks:
       - id: clang-format
         types: [c]
@@ -51,14 +51,14 @@ repos:
         exclude: ^.github/.*TEMPLATE|^Tests/(fonts|images)/|\.patch$
 
   - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.33.3
+    rev: 0.34.0
     hooks:
       - id: check-github-workflows
       - id: check-readthedocs
       - id: check-renovate
 
   - repo: https://github.com/zizmorcore/zizmor-pre-commit
-    rev: v1.12.1
+    rev: v1.14.2
     hooks:
       - id: zizmor
 
@@ -68,7 +68,7 @@ repos:
       - id: sphinx-lint
 
   - repo: https://github.com/tox-dev/pyproject-fmt
-    rev: v2.6.0
+    rev: v2.7.0
     hooks:
       - id: pyproject-fmt
 

Tests/createfontdatachunk.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python3
 from __future__ import annotations
 
 import base64

Tests/test_arro3.py

@@ -0,0 +1,275 @@
+from __future__ import annotations
+
+import json
+from typing import Any, NamedTuple
+
+import pytest
+
+from PIL import Image
+
+from .helper import (
+    assert_deep_equal,
+    assert_image_equal,
+    hopper,
+    is_big_endian,
+)
+
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from arro3 import compute
+    from arro3.core import (
+        Array,
+        DataType,
+        Field,
+        fixed_size_list_array,
+    )
+else:
+    arro3 = pytest.importorskip("arro3", reason="Arro3 not installed")
+    from arro3 import compute
+    from arro3.core import Array, DataType, Field, fixed_size_list_array
+
+TEST_IMAGE_SIZE = (10, 10)
+
+
+def _test_img_equals_pyarray(
+    img: Image.Image, arr: Any, mask: list[int] | None, elts_per_pixel: int = 1
+) -> None:
+    assert img.height * img.width * elts_per_pixel == len(arr)
+    px = img.load()
+    assert px is not None
+    if elts_per_pixel > 1 and mask is None:
+        # have to do element-wise comparison when we're comparing
+        # flattened r,g,b,a to a pixel.
+        mask = list(range(elts_per_pixel))
+    for x in range(0, img.size[0], int(img.size[0] / 10)):
+        for y in range(0, img.size[1], int(img.size[1] / 10)):
+            if mask:
+                pixel = px[x, y]
+                assert isinstance(pixel, tuple)
+                for ix, elt in enumerate(mask):
+                    if elts_per_pixel == 1:
+                        assert pixel[ix] == arr[y * img.width + x].as_py()[elt]
+                    else:
+                        assert (
+                            pixel[ix]
+                            == arr[(y * img.width + x) * elts_per_pixel + elt].as_py()
+                        )
+            else:
+                assert_deep_equal(px[x, y], arr[y * img.width + x].as_py())
+
+
+def _test_img_equals_int32_pyarray(
+    img: Image.Image, arr: Any, mask: list[int] | None, elts_per_pixel: int = 1
+) -> None:
+    assert img.height * img.width * elts_per_pixel == len(arr)
+    px = img.load()
+    assert px is not None
+    if mask is None:
+        # have to do element-wise comparison when we're comparing
+        # flattened rgba in an uint32 to a pixel.
+        mask = list(range(elts_per_pixel))
+    for x in range(0, img.size[0], int(img.size[0] / 10)):
+        for y in range(0, img.size[1], int(img.size[1] / 10)):
+            pixel = px[x, y]
+            assert isinstance(pixel, tuple)
+            arr_pixel_int = arr[y * img.width + x].as_py()
+            arr_pixel_tuple = (
+                arr_pixel_int % 256,
+                (arr_pixel_int // 256) % 256,
+                (arr_pixel_int // 256**2) % 256,
+                (arr_pixel_int // 256**3),
+            )
+            if is_big_endian():
+                arr_pixel_tuple = arr_pixel_tuple[::-1]
+
+            for ix, elt in enumerate(mask):
+                assert pixel[ix] == arr_pixel_tuple[elt]
+
+
+fl_uint8_4_type = DataType.list(Field("_", DataType.uint8()).with_nullable(False), 4)
+
+
+@pytest.mark.parametrize(
+    "mode, dtype, mask",
+    (
+        ("L", DataType.uint8(), None),
+        ("I", DataType.int32(), None),
+        ("F", DataType.float32(), None),
+        ("LA", fl_uint8_4_type, [0, 3]),
+        ("RGB", fl_uint8_4_type, [0, 1, 2]),
+        ("RGBA", fl_uint8_4_type, None),
+        ("RGBX", fl_uint8_4_type, None),
+        ("CMYK", fl_uint8_4_type, None),
+        ("YCbCr", fl_uint8_4_type, [0, 1, 2]),
+        ("HSV", fl_uint8_4_type, [0, 1, 2]),
+    ),
+)
+def test_to_array(mode: str, dtype: DataType, mask: list[int] | None) -> None:
+    img = hopper(mode)
+
+    # Resize to non-square
+    img = img.crop((3, 0, 124, 127))
+    assert img.size == (121, 127)
+
+    arr = Array(img)
+    _test_img_equals_pyarray(img, arr, mask)
+    assert arr.type == dtype
+
+    reloaded = Image.fromarrow(arr, mode, img.size)
+    assert_image_equal(img, reloaded)
+
+
+def test_lifetime() -> None:
+    # valgrind shouldn't error out here.
+    # arrays should be accessible after the image is deleted.
+
+    img = hopper("L")
+
+    arr_1 = Array(img)
+    arr_2 = Array(img)
+
+    del img
+
+    assert compute.sum(arr_1).as_py() > 0
+    del arr_1
+
+    assert compute.sum(arr_2).as_py() > 0
+    del arr_2
+
+
+def test_lifetime2() -> None:
+    # valgrind shouldn't error out here.
+    # img should remain after the arrays are collected.
+
+    img = hopper("L")
+
+    arr_1 = Array(img)
+    arr_2 = Array(img)
+
+    assert compute.sum(arr_1).as_py() > 0
+    del arr_1
+
+    assert compute.sum(arr_2).as_py() > 0
+    del arr_2
+
+    img2 = img.copy()
+    px = img2.load()
+    assert px  # make mypy happy
+    assert isinstance(px[0, 0], int)
+
+
+class DataShape(NamedTuple):
+    dtype: DataType
+    # Strictly speaking, elt should be a pixel or pixel component, so
+    # list[uint8][4], float, int, uint32, uint8, etc.  But more
+    # correctly, it should be exactly the dtype from the line above.
+    elt: Any
+    elts_per_pixel: int
+
+
+UINT_ARR = DataShape(
+    dtype=fl_uint8_4_type,
+    elt=[1, 2, 3, 4],  # array of 4 uint8 per pixel
+    elts_per_pixel=1,  # only one array per pixel
+)
+
+UINT = DataShape(
+    dtype=DataType.uint8(),
+    elt=3,  # one uint8,
+    elts_per_pixel=4,  # but repeated 4x per pixel
+)
+
+UINT32 = DataShape(
+    dtype=DataType.uint32(),
+    elt=0xABCDEF45,  # one packed int, doesn't fit in a int32 > 0x80000000
+    elts_per_pixel=1,  # one per pixel
+)
+
+INT32 = DataShape(
+    dtype=DataType.uint32(),
+    elt=0x12CDEF45,  # one packed int
+    elts_per_pixel=1,  # one per pixel
+)
+
+
+@pytest.mark.parametrize(
+    "mode, data_tp, mask",
+    (
+        ("L", DataShape(DataType.uint8(), 3, 1), None),
+        ("I", DataShape(DataType.int32(), 1 << 24, 1), None),
+        ("F", DataShape(DataType.float32(), 3.14159, 1), None),
+        ("LA", UINT_ARR, [0, 3]),
+        ("LA", UINT, [0, 3]),
+        ("RGB", UINT_ARR, [0, 1, 2]),
+        ("RGBA", UINT_ARR, None),
+        ("CMYK", UINT_ARR, None),
+        ("YCbCr", UINT_ARR, [0, 1, 2]),
+        ("HSV", UINT_ARR, [0, 1, 2]),
+        ("RGB", UINT, [0, 1, 2]),
+        ("RGBA", UINT, None),
+        ("CMYK", UINT, None),
+        ("YCbCr", UINT, [0, 1, 2]),
+        ("HSV", UINT, [0, 1, 2]),
+    ),
+)
+def test_fromarray(mode: str, data_tp: DataShape, mask: list[int] | None) -> None:
+    (dtype, elt, elts_per_pixel) = data_tp
+
+    ct_pixels = TEST_IMAGE_SIZE[0] * TEST_IMAGE_SIZE[1]
+    if dtype == fl_uint8_4_type:
+        tmp_arr = Array(elt * (ct_pixels * elts_per_pixel), type=DataType.uint8())
+        arr = fixed_size_list_array(tmp_arr, 4)
+    else:
+        arr = Array([elt] * (ct_pixels * elts_per_pixel), type=dtype)
+    img = Image.fromarrow(arr, mode, TEST_IMAGE_SIZE)
+
+    _test_img_equals_pyarray(img, arr, mask, elts_per_pixel)
+
+
+@pytest.mark.parametrize(
+    "mode, mask",
+    (
+        ("LA", [0, 3]),
+        ("RGB", [0, 1, 2]),
+        ("RGBA", None),
+        ("CMYK", None),
+        ("YCbCr", [0, 1, 2]),
+        ("HSV", [0, 1, 2]),
+    ),
+)
+@pytest.mark.parametrize("data_tp", (UINT32, INT32))
+def test_from_int32array(mode: str, mask: list[int] | None, data_tp: DataShape) -> None:
+    (dtype, elt, elts_per_pixel) = data_tp
+
+    ct_pixels = TEST_IMAGE_SIZE[0] * TEST_IMAGE_SIZE[1]
+    arr = Array([elt] * (ct_pixels * elts_per_pixel), type=dtype)
+    img = Image.fromarrow(arr, mode, TEST_IMAGE_SIZE)
+
+    _test_img_equals_int32_pyarray(img, arr, mask, elts_per_pixel)
+
+
+@pytest.mark.parametrize(
+    "mode, metadata",
+    (
+        ("LA", ["L", "X", "X", "A"]),
+        ("RGB", ["R", "G", "B", "X"]),
+        ("RGBX", ["R", "G", "B", "X"]),
+        ("RGBA", ["R", "G", "B", "A"]),
+        ("CMYK", ["C", "M", "Y", "K"]),
+        ("YCbCr", ["Y", "Cb", "Cr", "X"]),
+        ("HSV", ["H", "S", "V", "X"]),
+    ),
+)
+def test_image_metadata(mode: str, metadata: list[str]) -> None:
+    img = hopper(mode)
+
+    arr = Array(img)
+
+    assert arr.type.value_field
+    assert arr.type.value_field.metadata
+    assert arr.type.value_field.metadata[b"image"]
+
+    parsed_metadata = json.loads(arr.type.value_field.metadata[b"image"].decode("utf8"))
+
+    assert "bands" in parsed_metadata
+    assert parsed_metadata["bands"] == metadata

Tests/test_file_avif.py

@@ -14,6 +14,7 @@ import pytest
 
 from PIL import (
     AvifImagePlugin,
+    GifImagePlugin,
     Image,
     ImageDraw,
     ImageFile,
@@ -220,6 +221,7 @@ class TestFileAvif:
     def test_background_from_gif(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/chi.gif") as im:
             original_value = im.convert("RGB").getpixel((1, 1))
+            assert isinstance(original_value, tuple)
 
             # Save as AVIF
             out_avif = tmp_path / "temp.avif"
@@ -232,6 +234,7 @@ class TestFileAvif:
 
         with Image.open(out_gif) as reread:
             reread_value = reread.convert("RGB").getpixel((1, 1))
+        assert isinstance(reread_value, tuple)
         difference = sum([abs(original_value[i] - reread_value[i]) for i in range(3)])
         assert difference <= 6
 
@@ -240,6 +243,7 @@ class TestFileAvif:
         with Image.open("Tests/images/chi.gif") as im:
             im.save(temp_file)
         with Image.open(temp_file) as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 1
 
     def test_invalid_file(self) -> None:
@@ -598,10 +602,12 @@ class TestAvifAnimation:
         """
 
         with Image.open(TEST_AVIF_FILE) as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 1
             assert not im.is_animated
 
         with Image.open("Tests/images/avif/star.avifs") as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 5
             assert im.is_animated
 
@@ -612,11 +618,13 @@ class TestAvifAnimation:
         """
 
         with Image.open("Tests/images/avif/star.gif") as original:
+            assert isinstance(original, GifImagePlugin.GifImageFile)
             assert original.n_frames > 1
 
             temp_file = tmp_path / "temp.avif"
             original.save(temp_file, save_all=True)
             with Image.open(temp_file) as im:
+                assert isinstance(im, AvifImagePlugin.AvifImageFile)
                 assert im.n_frames == original.n_frames
 
                 # Compare first frame in P mode to frame from original GIF
@@ -636,6 +644,7 @@ class TestAvifAnimation:
 
         def check(temp_file: Path) -> None:
             with Image.open(temp_file) as im:
+                assert isinstance(im, AvifImagePlugin.AvifImageFile)
                 assert im.n_frames == 4
 
                 # Compare first frame to original
@@ -708,6 +717,7 @@ class TestAvifAnimation:
             )
 
         with Image.open(temp_file) as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 5
             assert im.is_animated
 
@@ -737,6 +747,7 @@ class TestAvifAnimation:
             )
 
         with Image.open(temp_file) as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 5
             assert im.is_animated
 

Tests/test_file_bmp.py

@@ -6,6 +6,8 @@ from pathlib import Path
 import pytest
 
 from PIL import BmpImagePlugin, Image, _binary
+from PIL._binary import o16le as o16
+from PIL._binary import o32le as o32
 
 from .helper import (
     assert_image_equal,
@@ -114,7 +116,7 @@ def test_save_float_dpi(tmp_path: Path) -> None:
 
 
 def test_load_dib() -> None:
-    # test for #1293, Imagegrab returning Unsupported Bitfields Format
+    # test for #1293, ImageGrab returning Unsupported Bitfields Format
     with Image.open("Tests/images/clipboard.dib") as im:
         assert im.format == "DIB"
         assert im.get_format_mimetype() == "image/bmp"
@@ -219,6 +221,18 @@ def test_rle8_eof(file_name: str, length: int) -> None:
             im.load()
 
 
+def test_unsupported_bmp_bitfields_layout() -> None:
+    fp = io.BytesIO(
+        o32(40)  # header size
+        + b"\x00" * 10
+        + o16(1)  # bits
+        + o32(3)  # BITFIELDS compression
+        + b"\x00" * 32
+    )
+    with pytest.raises(OSError, match="Unsupported BMP bitfields layout"):
+        Image.open(fp)
+
+
 def test_offset() -> None:
     # This image has been hexedited
     # to exclude the palette size from the pixel data offset

Tests/test_file_cur.py

@@ -1,8 +1,13 @@
 from __future__ import annotations
 
+from io import BytesIO
+
 import pytest
 
 from PIL import CurImagePlugin, Image
+from PIL._binary import o8
+from PIL._binary import o16le as o16
+from PIL._binary import o32le as o32
 
 TEST_FILE = "Tests/images/deerstalker.cur"
 
@@ -17,6 +22,24 @@ def test_sanity() -> None:
         assert im.getpixel((16, 16)) == (84, 87, 86, 255)
 
 
+def test_largest_cursor() -> None:
+    magic = b"\x00\x00\x02\x00"
+    sizes = ((1, 1), (8, 8), (4, 4))
+    data = magic + o16(len(sizes))
+    for w, h in sizes:
+        image_offset = 6 + len(sizes) * 16 if (w, h) == max(sizes) else 0
+        data += o8(w) + o8(h) + o8(0) * 10 + o32(image_offset)
+    data += (
+        o32(12)  # header size
+        + o16(8)  # width
+        + o16(16)  # height
+        + o16(0)  # planes
+        + o16(1)  # bits
+    )
+    with Image.open(BytesIO(data)) as im:
+        assert im.size == (8, 8)
+
+
 def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
@@ -26,6 +49,7 @@ def test_invalid_file() -> None:
     no_cursors_file = "Tests/images/no_cursors.cur"
 
     cur = CurImagePlugin.CurImageFile(TEST_FILE)
+    assert cur.fp is not None
     cur.fp.close()
     with open(no_cursors_file, "rb") as cur.fp:
         with pytest.raises(TypeError):

Tests/test_file_eps.py

@@ -197,6 +197,14 @@ def test_load_long_binary_data(prefix: bytes) -> None:
         assert img.format == "EPS"
 
 
+def test_begin_binary() -> None:
+    with open("Tests/images/eps/binary_preview_map.eps", "rb") as fp:
+        data = bytearray(fp.read())
+    data[76875 : 76875 + 11] = b"%" * 11
+    with Image.open(io.BytesIO(data)) as img:
+        assert img.size == (399, 480)
+
+
 @mark_if_feature_version(
     pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
 )

Tests/test_file_fli.py

@@ -48,6 +48,7 @@ def test_sanity() -> None:
 def test_prefix_chunk(monkeypatch: pytest.MonkeyPatch) -> None:
     monkeypatch.setattr(ImageFile, "LOAD_TRUNCATED_IMAGES", True)
     with Image.open(animated_test_file_with_prefix_chunk) as im:
+        assert isinstance(im, FliImagePlugin.FliImageFile)
         assert im.mode == "P"
         assert im.size == (320, 200)
         assert im.format == "FLI"
@@ -55,6 +56,7 @@ def test_prefix_chunk(monkeypatch: pytest.MonkeyPatch) -> None:
         assert im.is_animated
 
         palette = im.getpalette()
+        assert palette is not None
         assert palette[3:6] == [255, 255, 255]
         assert palette[381:384] == [204, 204, 12]
         assert palette[765:] == [252, 0, 0]

Tests/test_file_gd.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from io import BytesIO
+
 import pytest
 
 from PIL import GdImageFile, UnidentifiedImageError
@@ -16,6 +18,14 @@ def test_sanity() -> None:
         assert_image_similar_tofile(im.convert("RGB"), "Tests/images/hopper.jpg", 14)
 
 
+def test_transparency() -> None:
+    with open(TEST_GD_FILE, "rb") as fp:
+        data = bytearray(fp.read())
+    data[7:11] = b"\x00\x00\x00\x05"
+    with GdImageFile.open(BytesIO(data)) as im:
+        assert im.info["transparency"] == 5
+
+
 def test_bad_mode() -> None:
     with pytest.raises(ValueError):
         GdImageFile.open(TEST_GD_FILE, "bad mode")

Tests/test_file_gif.py

@@ -293,6 +293,7 @@ def test_roundtrip_save_all(tmp_path: Path) -> None:
         im.save(out, save_all=True)
 
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
         assert reread.n_frames == 5
 
 
@@ -1374,6 +1375,7 @@ def test_palette_save_all_P(tmp_path: Path) -> None:
 
     with Image.open(out) as im:
         # Assert that the frames are correct, and each frame has the same palette
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert_image_equal(im.convert("RGB"), frames[0].convert("RGB"))
         assert im.palette is not None
         assert im.global_palette is not None

Tests/test_file_jpeg.py

@@ -330,8 +330,10 @@ class TestFileJpeg:
 
         # Reading
         with Image.open("Tests/images/exif_gps.jpg") as im:
-            exif = im._getexif()
-            assert exif[gps_index] == expected_exif_gps
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
+            exif_data = im._getexif()
+            assert exif_data is not None
+            assert exif_data[gps_index] == expected_exif_gps
 
         # Writing
         f = tmp_path / "temp.jpg"
@@ -340,8 +342,10 @@ class TestFileJpeg:
         hopper().save(f, exif=exif)
 
         with Image.open(f) as reloaded:
-            exif = reloaded._getexif()
-            assert exif[gps_index] == expected_exif_gps
+            assert isinstance(reloaded, JpegImagePlugin.JpegImageFile)
+            exif_data = reloaded._getexif()
+            assert exif_data is not None
+            assert exif_data[gps_index] == expected_exif_gps
 
     def test_empty_exif_gps(self) -> None:
         with Image.open("Tests/images/empty_gps_ifd.jpg") as im:
@@ -368,6 +372,7 @@ class TestFileJpeg:
         exifs = []
         for i in range(2):
             with Image.open("Tests/images/exif-200dpcm.jpg") as im:
+                assert isinstance(im, JpegImagePlugin.JpegImageFile)
                 exifs.append(im._getexif())
         assert exifs[0] == exifs[1]
 
@@ -401,13 +406,17 @@ class TestFileJpeg:
         }
 
         with Image.open("Tests/images/exif_gps.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             exif = im._getexif()
+        assert exif is not None
 
         for tag, value in expected_exif.items():
             assert value == exif[tag]
 
     def test_exif_gps_typeerror(self) -> None:
         with Image.open("Tests/images/exif_gps_typeerror.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
+
             # Should not raise a TypeError
             im._getexif()
 
@@ -487,7 +496,9 @@ class TestFileJpeg:
 
     def test_exif(self) -> None:
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             info = im._getexif()
+            assert info is not None
             assert info[305] == "Adobe Photoshop CS Macintosh"
 
     def test_get_child_images(self) -> None:
@@ -690,11 +701,13 @@ class TestFileJpeg:
 
     def test_save_multiple_16bit_qtables(self) -> None:
         with Image.open("Tests/images/hopper_16bit_qtables.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             im2 = self.roundtrip(im, qtables="keep")
             assert im.quantization == im2.quantization
 
     def test_save_single_16bit_qtable(self) -> None:
         with Image.open("Tests/images/hopper_16bit_qtables.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             im2 = self.roundtrip(im, qtables={0: im.quantization[0]})
             assert len(im2.quantization) == 1
             assert im2.quantization[0] == im.quantization[0]
@@ -898,7 +911,10 @@ class TestFileJpeg:
         # in contrast to normal 8
         with Image.open("Tests/images/exif-ifd-offset.jpg") as im:
             # Act / Assert
-            assert im._getexif()[306] == "2017:03:13 23:03:09"
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
+            exif = im._getexif()
+            assert exif is not None
+            assert exif[306] == "2017:03:13 23:03:09"
 
     def test_multiple_exif(self) -> None:
         with Image.open("Tests/images/multiple_exif.jpg") as im:

Tests/test_file_libtiff.py

@@ -355,6 +355,27 @@ class TestFileLibTiff(LibTiffTestCase):
             # Should not segfault
             im.save(outfile)
 
+    def test_whitepoint_tag(
+        self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+    ) -> None:
+        monkeypatch.setattr(TiffImagePlugin, "WRITE_LIBTIFF", True)
+
+        out = tmp_path / "temp.tif"
+        hopper().save(out, tiffinfo={318: (0.3127, 0.3289)})
+
+        with Image.open(out) as reloaded:
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
+            assert reloaded.tag_v2[318] == pytest.approx((0.3127, 0.3289))
+
+        # Save tag by default
+        out = tmp_path / "temp2.tif"
+        with Image.open("Tests/images/rdf.tif") as im:
+            im.save(out)
+
+        with Image.open(out) as reloaded:
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
+            assert reloaded.tag_v2[318] == pytest.approx((0.3127, 0.3289999))
+
     def test_xmlpacket_tag(
         self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
     ) -> None:

Tests/test_file_mpo.py

@@ -104,25 +104,27 @@ def test_exif(test_file: str) -> None:
 
 
 def test_frame_size() -> None:
-    # This image has been hexedited to contain a different size
-    # in the SOF marker of the second frame
-    with Image.open("Tests/images/sugarshack_frame_size.mpo") as im:
-        assert im.size == (640, 480)
+    with Image.open("Tests/images/frame_size.mpo") as im:
+        assert im.size == (56, 70)
+        im.load()
 
         im.seek(1)
-        assert im.size == (680, 480)
+        assert im.size == (349, 434)
+        im.load()
 
         im.seek(0)
-        assert im.size == (640, 480)
+        assert im.size == (56, 70)
 
 
 def test_ignore_frame_size() -> None:
     # Ignore the different size of the second frame
     # since this is not a "Large Thumbnail" image
     with Image.open("Tests/images/ignore_frame_size.mpo") as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         assert im.size == (64, 64)
 
         im.seek(1)
+        assert im.mpinfo is not None
         assert (
             im.mpinfo[0xB002][1]["Attribute"]["MPType"]
             == "Multi-Frame Image: (Disparity)"
@@ -155,6 +157,7 @@ def test_reload_exif_after_seek() -> None:
 @pytest.mark.parametrize("test_file", test_files)
 def test_mp(test_file: str) -> None:
     with Image.open(test_file) as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         mpinfo = im._getmp()
         assert mpinfo is not None
         assert mpinfo[45056] == b"0100"
@@ -165,6 +168,7 @@ def test_mp_offset() -> None:
     # This image has been manually hexedited to have an IFD offset of 10
     # in APP2 data, in contrast to normal 8
     with Image.open("Tests/images/sugarshack_ifd_offset.mpo") as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         mpinfo = im._getmp()
         assert mpinfo is not None
         assert mpinfo[45056] == b"0100"
@@ -182,6 +186,7 @@ def test_mp_no_data() -> None:
 @pytest.mark.parametrize("test_file", test_files)
 def test_mp_attribute(test_file: str) -> None:
     with Image.open(test_file) as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         mpinfo = im._getmp()
     assert mpinfo is not None
     for frame_number, mpentry in enumerate(mpinfo[0xB002]):

Tests/test_file_pcd.py

@@ -6,6 +6,8 @@ import pytest
 
 from PIL import Image
 
+from .helper import assert_image_equal
+
 
 def test_load_raw() -> None:
     with Image.open("Tests/images/hopper.pcd") as im:
@@ -30,3 +32,8 @@ def test_rotated(orientation: int) -> None:
     f = BytesIO(data)
     with Image.open(f) as im:
         assert im.size == (512, 768)
+
+        with Image.open("Tests/images/hopper.pcd") as expected:
+            assert_image_equal(
+                im, expected.rotate(90 if orientation == 1 else 270, expand=True)
+            )

Tests/test_file_png.py

@@ -229,7 +229,9 @@ class TestFilePng:
         assert_image(im, "RGBA", (162, 150))
 
         # image has 124 unique alpha values
-        assert len(im.getchannel("A").getcolors()) == 124
+        colors = im.getchannel("A").getcolors()
+        assert colors is not None
+        assert len(colors) == 124
 
     def test_load_transparent_rgb(self) -> None:
         test_file = "Tests/images/rgb_trns.png"
@@ -241,7 +243,9 @@ class TestFilePng:
         assert_image(im, "RGBA", (64, 64))
 
         # image has 876 transparent pixels
-        assert im.getchannel("A").getcolors()[0][0] == 876
+        colors = im.getchannel("A").getcolors()
+        assert colors is not None
+        assert colors[0][0] == 876
 
     def test_save_p_transparent_palette(self, tmp_path: Path) -> None:
         in_file = "Tests/images/pil123p.png"
@@ -262,7 +266,9 @@ class TestFilePng:
         assert_image(im, "RGBA", (162, 150))
 
         # image has 124 unique alpha values
-        assert len(im.getchannel("A").getcolors()) == 124
+        colors = im.getchannel("A").getcolors()
+        assert colors is not None
+        assert len(colors) == 124
 
     def test_save_p_single_transparency(self, tmp_path: Path) -> None:
         in_file = "Tests/images/p_trns_single.png"
@@ -285,7 +291,9 @@ class TestFilePng:
         assert im.getpixel((31, 31)) == (0, 255, 52, 0)
 
         # image has 876 transparent pixels
-        assert im.getchannel("A").getcolors()[0][0] == 876
+        colors = im.getchannel("A").getcolors()
+        assert colors is not None
+        assert colors[0][0] == 876
 
     def test_save_p_transparent_black(self, tmp_path: Path) -> None:
         # check if solid black image with full transparency
@@ -313,7 +321,9 @@ class TestFilePng:
                 assert im.info["transparency"] == 255
 
                 im_rgba = im.convert("RGBA")
-            assert im_rgba.getchannel("A").getcolors()[0][0] == num_transparent
+            colors = im_rgba.getchannel("A").getcolors()
+            assert colors is not None
+            assert colors[0][0] == num_transparent
 
             test_file = tmp_path / "temp.png"
             im.save(test_file)
@@ -324,7 +334,9 @@ class TestFilePng:
                 assert_image_equal(im, test_im)
 
             test_im_rgba = test_im.convert("RGBA")
-            assert test_im_rgba.getchannel("A").getcolors()[0][0] == num_transparent
+            colors = test_im_rgba.getchannel("A").getcolors()
+            assert colors is not None
+            assert colors[0][0] == num_transparent
 
     def test_save_rgb_single_transparency(self, tmp_path: Path) -> None:
         in_file = "Tests/images/caption_6_33_22.png"
@@ -671,6 +683,9 @@ class TestFilePng:
         im.save(out, bits=4, save_all=save_all)
 
         with Image.open(out) as reloaded:
+            assert isinstance(reloaded, PngImagePlugin.PngImageFile)
+            assert reloaded.png is not None
+            assert reloaded.png.im_palette is not None
             assert len(reloaded.png.im_palette[1]) == 48
 
     def test_plte_length(self, tmp_path: Path) -> None:
@@ -681,6 +696,9 @@ class TestFilePng:
         im.save(out)
 
         with Image.open(out) as reloaded:
+            assert isinstance(reloaded, PngImagePlugin.PngImageFile)
+            assert reloaded.png is not None
+            assert reloaded.png.im_palette is not None
             assert len(reloaded.png.im_palette[1]) == 3
 
     def test_getxmp(self) -> None:
@@ -702,13 +720,17 @@ class TestFilePng:
     def test_exif(self) -> None:
         # With an EXIF chunk
         with Image.open("Tests/images/exif.png") as im:
-            exif = im._getexif()
-        assert exif[274] == 1
+            assert isinstance(im, PngImagePlugin.PngImageFile)
+            exif_data = im._getexif()
+        assert exif_data is not None
+        assert exif_data[274] == 1
 
         # With an ImageMagick zTXt chunk
         with Image.open("Tests/images/exif_imagemagick.png") as im:
-            exif = im._getexif()
-            assert exif[274] == 1
+            assert isinstance(im, PngImagePlugin.PngImageFile)
+            exif_data = im._getexif()
+            assert exif_data is not None
+            assert exif_data[274] == 1
 
             # Assert that info still can be extracted
             # when the image is no longer a PngImageFile instance
@@ -717,8 +739,10 @@ class TestFilePng:
 
         # With a tEXt chunk
         with Image.open("Tests/images/exif_text.png") as im:
-            exif = im._getexif()
-        assert exif[274] == 1
+            assert isinstance(im, PngImagePlugin.PngImageFile)
+            exif_data = im._getexif()
+        assert exif_data is not None
+        assert exif_data[274] == 1
 
         # With XMP tags
         with Image.open("Tests/images/xmp_tags_orientation.png") as im:
@@ -740,8 +764,10 @@ class TestFilePng:
             im.save(test_file, exif=im.getexif())
 
         with Image.open(test_file) as reloaded:
-            exif = reloaded._getexif()
-        assert exif[274] == 1
+            assert isinstance(reloaded, PngImagePlugin.PngImageFile)
+            exif_data = reloaded._getexif()
+        assert exif_data is not None
+        assert exif_data[274] == 1
 
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"

Tests/test_file_ppm.py

@@ -92,6 +92,13 @@ def test_16bit_pgm() -> None:
         assert_image_equal_tofile(im, "Tests/images/16_bit_binary_pgm.tiff")
 
 
+def test_p4_save(tmp_path: Path) -> None:
+    with Image.open("Tests/images/hopper_1bit.pbm") as im:
+        filename = tmp_path / "temp.pbm"
+        im.save(filename)
+        assert_image_equal_tofile(im, filename)
+
+
 def test_16bit_pgm_write(tmp_path: Path) -> None:
     with Image.open("Tests/images/16_bit_binary.pgm") as im:
         filename = tmp_path / "temp.pgm"
@@ -134,6 +141,12 @@ def test_pfm_big_endian(tmp_path: Path) -> None:
         assert_image_equal_tofile(im, filename)
 
 
+def test_save_unsupported_mode(tmp_path: Path) -> None:
+    im = hopper("P")
+    with pytest.raises(OSError, match="cannot write mode P as PPM"):
+        im.save(tmp_path / "out.ppm")
+
+
 @pytest.mark.parametrize(
     "data",
     [

Tests/test_file_tga.py

@@ -274,13 +274,17 @@ def test_save_l_transparency(tmp_path: Path) -> None:
     in_file = "Tests/images/la.tga"
     with Image.open(in_file) as im:
         assert im.mode == "LA"
-        assert im.getchannel("A").getcolors()[0][0] == num_transparent
+        colors = im.getchannel("A").getcolors()
+        assert colors is not None
+        assert colors[0][0] == num_transparent
 
         out = tmp_path / "temp.tga"
         im.save(out)
 
     with Image.open(out) as test_im:
         assert test_im.mode == "LA"
-        assert test_im.getchannel("A").getcolors()[0][0] == num_transparent
+        colors = test_im.getchannel("A").getcolors()
+        assert colors is not None
+        assert colors[0][0] == num_transparent
 
         assert_image_equal(im, test_im)

Tests/test_file_webp_metadata.py

@@ -22,11 +22,13 @@ except ImportError:
 def test_read_exif_metadata() -> None:
     file_path = "Tests/images/flower.webp"
     with Image.open(file_path) as image:
+        assert isinstance(image, WebPImagePlugin.WebPImageFile)
         assert image.format == "WEBP"
         exif_data = image.info.get("exif", None)
         assert exif_data
 
         exif = image._getexif()
+        assert exif is not None
 
         # Camera make
         assert exif[271] == "Canon"

Tests/test_image.py

@@ -284,33 +284,6 @@ class TestImage:
         assert item is not None
         assert item != num
 
-    def test_expand_x(self) -> None:
-        # Arrange
-        im = hopper()
-        orig_size = im.size
-        xmargin = 5
-
-        # Act
-        im = im._expand(xmargin)
-
-        # Assert
-        assert im.size[0] == orig_size[0] + 2 * xmargin
-        assert im.size[1] == orig_size[1] + 2 * xmargin
-
-    def test_expand_xy(self) -> None:
-        # Arrange
-        im = hopper()
-        orig_size = im.size
-        xmargin = 5
-        ymargin = 3
-
-        # Act
-        im = im._expand(xmargin, ymargin)
-
-        # Assert
-        assert im.size[0] == orig_size[0] + 2 * xmargin
-        assert im.size[1] == orig_size[1] + 2 * ymargin
-
     def test_getbands(self) -> None:
         # Assert
         assert hopper("RGB").getbands() == ("R", "G", "B")
@@ -1126,6 +1099,12 @@ class TestImage:
             assert im.palette is not None
             assert im.palette.colors[(27, 35, 6, 214)] == 24
 
+    def test_merge_pa(self) -> None:
+        p = hopper("P")
+        a = Image.new("L", p.size)
+        pa = Image.merge("PA", (p, a))
+        assert p.getpalette() == pa.getpalette()
+
     def test_constants(self) -> None:
         for enum in (
             Image.Transpose,

Tests/test_image_convert.py

@@ -97,6 +97,13 @@ def test_opaque() -> None:
     assert_image_equal(alpha, solid)
 
 
+def test_rgba() -> None:
+    with Image.open("Tests/images/transparent.png") as im:
+        assert im.mode == "RGBA"
+
+        assert_image_similar(im.convert("RGBa").convert("RGB"), im.convert("RGB"), 1.5)
+
+
 def test_rgba_p() -> None:
     im = hopper("RGBA")
     im.putalpha(hopper("L"))
@@ -107,11 +114,19 @@ def test_rgba_p() -> None:
     assert_image_similar(im, comparable, 20)
 
 
-def test_rgba() -> None:
-    with Image.open("Tests/images/transparent.png") as im:
-        assert im.mode == "RGBA"
+def test_rgba_pa() -> None:
+    im = hopper("RGBA").convert("PA").convert("RGB")
+    expected = hopper("RGB")
 
-        assert_image_similar(im.convert("RGBa").convert("RGB"), im.convert("RGB"), 1.5)
+    assert_image_similar(im, expected, 9.3)
+
+
+def test_pa() -> None:
+    im = hopper().convert("PA")
+
+    palette = im.palette
+    assert palette is not None
+    assert palette.colors != {}
 
 
 def test_trns_p(tmp_path: Path) -> None:

Tests/test_image_paste.py

@@ -124,6 +124,21 @@ class TestImagingPaste:
         im = im.crop((12, 23, im2.width + 12, im2.height + 23))
         assert_image_equal(im, im2)
 
+    @pytest.mark.parametrize("y", [10, -10])
+    @pytest.mark.parametrize("mode", ["L", "RGB"])
+    @pytest.mark.parametrize("mask_mode", ["", "1", "L", "LA", "RGBa"])
+    def test_image_self(self, y: int, mode: str, mask_mode: str) -> None:
+        im = getattr(self, "gradient_" + mode)
+        mask = Image.new(mask_mode, im.size, 0xFFFFFFFF) if mask_mode else None
+
+        im_self = im.copy()
+        im_self.paste(im_self, (0, y), mask)
+
+        im_copy = im.copy()
+        im_copy.paste(im_copy.copy(), (0, y), mask)
+
+        assert_image_equal(im_self, im_copy)
+
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
     def test_image_mask_1(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")

Tests/test_image_putpalette.py

@@ -62,6 +62,7 @@ def test_putpalette_with_alpha_values() -> None:
         expected = im.convert("RGBA")
 
         palette = im.getpalette()
+        assert palette is not None
         transparency = im.info.pop("transparency")
 
         palette_with_alpha_values = []

Tests/test_image_quantize.py

@@ -118,6 +118,15 @@ def test_quantize_kmeans(method: Image.Quantize) -> None:
         im.quantize(kmeans=-1, method=method)
 
 
+@skip_unless_feature("libimagequant")
+def test_resize() -> None:
+    im = hopper().resize((100, 100))
+    converted = im.quantize(100, Image.Quantize.LIBIMAGEQUANT)
+    colors = converted.getcolors()
+    assert colors is not None
+    assert len(colors) == 100
+
+
 def test_colors() -> None:
     im = hopper()
     colors = 2

Tests/test_imagedraw.py

@@ -1494,7 +1494,9 @@ def test_default_font_size() -> None:
 
     def draw_text() -> None:
         draw.text((0, 0), text, font_size=16)
-        assert_image_equal_tofile(im, "Tests/images/imagedraw_default_font_size.png")
+        assert_image_similar_tofile(
+            im, "Tests/images/imagedraw_default_font_size.png", 1
+        )
 
     check(draw_text)
 
@@ -1513,7 +1515,9 @@ def test_default_font_size() -> None:
 
     def draw_multiline_text() -> None:
         draw.multiline_text((0, 0), text, font_size=16)
-        assert_image_equal_tofile(im, "Tests/images/imagedraw_default_font_size.png")
+        assert_image_similar_tofile(
+            im, "Tests/images/imagedraw_default_font_size.png", 1
+        )
 
     check(draw_multiline_text)
 

Tests/test_imagefile.py

@@ -164,6 +164,11 @@ class TestImageFile:
         with pytest.raises(OSError):
             p.close()
 
+    def test_negative_offset(self) -> None:
+        with Image.open("Tests/images/raw_negative_stride.bin") as im:
+            with pytest.raises(ValueError, match="Tile offset cannot be negative"):
+                im.load()
+
     def test_no_format(self) -> None:
         buf = BytesIO(b"\x00" * 255)
 

Tests/test_imagefont.py

@@ -19,6 +19,7 @@ from .helper import (
     assert_image_equal,
     assert_image_equal_tofile,
     assert_image_similar_tofile,
+    has_feature_version,
     is_win32,
     skip_unless_feature,
     skip_unless_feature_version,
@@ -492,6 +493,11 @@ def test_stroke_mask() -> None:
     assert mask.getpixel((42, 5)) == 255
 
 
+def test_load_invalid_file() -> None:
+    with pytest.raises(SyntaxError, match="Not a PILfont file"):
+        ImageFont.load("Tests/images/1_trns.png")
+
+
 def test_load_when_image_not_found() -> None:
     with tempfile.NamedTemporaryFile(delete=False) as tmp:
         pass
@@ -549,7 +555,7 @@ def test_default_font() -> None:
     draw.text((10, 60), txt, font=larger_default_font)
 
     # Assert
-    assert_image_equal_tofile(im, "Tests/images/default_font_freetype.png")
+    assert_image_similar_tofile(im, "Tests/images/default_font_freetype.png", 0.13)
 
 
 @pytest.mark.parametrize("mode", ("", "1", "RGBA"))
@@ -1055,7 +1061,10 @@ def test_colr(layout_engine: ImageFont.Layout) -> None:
 
     d.text((15, 5), "Bungee", font=font, embedded_color=True)
 
-    assert_image_similar_tofile(im, "Tests/images/colr_bungee.png", 21)
+    if has_feature_version("freetype2", "2.14.0"):
+        assert_image_similar_tofile(im, "Tests/images/colr_bungee.png", 6.1)
+    else:
+        assert_image_similar_tofile(im, "Tests/images/colr_bungee_older.png", 21)
 
 
 @skip_unless_feature_version("freetype2", "2.10.0")
@@ -1071,7 +1080,7 @@ def test_colr_mask(layout_engine: ImageFont.Layout) -> None:
 
     d.text((15, 5), "Bungee", "black", font=font)
 
-    assert_image_similar_tofile(im, "Tests/images/colr_bungee_mask.png", 22)
+    assert_image_similar_tofile(im, "Tests/images/colr_bungee_mask.png", 14.1)
 
 
 def test_woff2(layout_engine: ImageFont.Layout) -> None:

Tests/test_imagefontctl.py

@@ -183,7 +183,7 @@ def test_x_max_and_y_offset() -> None:
     draw.text((0, 0), "لح", font=ttf, fill=500)
 
     target = "Tests/images/test_x_max_and_y_offset.png"
-    assert_image_similar_tofile(im, target, 0.5)
+    assert_image_similar_tofile(im, target, 3.8)
 
 
 def test_language() -> None:

Tests/test_imagefontpil.py

@@ -30,6 +30,14 @@ def test_default_font(font: ImageFont.ImageFont) -> None:
     assert_image_equal_tofile(im, "Tests/images/default_font.png")
 
 
+def test_invalid_mode() -> None:
+    font = ImageFont.ImageFont()
+    fp = BytesIO()
+    with Image.open("Tests/images/hopper.png") as im:
+        with pytest.raises(TypeError, match="invalid font image mode"):
+            font._load_pilfont_data(fp, im)
+
+
 def test_without_freetype() -> None:
     original_core = ImageFont.core
     if features.check_module("freetype2"):

Tests/test_imageops.py

@@ -186,6 +186,21 @@ def test_palette(mode: str) -> None:
     )
 
 
+def test_rgba_palette() -> None:
+    im = Image.new("P", (1, 1))
+
+    red = (255, 0, 0, 255)
+    translucent_black = (0, 0, 0, 127)
+    im.putpalette(red + translucent_black, "RGBA")
+
+    expanded_im = ImageOps.expand(im, 1, 1)
+
+    palette = expanded_im.palette
+    assert palette is not None
+    assert palette.mode == "RGBA"
+    assert expanded_im.convert("RGBA").getpixel((0, 0)) == translucent_black
+
+
 def test_pil163() -> None:
     # Division by zero in equalize if < 255 pixels in image (@PIL163)
 

Tests/test_imagesequence.py

@@ -76,9 +76,14 @@ def test_consecutive() -> None:
 def test_palette_mmap() -> None:
     # Using mmap in ImageFile can require to reload the palette.
     with Image.open("Tests/images/multipage-mmap.tiff") as im:
-        color1 = im.getpalette()[:3]
+        palette = im.getpalette()
+        assert palette is not None
+        color1 = palette[:3]
         im.seek(0)
-        color2 = im.getpalette()[:3]
+
+        palette = im.getpalette()
+        assert palette is not None
+        color2 = palette[:3]
         assert color1 == color2
 
 

Tests/test_imagetext.py

@@ -0,0 +1,72 @@
+from __future__ import annotations
+
+import pytest
+
+from PIL import Image, ImageDraw, ImageFont, ImageText
+
+from .helper import assert_image_similar_tofile, skip_unless_feature
+
+FONT_PATH = "Tests/fonts/FreeMono.ttf"
+
+
+@pytest.fixture(
+    scope="module",
+    params=[
+        pytest.param(ImageFont.Layout.BASIC),
+        pytest.param(ImageFont.Layout.RAQM, marks=skip_unless_feature("raqm")),
+    ],
+)
+def layout_engine(request: pytest.FixtureRequest) -> ImageFont.Layout:
+    return request.param
+
+
+@pytest.fixture(scope="module")
+def font(layout_engine: ImageFont.Layout) -> ImageFont.FreeTypeFont:
+    return ImageFont.truetype(FONT_PATH, 20, layout_engine=layout_engine)
+
+
+def test_get_length(font: ImageFont.FreeTypeFont) -> None:
+    assert ImageText.Text("A", font).get_length() == 12
+    assert ImageText.Text("AB", font).get_length() == 24
+    assert ImageText.Text("M", font).get_length() == 12
+    assert ImageText.Text("y", font).get_length() == 12
+    assert ImageText.Text("a", font).get_length() == 12
+
+
+def test_get_bbox(font: ImageFont.FreeTypeFont) -> None:
+    assert ImageText.Text("A", font).get_bbox() == (0, 4, 12, 16)
+    assert ImageText.Text("AB", font).get_bbox() == (0, 4, 24, 16)
+    assert ImageText.Text("M", font).get_bbox() == (0, 4, 12, 16)
+    assert ImageText.Text("y", font).get_bbox() == (0, 7, 12, 20)
+    assert ImageText.Text("a", font).get_bbox() == (0, 7, 12, 16)
+
+
+def test_standard_embedded_color(layout_engine: ImageFont.Layout) -> None:
+    font = ImageFont.truetype(FONT_PATH, 40, layout_engine=layout_engine)
+    text = ImageText.Text("Hello World!", font)
+    text.embed_color()
+
+    im = Image.new("RGB", (300, 64), "white")
+    draw = ImageDraw.Draw(im)
+    draw.text((10, 10), text, "#fa6")
+
+    assert_image_similar_tofile(im, "Tests/images/standard_embedded.png", 3.1)
+
+
+@skip_unless_feature("freetype2")
+def test_stroke() -> None:
+    for suffix, stroke_fill in {"same": None, "different": "#0f0"}.items():
+        # Arrange
+        im = Image.new("RGB", (120, 130))
+        draw = ImageDraw.Draw(im)
+        font = ImageFont.truetype(FONT_PATH, 120)
+        text = ImageText.Text("A", font)
+        text.stroke(2, stroke_fill)
+
+        # Act
+        draw.text((12, 12), text, "#f00")
+
+        # Assert
+        assert_image_similar_tofile(
+            im, "Tests/images/imagedraw_stroke_" + suffix + ".png", 3.1
+        )

Tests/test_nanoarrow.py

@@ -0,0 +1,302 @@
+from __future__ import annotations
+
+import json
+from typing import Any, NamedTuple
+
+import pytest
+
+from PIL import Image
+
+from .helper import (
+    assert_deep_equal,
+    assert_image_equal,
+    hopper,
+    is_big_endian,
+)
+
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    import nanoarrow  # type: ignore [import-not-found]
+else:
+    nanoarrow = pytest.importorskip("nanoarrow", reason="Nanoarrow not installed")
+
+TEST_IMAGE_SIZE = (10, 10)
+
+
+def _test_img_equals_pyarray(
+    img: Image.Image, arr: Any, mask: list[int] | None, elts_per_pixel: int = 1
+) -> None:
+    assert img.height * img.width * elts_per_pixel == len(arr)
+    px = img.load()
+    assert px is not None
+    if elts_per_pixel > 1 and mask is None:
+        # have to do element-wise comparison when we're comparing
+        # flattened r,g,b,a to a pixel.
+        mask = list(range(elts_per_pixel))
+    for x in range(0, img.size[0], int(img.size[0] / 10)):
+        for y in range(0, img.size[1], int(img.size[1] / 10)):
+            if mask:
+                pixel = px[x, y]
+                assert isinstance(pixel, tuple)
+                for ix, elt in enumerate(mask):
+                    if elts_per_pixel == 1:
+                        assert pixel[ix] == arr[y * img.width + x].as_py()[elt]
+                    else:
+                        assert (
+                            pixel[ix]
+                            == arr[(y * img.width + x) * elts_per_pixel + elt].as_py()
+                        )
+            else:
+                assert_deep_equal(px[x, y], arr[y * img.width + x].as_py())
+
+
+def _test_img_equals_int32_pyarray(
+    img: Image.Image, arr: Any, mask: list[int] | None, elts_per_pixel: int = 1
+) -> None:
+    assert img.height * img.width * elts_per_pixel == len(arr)
+    px = img.load()
+    assert px is not None
+    if mask is None:
+        # have to do element-wise comparison when we're comparing
+        # flattened rgba in an uint32 to a pixel.
+        mask = list(range(elts_per_pixel))
+    for x in range(0, img.size[0], int(img.size[0] / 10)):
+        for y in range(0, img.size[1], int(img.size[1] / 10)):
+            pixel = px[x, y]
+            assert isinstance(pixel, tuple)
+            arr_pixel_int = arr[y * img.width + x].as_py()
+            arr_pixel_tuple = (
+                arr_pixel_int % 256,
+                (arr_pixel_int // 256) % 256,
+                (arr_pixel_int // 256**2) % 256,
+                (arr_pixel_int // 256**3),
+            )
+            if is_big_endian():
+                arr_pixel_tuple = arr_pixel_tuple[::-1]
+
+            for ix, elt in enumerate(mask):
+                assert pixel[ix] == arr_pixel_tuple[elt]
+
+
+fl_uint8_4_type = nanoarrow.fixed_size_list(
+    value_type=nanoarrow.uint8(nullable=False), list_size=4, nullable=False
+)
+
+
+@pytest.mark.parametrize(
+    "mode, dtype, mask",
+    (
+        ("L", nanoarrow.uint8(nullable=False), None),
+        ("I", nanoarrow.int32(nullable=False), None),
+        ("F", nanoarrow.float32(nullable=False), None),
+        ("LA", fl_uint8_4_type, [0, 3]),
+        ("RGB", fl_uint8_4_type, [0, 1, 2]),
+        ("RGBA", fl_uint8_4_type, None),
+        ("RGBX", fl_uint8_4_type, None),
+        ("CMYK", fl_uint8_4_type, None),
+        ("YCbCr", fl_uint8_4_type, [0, 1, 2]),
+        ("HSV", fl_uint8_4_type, [0, 1, 2]),
+    ),
+)
+def test_to_array(mode: str, dtype: nanoarrow, mask: list[int] | None) -> None:
+    img = hopper(mode)
+
+    # Resize to non-square
+    img = img.crop((3, 0, 124, 127))
+    assert img.size == (121, 127)
+
+    arr = nanoarrow.Array(img)
+    _test_img_equals_pyarray(img, arr, mask)
+    assert arr.schema.type == dtype.type
+    assert arr.schema.nullable == dtype.nullable
+
+    reloaded = Image.fromarrow(arr, mode, img.size)
+    assert_image_equal(img, reloaded)
+
+
+def test_lifetime() -> None:
+    # valgrind shouldn't error out here.
+    # arrays should be accessible after the image is deleted.
+
+    img = hopper("L")
+
+    arr_1 = nanoarrow.Array(img)
+    arr_2 = nanoarrow.Array(img)
+
+    del img
+
+    assert sum(arr_1.iter_py()) > 0
+    del arr_1
+
+    assert sum(arr_2.iter_py()) > 0
+    del arr_2
+
+
+def test_lifetime2() -> None:
+    # valgrind shouldn't error out here.
+    # img should remain after the arrays are collected.
+
+    img = hopper("L")
+
+    arr_1 = nanoarrow.Array(img)
+    arr_2 = nanoarrow.Array(img)
+
+    assert sum(arr_1.iter_py()) > 0
+    del arr_1
+
+    assert sum(arr_2.iter_py()) > 0
+    del arr_2
+
+    img2 = img.copy()
+    px = img2.load()
+    assert px  # make mypy happy
+    assert isinstance(px[0, 0], int)
+
+
+class DataShape(NamedTuple):
+    dtype: nanoarrow
+    # Strictly speaking, elt should be a pixel or pixel component, so
+    # list[uint8][4], float, int, uint32, uint8, etc.  But more
+    # correctly, it should be exactly the dtype from the line above.
+    elt: Any
+    elts_per_pixel: int
+
+
+UINT_ARR = DataShape(
+    dtype=fl_uint8_4_type,
+    elt=[1, 2, 3, 4],  # array of 4 uint8 per pixel
+    elts_per_pixel=1,  # only one array per pixel
+)
+
+UINT = DataShape(
+    dtype=nanoarrow.uint8(),
+    elt=3,  # one uint8,
+    elts_per_pixel=4,  # but repeated 4x per pixel
+)
+
+UINT32 = DataShape(
+    dtype=nanoarrow.uint32(),
+    elt=0xABCDEF45,  # one packed int, doesn't fit in a int32 > 0x80000000
+    elts_per_pixel=1,  # one per pixel
+)
+
+INT32 = DataShape(
+    dtype=nanoarrow.uint32(),
+    elt=0x12CDEF45,  # one packed int
+    elts_per_pixel=1,  # one per pixel
+)
+
+
+@pytest.mark.parametrize(
+    "mode, data_tp, mask",
+    (
+        ("L", DataShape(nanoarrow.uint8(), 3, 1), None),
+        ("I", DataShape(nanoarrow.int32(), 1 << 24, 1), None),
+        ("F", DataShape(nanoarrow.float32(), 3.14159, 1), None),
+        ("LA", UINT_ARR, [0, 3]),
+        ("LA", UINT, [0, 3]),
+        ("RGB", UINT_ARR, [0, 1, 2]),
+        ("RGBA", UINT_ARR, None),
+        ("CMYK", UINT_ARR, None),
+        ("YCbCr", UINT_ARR, [0, 1, 2]),
+        ("HSV", UINT_ARR, [0, 1, 2]),
+        ("RGB", UINT, [0, 1, 2]),
+        ("RGBA", UINT, None),
+        ("CMYK", UINT, None),
+        ("YCbCr", UINT, [0, 1, 2]),
+        ("HSV", UINT, [0, 1, 2]),
+    ),
+)
+def test_fromarray(mode: str, data_tp: DataShape, mask: list[int] | None) -> None:
+    (dtype, elt, elts_per_pixel) = data_tp
+
+    ct_pixels = TEST_IMAGE_SIZE[0] * TEST_IMAGE_SIZE[1]
+    if dtype == fl_uint8_4_type:
+        tmp_arr = nanoarrow.Array(
+            elt * (ct_pixels * elts_per_pixel), schema=nanoarrow.uint8()
+        )
+        c_array = nanoarrow.c_array_from_buffers(
+            dtype, ct_pixels, buffers=[], children=[tmp_arr]
+        )
+        arr = nanoarrow.Array(c_array)
+    else:
+        arr = nanoarrow.Array(
+            nanoarrow.c_array([elt] * (ct_pixels * elts_per_pixel), schema=dtype)
+        )
+    img = Image.fromarrow(arr, mode, TEST_IMAGE_SIZE)
+
+    _test_img_equals_pyarray(img, arr, mask, elts_per_pixel)
+
+
+@pytest.mark.parametrize(
+    "mode, mask",
+    (
+        ("LA", [0, 3]),
+        ("RGB", [0, 1, 2]),
+        ("RGBA", None),
+        ("CMYK", None),
+        ("YCbCr", [0, 1, 2]),
+        ("HSV", [0, 1, 2]),
+    ),
+)
+@pytest.mark.parametrize("data_tp", (UINT32, INT32))
+def test_from_int32array(mode: str, mask: list[int] | None, data_tp: DataShape) -> None:
+    (dtype, elt, elts_per_pixel) = data_tp
+
+    ct_pixels = TEST_IMAGE_SIZE[0] * TEST_IMAGE_SIZE[1]
+    arr = nanoarrow.Array(
+        nanoarrow.c_array([elt] * (ct_pixels * elts_per_pixel), schema=dtype)
+    )
+    img = Image.fromarrow(arr, mode, TEST_IMAGE_SIZE)
+
+    _test_img_equals_int32_pyarray(img, arr, mask, elts_per_pixel)
+
+
+@pytest.mark.parametrize(
+    "mode, metadata",
+    (
+        ("LA", ["L", "X", "X", "A"]),
+        ("RGB", ["R", "G", "B", "X"]),
+        ("RGBX", ["R", "G", "B", "X"]),
+        ("RGBA", ["R", "G", "B", "A"]),
+        ("CMYK", ["C", "M", "Y", "K"]),
+        ("YCbCr", ["Y", "Cb", "Cr", "X"]),
+        ("HSV", ["H", "S", "V", "X"]),
+    ),
+)
+def test_image_nested_metadata(mode: str, metadata: list[str]) -> None:
+    img = hopper(mode)
+
+    arr = nanoarrow.Array(img)
+
+    assert arr.schema.value_type.metadata
+    assert arr.schema.value_type.metadata[b"image"]
+
+    parsed_metadata = json.loads(
+        arr.schema.value_type.metadata[b"image"].decode("utf8")
+    )
+
+    assert "bands" in parsed_metadata
+    assert parsed_metadata["bands"] == metadata
+
+
+@pytest.mark.parametrize(
+    "mode, metadata",
+    (
+        ("L", ["L"]),
+        ("I", ["I"]),
+        ("F", ["F"]),
+    ),
+)
+def test_image_flat_metadata(mode: str, metadata: list[str]) -> None:
+    img = hopper(mode)
+
+    arr = nanoarrow.Array(img)
+
+    assert arr.schema.metadata
+    assert arr.schema.metadata[b"image"]
+
+    parsed_metadata = json.loads(arr.schema.metadata[b"image"].decode("utf8"))
+
+    assert "bands" in parsed_metadata
+    assert parsed_metadata["bands"] == metadata

Tests/test_pyarrow.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import json
 from typing import Any, NamedTuple
 
 import pytest
@@ -244,3 +245,29 @@ def test_from_int32array(mode: str, data_tp: DataShape, mask: list[int] | None)
     img = Image.fromarrow(arr, mode, TEST_IMAGE_SIZE)
 
     _test_img_equals_int32_pyarray(img, arr, mask, elts_per_pixel)
+
+
+@pytest.mark.parametrize(
+    "mode, metadata",
+    (
+        ("LA", ["L", "X", "X", "A"]),
+        ("RGB", ["R", "G", "B", "X"]),
+        ("RGBX", ["R", "G", "B", "X"]),
+        ("RGBA", ["R", "G", "B", "A"]),
+        ("CMYK", ["C", "M", "Y", "K"]),
+        ("YCbCr", ["Y", "Cb", "Cr", "X"]),
+        ("HSV", ["H", "S", "V", "X"]),
+    ),
+)
+def test_image_metadata(mode: str, metadata: list[str]) -> None:
+    img = hopper(mode)
+
+    arr = pyarrow.array(img)  # type: ignore[call-overload]
+
+    assert arr.type.field(0).metadata
+    assert arr.type.field(0).metadata[b"image"]
+
+    parsed_metadata = json.loads(arr.type.field(0).metadata[b"image"].decode("utf8"))
+
+    assert "bands" in parsed_metadata
+    assert parsed_metadata["bands"] == metadata

checks/32bit_segfault_check.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python3
 from __future__ import annotations
 
 import sys

checks/check_imaging_leaks.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python3
 from __future__ import annotations
 
 import sys

depends/install_libavif.sh

@@ -59,6 +59,6 @@ cmake \
     "${LIBAVIF_CMAKE_FLAGS[@]}" \
     .
 
-sudo make install
+make install
 
 popd

depends/install_openjpeg.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 # install openjpeg
 
-archive=openjpeg-2.5.3
+archive=openjpeg-2.5.4
 
 ./download-and-extract.sh $archive https://raw.githubusercontent.com/python-pillow/pillow-depends/main/$archive.tar.gz
 

depends/install_raqm.sh

@@ -8,6 +8,6 @@ archive=libraqm-0.10.3
 
 pushd $archive
 
-meson build --prefix=/usr && sudo ninja -C build install
+meson build --prefix=/usr && ninja -C build install
 
 popd

docs/installation/building-from-source.rst

@@ -44,7 +44,7 @@ Many of Pillow's features require external libraries:
 
 * **libtiff** provides compressed TIFF functionality
 
-  * Pillow has been tested with libtiff versions **4.0-4.7.0**
+  * Pillow has been tested with libtiff versions **4.0-4.7.1**
 
 * **libfreetype** provides type related services
 
@@ -58,7 +58,7 @@ Many of Pillow's features require external libraries:
 * **openjpeg** provides JPEG 2000 functionality.
 
   * Pillow has been tested with openjpeg **2.0.0**, **2.1.0**, **2.3.1**,
-    **2.4.0**, **2.5.0**, **2.5.2** and **2.5.3**.
+    **2.4.0**, **2.5.0**, **2.5.2**, **2.5.3** and **2.5.4**.
   * Pillow does **not** support the earlier **1.5** series which ships
     with Debian Jessie.
 

docs/installation/platform-support.rst

@@ -39,9 +39,9 @@ These platforms are built and tested for every change.
 +----------------------------------+----------------------------+---------------------+
 | Gentoo                           | 3.12                       | x86-64              |
 +----------------------------------+----------------------------+---------------------+
-| macOS 13 Ventura                 | 3.10                       | x86-64              |
-+----------------------------------+----------------------------+---------------------+
-| macOS 15 Sequoia                 | 3.11, 3.12, 3.13, 3.14     | arm64               |
+| macOS 15 Sequoia                 | 3.10                       | x86-64              |
+|                                  +----------------------------+---------------------+
+|                                  | 3.11, 3.12, 3.13, 3.14,    | arm64               |
 |                                  | PyPy3                      |                     |
 +----------------------------------+----------------------------+---------------------+
 | Ubuntu Linux 22.04 LTS (Jammy)   | 3.10                       | x86-64              |
@@ -75,6 +75,8 @@ These platforms have been reported to work at the versions mentioned.
 | Operating system                 | | Tested Python            | | Latest tested  | | Tested     |
 |                                  | | versions                 | | Pillow version | | processors |
 +==================================+============================+==================+==============+
+| macOS 26 Tahoe                   | 3.9, 3.10, 3.11, 3.12, 3.13| 11.3.0           |arm           |
++----------------------------------+----------------------------+------------------+--------------+
 | macOS 15 Sequoia                 | 3.9, 3.10, 3.11, 3.12, 3.13| 11.3.0           |arm           |
 |                                  +----------------------------+------------------+              |
 |                                  | 3.8                        | 10.4.0           |              |

docs/reference/ImageDraw.rst

@@ -57,6 +57,43 @@ Color names
 
 See :ref:`color-names` for the color names supported by Pillow.
 
+Alpha channel
+^^^^^^^^^^^^^
+
+By default, when drawing onto an existing image, the image's pixel values are simply
+replaced by the new color::
+
+    im = Image.new("RGBA", (1, 1), (255, 0, 0))
+    d = ImageDraw.Draw(im)
+    d.rectangle((0, 0, 1, 1), (0, 255, 0, 127))
+    assert im.getpixel((0, 0)) == (0, 255, 0, 127)
+
+    # Alpha channel values have no effect when drawing with RGB mode
+    im = Image.new("RGB", (1, 1), (255, 0, 0))
+    d = ImageDraw.Draw(im)
+    d.rectangle((0, 0, 1, 1), (0, 255, 0, 127))
+    assert im.getpixel((0, 0)) == (0, 255, 0)
+
+If you would like to combine translucent color with an RGB image, then initialize the
+ImageDraw instance with the RGBA mode::
+
+    from PIL import Image, ImageDraw
+    im = Image.new("RGB", (1, 1), (255, 0, 0))
+    d = ImageDraw.Draw(im, "RGBA")
+    d.rectangle((0, 0, 1, 1), (0, 255, 0, 127))
+    assert im.getpixel((0, 0)) == (128, 127, 0)
+
+If you would like to combine translucent color with an RGBA image underneath, you will
+need to combine multiple images::
+
+    from PIL import Image, ImageDraw
+    im = Image.new("RGBA", (1, 1), (255, 0, 0, 255))
+    im2 = Image.new("RGBA", (1, 1))
+    d = ImageDraw.Draw(im2)
+    d.rectangle((0, 0, 1, 1), (0, 255, 0, 127))
+    im.paste(im2.convert("RGB"), mask=im2)
+    assert im.getpixel((0, 0)) == (128, 127, 0, 255)
+
 Fonts
 ^^^^^
 
@@ -545,6 +582,8 @@ Methods
         hello_world = hello + world  # kerning is disabled, no need to adjust
         assert hello_world == draw.textlength("HelloWorld", font, features=["-kern"])  # True
 
+    .. seealso:: :py:meth:`PIL.ImageText.Text.get_length`
+
     .. versionadded:: 8.0.0
 
     :param text: Text to be measured. May not contain any newline characters.
@@ -646,6 +685,8 @@ Methods
     1/64 pixel precision. The bounding box includes extra margins for
     some fonts, e.g. italics or accents.
 
+    .. seealso:: :py:meth:`PIL.ImageText.Text.get_bbox`
+
     .. versionadded:: 8.0.0
 
     :param xy: The anchor coordinates of the text.

docs/reference/ImageText.rst

@@ -0,0 +1,61 @@
+.. py:module:: PIL.ImageText
+.. py:currentmodule:: PIL.ImageText
+
+:py:mod:`~PIL.ImageText` module
+===============================
+
+The :py:mod:`~PIL.ImageText` module defines a :py:class:`~PIL.ImageText.Text` class.
+Instances of this class provide a way to use fonts with text strings or bytes. The
+result is a simple API to apply styling to pieces of text and measure or draw them.
+
+Example
+-------
+
+::
+
+    from PIL import Image, ImageDraw, ImageFont, ImageText
+    font = ImageFont.truetype("Tests/fonts/FreeMono.ttf", 24)
+
+    text = ImageText.Text("Hello world", font)
+    text.embed_color()
+    text.stroke(2, "#0f0")
+
+    print(text.get_length())  # 154.0
+    print(text.get_bbox())  # (-2, 3, 156, 22)
+
+    im = Image.new("RGB", text.get_bbox()[2:])
+    d = ImageDraw.Draw(im)
+    d.text((0, 0), text, "#f00")
+
+Comparison
+----------
+
+Without ``ImageText.Text``::
+
+  from PIL import Image, ImageDraw
+  im = Image.new(mode, size)
+  d = ImageDraw.Draw(im)
+
+  d.textlength(text, font, direction, features, language, embedded_color)
+  d.multiline_textbbox(xy, text, font, anchor, spacing, align, direction, features, language, stroke_width, embedded_color)
+  d.text(xy, text, fill, font, anchor, spacing, align, direction, features, language, stroke_width, stroke_fill, embedded_color)
+
+With ``ImageText.Text``::
+
+  from PIL import ImageText
+  text = ImageText.Text(text, font, mode, spacing, direction, features, language)
+  text.embed_color()
+  text.stroke(stroke_width, stroke_fill)
+
+  text.get_length()
+  text.get_bbox(xy, anchor, align)
+
+  im = Image.new(mode, size)
+  d = ImageDraw.Draw(im)
+  d.text(xy, text, fill, anchor=anchor, align=align)
+
+Methods
+-------
+
+.. autoclass:: PIL.ImageText.Text
+    :members:

docs/reference/index.rst

@@ -24,6 +24,7 @@ Reference
    ImageSequence
    ImageShow
    ImageStat
+   ImageText
    ImageTk
    ImageTransform
    ImageWin

docs/releasenotes/12.0.0.rst

@@ -1,19 +1,6 @@
 12.0.0
 ------
 
-Security
-========
-
-TODO
-^^^^
-
-TODO
-
-:cve:`YYYY-XXXXX`: TODO
-^^^^^^^^^^^^^^^^^^^^^^^
-
-TODO
-
 Backwards incompatible changes
 ==============================
 
@@ -132,18 +119,43 @@ Pillow 13 (2026-10-15). They have been set to ``None`` since Pillow 2.3.0.
 API changes
 ===========
 
-TODO
-^^^^
+Image.alpha_composite: LA images
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-TODO
+:py:meth:`~PIL.Image.alpha_composite` can now use LA images as well as RGBA.
 
 API additions
 =============
 
-TODO
-^^^^
+Added ImageText.Text
+^^^^^^^^^^^^^^^^^^^^
 
-TODO
+:py:class:`PIL.ImageText.Text` has been added, as a simpler way to use fonts with text
+strings or bytes.
+
+Without ``ImageText.Text``::
+
+  from PIL import Image, ImageDraw
+  im = Image.new(mode, size)
+  d = ImageDraw.Draw(im)
+
+  d.textlength(text, font, direction, features, language, embedded_color)
+  d.multiline_textbbox(xy, text, font, anchor, spacing, align, direction, features, language, stroke_width, embedded_color)
+  d.text(xy, text, fill, font, anchor, spacing, align, direction, features, language, stroke_width, stroke_fill, embedded_color)
+
+With ``ImageText.Text``::
+
+  from PIL import ImageText
+  text = ImageText.Text(text, font, mode, spacing, direction, features, language)
+  text.embed_color()
+  text.stroke(stroke_width, stroke_fill)
+
+  text.get_length()
+  text.get_bbox(xy, anchor, align)
+
+  im = Image.new(mode, size)
+  d = ImageDraw.Draw(im)
+  d.text(xy, text, fill, anchor=anchor, align=align)
 
 Other changes
 =============

pyproject.toml

@@ -57,6 +57,9 @@ optional-dependencies.mic = [
   "olefile",
 ]
 optional-dependencies.test-arrow = [
+  "arro3-compute",
+  "arro3-core",
+  "nanoarrow",
   "pyarrow",
 ]
 

setup.py

@@ -21,6 +21,10 @@ from pybind11.setup_helpers import ParallelCompile
 from setuptools import Extension, setup
 from setuptools.command.build_ext import build_ext
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from setuptools import _BuildInfo
+
 configuration: dict[str, list[str]] = {}
 
 # parse configuration from _custom_build/backend.py
@@ -1072,16 +1076,20 @@ def debug_build() -> bool:
     return hasattr(sys, "gettotalrefcount") or FUZZING_BUILD
 
 
+libraries: list[tuple[str, _BuildInfo]] = [
+    ("pil_imaging_mode", {"sources": ["src/libImaging/Mode.c"]}),
+]
+
 files: list[str | os.PathLike[str]] = ["src/_imaging.c"]
 for src_file in _IMAGING:
     files.append("src/" + src_file + ".c")
 for src_file in _LIB_IMAGING:
     files.append(os.path.join("src/libImaging", src_file + ".c"))
 ext_modules = [
-    Extension("PIL._imaging", files),
-    Extension("PIL._imagingft", ["src/_imagingft.c"]),
-    Extension("PIL._imagingcms", ["src/_imagingcms.c"]),
-    Extension("PIL._webp", ["src/_webp.c"]),
+    Extension("PIL._imaging", files, libraries=["pil_imaging_mode"]),
+    Extension("PIL._imagingft", ["src/_imagingft.c"], libraries=["pil_imaging_mode"]),
+    Extension("PIL._imagingcms", ["src/_imagingcms.c"], libraries=["pil_imaging_mode"]),
+    Extension("PIL._webp", ["src/_webp.c"], libraries=["pil_imaging_mode"]),
     Extension("PIL._avif", ["src/_avif.c"]),
     Extension("PIL._imagingtk", ["src/_imagingtk.c", "src/Tk/tkImaging.c"]),
     Extension("PIL._imagingmath", ["src/_imagingmath.c"]),
@@ -1093,6 +1101,7 @@ try:
     setup(
         cmdclass={"build_ext": pil_build_ext},
         ext_modules=ext_modules,
+        libraries=libraries,
         zip_safe=not (debug_build() or PLATFORM_MINGW),
     )
 except RequiredDependencyException as err:

src/PIL/CurImagePlugin.py

@@ -17,7 +17,7 @@
 #
 from __future__ import annotations
 
-from . import BmpImagePlugin, Image, ImageFile
+from . import BmpImagePlugin, Image
 from ._binary import i16le as i16
 from ._binary import i32le as i32
 
@@ -38,6 +38,7 @@ class CurImageFile(BmpImagePlugin.BmpImageFile):
     format_description = "Windows Cursor"
 
     def _open(self) -> None:
+        assert self.fp is not None
         offset = self.fp.tell()
 
         # check magic
@@ -63,8 +64,7 @@ class CurImageFile(BmpImagePlugin.BmpImageFile):
 
         # patch up the bitmap height
         self._size = self.size[0], self.size[1] // 2
-        d, e, o, a = self.tile[0]
-        self.tile[0] = ImageFile._Tile(d, (0, 0) + self.size, o, a)
+        self.tile = [self.tile[0]._replace(extents=(0, 0) + self.size)]
 
 
 #

src/PIL/EpsImagePlugin.py

@@ -354,6 +354,9 @@ class EpsImageFile(ImageFile.ImageFile):
                 read_comment(s)
             elif bytes_mv[:9] == b"%%Trailer":
                 trailer_reached = True
+            elif bytes_mv[:14] == b"%%BeginBinary:":
+                bytecount = int(byte_arr[14:bytes_read])
+                self.fp.seek(bytecount, os.SEEK_CUR)
             bytes_read = 0
 
         # A "BoundingBox" is always required,

src/PIL/FliImagePlugin.py

@@ -48,8 +48,14 @@ class FliImageFile(ImageFile.ImageFile):
 
     def _open(self) -> None:
         # HEAD
+        assert self.fp is not None
         s = self.fp.read(128)
-        if not (_accept(s) and s[20:22] == b"\x00\x00"):
+        if not (
+            _accept(s)
+            and s[20:22] == b"\x00" * 2
+            and s[42:80] == b"\x00" * 38
+            and s[88:] == b"\x00" * 40
+        ):
             msg = "not an FLI/FLC file"
             raise SyntaxError(msg)
 
@@ -77,8 +83,7 @@ class FliImageFile(ImageFile.ImageFile):
 
         if i16(s, 4) == 0xF100:
             # prefix chunk; ignore it
-            self.__offset = self.__offset + i32(s)
-            self.fp.seek(self.__offset)
+            self.fp.seek(self.__offset + i32(s))
             s = self.fp.read(16)
 
         if i16(s, 4) == 0xF1FA:
@@ -111,6 +116,7 @@ class FliImageFile(ImageFile.ImageFile):
         # load palette
 
         i = 0
+        assert self.fp is not None
         for e in range(i16(self.fp.read(2))):
             s = self.fp.read(2)
             i = i + s[0]

src/PIL/Image.py

@@ -1009,8 +1009,14 @@ class Image:
                 new_im.info["transparency"] = transparency
             return new_im
 
-        if mode == "P" and self.mode == "RGBA":
+        if self.mode == "RGBA":
+            if mode == "P":
                 return self.quantize(colors)
+            elif mode == "PA":
+                r, g, b, a = self.split()
+                rgb = merge("RGB", (r, g, b))
+                p = rgb.quantize(colors)
+                return merge("PA", (p, a))
 
         trns = None
         delete_trns = False
@@ -1142,7 +1148,7 @@ class Image:
                 raise ValueError(msg) from e
 
         new_im = self._new(im)
-        if mode == "P" and palette != Palette.ADAPTIVE:
+        if mode in ("P", "PA") and palette != Palette.ADAPTIVE:
             from . import ImagePalette
 
             new_im.palette = ImagePalette.ImagePalette("RGB", im.getpalette("RGB"))
@@ -1336,12 +1342,6 @@ class Image:
         """
         pass
 
-    def _expand(self, xmargin: int, ymargin: int | None = None) -> Image:
-        if ymargin is None:
-            ymargin = xmargin
-        self.load()
-        return self._new(self.im.expand(xmargin, ymargin))
-
     def filter(self, filter: ImageFilter.Filter | type[ImageFilter.Filter]) -> Image:
         """
         Filters this image using the given filter.  For a list of
@@ -2070,9 +2070,7 @@ class Image:
         :param value: The pixel value.
         """
 
-        if self.readonly:
-            self._copy()
-        self.load()
+        self._ensure_mutable()
 
         if (
             self.mode in ("P", "PA")

src/PIL/ImageDraw.py

@@ -36,7 +36,7 @@ import struct
 from collections.abc import Sequence
 from typing import cast
 
-from . import Image, ImageColor
+from . import Image, ImageColor, ImageText
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:
@@ -45,13 +45,11 @@ if TYPE_CHECKING:
     from typing import Any, AnyStr
 
     from . import ImageDraw2, ImageFont
-    from ._typing import Coords
+    from ._typing import Coords, _Ink
 
 # experimental access to the outline API
 Outline: Callable[[], Image.core._Outline] = Image.core.outline
 
-_Ink = float | tuple[int, ...] | str
-
 """
 A simple 2D drawing interface for PIL images.
 <p>
@@ -76,9 +74,7 @@ class ImageDraw:
            must be the same as the image mode.  If omitted, the mode
            defaults to the mode of the image.
         """
-        im.load()
-        if im.readonly:
-            im._copy()  # make it writeable
+        im._ensure_mutable()
         blend = 0
         if mode is None:
             mode = im.mode
@@ -539,15 +535,10 @@ class ImageDraw:
                     right[3] -= r + 1
                 self.draw.draw_rectangle(right, ink, 1)
 
-    def _multiline_check(self, text: AnyStr) -> bool:
-        split_character = "\n" if isinstance(text, str) else b"\n"
-
-        return split_character in text
-
     def text(
         self,
         xy: tuple[float, float],
-        text: AnyStr,
+        text: AnyStr | ImageText.Text,
         fill: _Ink | None = None,
         font: (
             ImageFont.ImageFont
@@ -568,29 +559,18 @@ class ImageDraw:
         **kwargs: Any,
     ) -> None:
         """Draw text."""
-        if embedded_color and self.mode not in ("RGB", "RGBA"):
-            msg = "Embedded color supported only in RGB and RGBA modes"
-            raise ValueError(msg)
-
+        if isinstance(text, ImageText.Text):
+            image_text = text
+        else:
             if font is None:
                 font = self._getfont(kwargs.get("font_size"))
-
-        if self._multiline_check(text):
-            return self.multiline_text(
-                xy,
-                text,
-                fill,
-                font,
-                anchor,
-                spacing,
-                align,
-                direction,
-                features,
-                language,
-                stroke_width,
-                stroke_fill,
-                embedded_color,
+            image_text = ImageText.Text(
+                text, font, self.mode, spacing, direction, features, language
             )
+            if embedded_color:
+                image_text.embed_color()
+            if stroke_width:
+                image_text.stroke(stroke_width, stroke_fill)
 
         def getink(fill: _Ink | None) -> int:
             ink, fill_ink = self._getink(fill)
@@ -599,6 +579,20 @@ class ImageDraw:
                 return fill_ink
             return ink
 
+        ink = getink(fill)
+        if ink is None:
+            return
+
+        stroke_ink = None
+        if image_text.stroke_width:
+            stroke_ink = (
+                getink(image_text.stroke_fill)
+                if image_text.stroke_fill is not None
+                else ink
+            )
+
+        for xy, anchor, line in image_text._split(xy, anchor, align):
+
             def draw_text(ink: int, stroke_width: float = 0) -> None:
                 mode = self.fontmode
                 if stroke_width == 0 and embedded_color:
@@ -608,8 +602,8 @@ class ImageDraw:
                     coord.append(int(xy[i]))
                 start = (math.modf(xy[0])[0], math.modf(xy[1])[0])
                 try:
-                mask, offset = font.getmask2(  # type: ignore[union-attr,misc]
-                    text,
+                    mask, offset = image_text.font.getmask2(  # type: ignore[union-attr,misc]
+                        line,
                         mode,
                         direction=direction,
                         features=features,
@@ -625,8 +619,8 @@ class ImageDraw:
                     coord = [coord[0] + offset[0], coord[1] + offset[1]]
                 except AttributeError:
                     try:
-                    mask = font.getmask(  # type: ignore[misc]
-                        text,
+                        mask = image_text.font.getmask(  # type: ignore[misc]
+                            line,
                             mode,
                             direction,
                             features,
@@ -639,9 +633,10 @@ class ImageDraw:
                             **kwargs,
                         )
                     except TypeError:
-                    mask = font.getmask(text)
+                        mask = image_text.font.getmask(line)
                 if mode == "RGBA":
-                # font.getmask2(mode="RGBA") returns color in RGB bands and mask in A
+                    # image_text.font.getmask2(mode="RGBA")
+                    # returns color in RGB bands and mask in A
                     # extract mask and set text alpha
                     color, mask = mask, mask.getband(3)
                     ink_alpha = struct.pack("i", ink)[3]
@@ -654,15 +649,9 @@ class ImageDraw:
                 else:
                     self.draw.draw_bitmap(coord, mask, ink)
 
-        ink = getink(fill)
-        if ink is not None:
-            stroke_ink = None
-            if stroke_width:
-                stroke_ink = getink(stroke_fill) if stroke_fill is not None else ink
-
             if stroke_ink is not None:
                 # Draw stroked text
-                draw_text(stroke_ink, stroke_width)
+                draw_text(stroke_ink, image_text.stroke_width)
 
                 # Draw normal text
                 if ink != stroke_ink:
@@ -671,132 +660,6 @@ class ImageDraw:
                 # Only draw normal text
                 draw_text(ink)
 
-    def _prepare_multiline_text(
-        self,
-        xy: tuple[float, float],
-        text: AnyStr,
-        font: (
-            ImageFont.ImageFont
-            | ImageFont.FreeTypeFont
-            | ImageFont.TransposedFont
-            | None
-        ),
-        anchor: str | None,
-        spacing: float,
-        align: str,
-        direction: str | None,
-        features: list[str] | None,
-        language: str | None,
-        stroke_width: float,
-        embedded_color: bool,
-        font_size: float | None,
-    ) -> tuple[
-        ImageFont.ImageFont | ImageFont.FreeTypeFont | ImageFont.TransposedFont,
-        list[tuple[tuple[float, float], str, AnyStr]],
-    ]:
-        if anchor is None:
-            anchor = "lt" if direction == "ttb" else "la"
-        elif len(anchor) != 2:
-            msg = "anchor must be a 2 character string"
-            raise ValueError(msg)
-        elif anchor[1] in "tb" and direction != "ttb":
-            msg = "anchor not supported for multiline text"
-            raise ValueError(msg)
-
-        if font is None:
-            font = self._getfont(font_size)
-
-        lines = text.split("\n" if isinstance(text, str) else b"\n")
-        line_spacing = (
-            self.textbbox((0, 0), "A", font, stroke_width=stroke_width)[3]
-            + stroke_width
-            + spacing
-        )
-
-        top = xy[1]
-        parts = []
-        if direction == "ttb":
-            left = xy[0]
-            for line in lines:
-                parts.append(((left, top), anchor, line))
-                left += line_spacing
-        else:
-            widths = []
-            max_width: float = 0
-            for line in lines:
-                line_width = self.textlength(
-                    line,
-                    font,
-                    direction=direction,
-                    features=features,
-                    language=language,
-                    embedded_color=embedded_color,
-                )
-                widths.append(line_width)
-                max_width = max(max_width, line_width)
-
-            if anchor[1] == "m":
-                top -= (len(lines) - 1) * line_spacing / 2.0
-            elif anchor[1] == "d":
-                top -= (len(lines) - 1) * line_spacing
-
-            for idx, line in enumerate(lines):
-                left = xy[0]
-                width_difference = max_width - widths[idx]
-
-                # align by align parameter
-                if align in ("left", "justify"):
-                    pass
-                elif align == "center":
-                    left += width_difference / 2.0
-                elif align == "right":
-                    left += width_difference
-                else:
-                    msg = 'align must be "left", "center", "right" or "justify"'
-                    raise ValueError(msg)
-
-                if (
-                    align == "justify"
-                    and width_difference != 0
-                    and idx != len(lines) - 1
-                ):
-                    words = line.split(" " if isinstance(text, str) else b" ")
-                    if len(words) > 1:
-                        # align left by anchor
-                        if anchor[0] == "m":
-                            left -= max_width / 2.0
-                        elif anchor[0] == "r":
-                            left -= max_width
-
-                        word_widths = [
-                            self.textlength(
-                                word,
-                                font,
-                                direction=direction,
-                                features=features,
-                                language=language,
-                                embedded_color=embedded_color,
-                            )
-                            for word in words
-                        ]
-                        word_anchor = "l" + anchor[1]
-                        width_difference = max_width - sum(word_widths)
-                        for i, word in enumerate(words):
-                            parts.append(((left, top), word_anchor, word))
-                            left += word_widths[i] + width_difference / (len(words) - 1)
-                        top += line_spacing
-                        continue
-
-                # align left by anchor
-                if anchor[0] == "m":
-                    left -= width_difference / 2.0
-                elif anchor[0] == "r":
-                    left -= width_difference
-                parts.append(((left, top), anchor, line))
-                top += line_spacing
-
-        return font, parts
-
     def multiline_text(
         self,
         xy: tuple[float, float],
@@ -820,9 +683,10 @@ class ImageDraw:
         *,
         font_size: float | None = None,
     ) -> None:
-        font, lines = self._prepare_multiline_text(
+        return self.text(
             xy,
             text,
+            fill,
             font,
             anchor,
             spacing,
@@ -831,23 +695,9 @@ class ImageDraw:
             features,
             language,
             stroke_width,
+            stroke_fill,
             embedded_color,
-            font_size,
-        )
-
-        for xy, anchor, line in lines:
-            self.text(
-                xy,
-                line,
-                fill,
-                font,
-                anchor,
-                direction=direction,
-                features=features,
-                language=language,
-                stroke_width=stroke_width,
-                stroke_fill=stroke_fill,
-                embedded_color=embedded_color,
+            font_size=font_size,
         )
 
     def textlength(
@@ -867,17 +717,19 @@ class ImageDraw:
         font_size: float | None = None,
     ) -> float:
         """Get the length of a given string, in pixels with 1/64 precision."""
-        if self._multiline_check(text):
-            msg = "can't measure length of multiline text"
-            raise ValueError(msg)
-        if embedded_color and self.mode not in ("RGB", "RGBA"):
-            msg = "Embedded color supported only in RGB and RGBA modes"
-            raise ValueError(msg)
-
         if font is None:
             font = self._getfont(font_size)
-        mode = "RGBA" if embedded_color else self.fontmode
-        return font.getlength(text, mode, direction, features, language)
+        image_text = ImageText.Text(
+            text,
+            font,
+            self.mode,
+            direction=direction,
+            features=features,
+            language=language,
+        )
+        if embedded_color:
+            image_text.embed_color()
+        return image_text.get_length()
 
     def textbbox(
         self,
@@ -901,33 +753,16 @@ class ImageDraw:
         font_size: float | None = None,
     ) -> tuple[float, float, float, float]:
         """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"
-            raise ValueError(msg)
-
         if font is None:
             font = self._getfont(font_size)
-
-        if self._multiline_check(text):
-            return self.multiline_textbbox(
-                xy,
-                text,
-                font,
-                anchor,
-                spacing,
-                align,
-                direction,
-                features,
-                language,
-                stroke_width,
-                embedded_color,
+        image_text = ImageText.Text(
+            text, font, self.mode, spacing, direction, features, language
         )
-
-        mode = "RGBA" if embedded_color else self.fontmode
-        bbox = font.getbbox(
-            text, mode, direction, features, language, stroke_width, anchor
-        )
-        return bbox[0] + xy[0], bbox[1] + xy[1], bbox[2] + xy[0], bbox[3] + xy[1]
+        if embedded_color:
+            image_text.embed_color()
+        if stroke_width:
+            image_text.stroke(stroke_width)
+        return image_text.get_bbox(xy, anchor, align)
 
     def multiline_textbbox(
         self,
@@ -950,7 +785,7 @@ class ImageDraw:
         *,
         font_size: float | None = None,
     ) -> tuple[float, float, float, float]:
-        font, lines = self._prepare_multiline_text(
+        return self.textbbox(
             xy,
             text,
             font,
@@ -962,37 +797,9 @@ class ImageDraw:
             language,
             stroke_width,
             embedded_color,
-            font_size,
+            font_size=font_size,
         )
 
-        bbox: tuple[float, float, float, float] | None = None
-
-        for xy, anchor, line in lines:
-            bbox_line = self.textbbox(
-                xy,
-                line,
-                font,
-                anchor,
-                direction=direction,
-                features=features,
-                language=language,
-                stroke_width=stroke_width,
-                embedded_color=embedded_color,
-            )
-            if bbox is None:
-                bbox = bbox_line
-            else:
-                bbox = (
-                    min(bbox[0], bbox_line[0]),
-                    min(bbox[1], bbox_line[1]),
-                    max(bbox[2], bbox_line[2]),
-                    max(bbox[3], bbox_line[3]),
-                )
-
-        if bbox is None:
-            return xy[0], xy[1], xy[0], xy[1]
-        return bbox
-
 
 def Draw(im: Image.Image, mode: str | None = None) -> ImageDraw:
     """

src/PIL/ImageFile.py

@@ -313,6 +313,9 @@ class ImageFile(Image.Image):
                 and args[0] == self.mode
                 and args[0] in Image._MAPMODES
             ):
+                if offset < 0:
+                    msg = "Tile offset cannot be negative"
+                    raise ValueError(msg)
                 try:
                     # use mmap, if possible
                     import mmap

src/PIL/ImageFont.py

@@ -125,11 +125,16 @@ class ImageFont:
             image.close()
 
     def _load_pilfont_data(self, file: IO[bytes], image: Image.Image) -> None:
+        # check image
+        if image.mode not in ("1", "L"):
+            msg = "invalid font image mode"
+            raise TypeError(msg)
+
         # read PILfont header
-        if file.readline() != b"PILfont\n":
+        if file.read(8) != b"PILfont\n":
             msg = "Not a PILfont file"
             raise SyntaxError(msg)
-        file.readline().split(b";")
+        file.readline()
         self.info = []  # FIXME: should be a dictionary
         while True:
             s = file.readline()
@@ -140,11 +145,6 @@ class ImageFont:
         # read PILfont metrics
         data = file.read(256 * 20)
 
-        # check image
-        if image.mode not in ("1", "L"):
-            msg = "invalid font image mode"
-            raise TypeError(msg)
-
         image.load()
 
         self.font = Image.core.font(image.im, data)

src/PIL/ImageOps.py

@@ -499,14 +499,15 @@ def expand(
     height = top + image.size[1] + bottom
     color = _color(fill, image.mode)
     if image.palette:
-        palette = ImagePalette.ImagePalette(palette=image.getpalette())
+        mode = image.palette.mode
+        palette = ImagePalette.ImagePalette(mode, image.getpalette(mode))
         if isinstance(color, tuple) and (len(color) == 3 or len(color) == 4):
             color = palette.getcolor(color)
     else:
         palette = None
     out = Image.new(image.mode, (width, height), color)
     if palette:
-        out.putpalette(palette.palette)
+        out.putpalette(palette.palette, mode)
     out.paste(image, (left, top))
     return out
 

src/PIL/ImageText.py

@@ -0,0 +1,318 @@
+from __future__ import annotations
+
+from . import ImageFont
+from ._typing import _Ink
+
+
+class Text:
+    def __init__(
+        self,
+        text: str | bytes,
+        font: (
+            ImageFont.ImageFont
+            | ImageFont.FreeTypeFont
+            | ImageFont.TransposedFont
+            | None
+        ) = None,
+        mode: str = "RGB",
+        spacing: float = 4,
+        direction: str | None = None,
+        features: list[str] | None = None,
+        language: str | None = None,
+    ) -> None:
+        """
+        :param text: String to be drawn.
+        :param font: Either an :py:class:`~PIL.ImageFont.ImageFont` instance,
+                     :py:class:`~PIL.ImageFont.FreeTypeFont` instance,
+                     :py:class:`~PIL.ImageFont.TransposedFont` instance or ``None``. If
+                     ``None``, the default font from :py:meth:`.ImageFont.load_default`
+                     will be used.
+        :param mode: The image mode this will be used with.
+        :param spacing: The number of pixels between lines.
+        :param direction: Direction of the text. It can be ``"rtl"`` (right to left),
+                          ``"ltr"`` (left to right) or ``"ttb"`` (top to bottom).
+                          Requires libraqm.
+        :param features: A list of OpenType font features to be used during text
+                         layout. This is usually used to turn on optional font features
+                         that are not enabled by default, for example ``"dlig"`` or
+                         ``"ss01"``, but can be also used to turn off default font
+                         features, for example ``"-liga"`` to disable ligatures or
+                         ``"-kern"`` to disable kerning.  To get all supported
+                         features, see `OpenType docs`_.
+                         Requires libraqm.
+        :param language: Language of the text. Different languages may use
+                         different glyph shapes or ligatures. This parameter tells
+                         the font which language the text is in, and to apply the
+                         correct substitutions as appropriate, if available.
+                         It should be a `BCP 47 language code`_.
+                         Requires libraqm.
+        """
+        self.text = text
+        self.font = font or ImageFont.load_default()
+
+        self.mode = mode
+        self.spacing = spacing
+        self.direction = direction
+        self.features = features
+        self.language = language
+
+        self.embedded_color = False
+
+        self.stroke_width: float = 0
+        self.stroke_fill: _Ink | None = None
+
+    def embed_color(self) -> None:
+        """
+        Use embedded color glyphs (COLR, CBDT, SBIX).
+        """
+        if self.mode not in ("RGB", "RGBA"):
+            msg = "Embedded color supported only in RGB and RGBA modes"
+            raise ValueError(msg)
+        self.embedded_color = True
+
+    def stroke(self, width: float = 0, fill: _Ink | None = None) -> None:
+        """
+        :param width: The width of the text stroke.
+        :param fill: Color to use for the text stroke when drawing. If not given, will
+                     default to the ``fill`` parameter from
+                     :py:meth:`.ImageDraw.ImageDraw.text`.
+        """
+        self.stroke_width = width
+        self.stroke_fill = fill
+
+    def _get_fontmode(self) -> str:
+        if self.mode in ("1", "P", "I", "F"):
+            return "1"
+        elif self.embedded_color:
+            return "RGBA"
+        else:
+            return "L"
+
+    def get_length(self):
+        """
+        Returns length (in pixels with 1/64 precision) of text.
+
+        This is the amount by which following text should be offset.
+        Text bounding box may extend past the length in some fonts,
+        e.g. when using italics or accents.
+
+        The result is returned as a float; it is a whole number if using basic layout.
+
+        Note that the sum of two lengths may not equal the length of a concatenated
+        string due to kerning. If you need to adjust for kerning, include the following
+        character and subtract its length.
+
+        For example, instead of::
+
+            hello = ImageText.Text("Hello", font).get_length()
+            world = ImageText.Text("World", font).get_length()
+            helloworld = ImageText.Text("HelloWorld", font).get_length()
+            assert hello + world == helloworld
+
+        use::
+
+            hello = (
+                ImageText.Text("HelloW", font).get_length() -
+                ImageText.Text("W", font).get_length()
+            )  # adjusted for kerning
+            world = ImageText.Text("World", font).get_length()
+            helloworld = ImageText.Text("HelloWorld", font).get_length()
+            assert hello + world == helloworld
+
+        or disable kerning with (requires libraqm)::
+
+            hello = ImageText.Text("Hello", font, features=["-kern"]).get_length()
+            world = ImageText.Text("World", font, features=["-kern"]).get_length()
+            helloworld = ImageText.Text(
+                "HelloWorld", font, features=["-kern"]
+            ).get_length()
+            assert hello + world == helloworld
+
+        :return: Either width for horizontal text, or height for vertical text.
+        """
+        split_character = "\n" if isinstance(self.text, str) else b"\n"
+        if split_character in self.text:
+            msg = "can't measure length of multiline text"
+            raise ValueError(msg)
+        return self.font.getlength(
+            self.text,
+            self._get_fontmode(),
+            self.direction,
+            self.features,
+            self.language,
+        )
+
+    def _split(
+        self, xy: tuple[float, float], anchor: str | None, align: str
+    ) -> list[tuple[tuple[float, float], str, str | bytes]]:
+        if anchor is None:
+            anchor = "lt" if self.direction == "ttb" else "la"
+        elif len(anchor) != 2:
+            msg = "anchor must be a 2 character string"
+            raise ValueError(msg)
+
+        lines = (
+            self.text.split("\n")
+            if isinstance(self.text, str)
+            else self.text.split(b"\n")
+        )
+        if len(lines) == 1:
+            return [(xy, anchor, self.text)]
+
+        if anchor[1] in "tb" and self.direction != "ttb":
+            msg = "anchor not supported for multiline text"
+            raise ValueError(msg)
+
+        fontmode = self._get_fontmode()
+        line_spacing = (
+            self.font.getbbox(
+                "A",
+                fontmode,
+                None,
+                self.features,
+                self.language,
+                self.stroke_width,
+            )[3]
+            + self.stroke_width
+            + self.spacing
+        )
+
+        top = xy[1]
+        parts = []
+        if self.direction == "ttb":
+            left = xy[0]
+            for line in lines:
+                parts.append(((left, top), anchor, line))
+                left += line_spacing
+        else:
+            widths = []
+            max_width: float = 0
+            for line in lines:
+                line_width = self.font.getlength(
+                    line, fontmode, self.direction, self.features, self.language
+                )
+                widths.append(line_width)
+                max_width = max(max_width, line_width)
+
+            if anchor[1] == "m":
+                top -= (len(lines) - 1) * line_spacing / 2.0
+            elif anchor[1] == "d":
+                top -= (len(lines) - 1) * line_spacing
+
+            idx = -1
+            for line in lines:
+                left = xy[0]
+                idx += 1
+                width_difference = max_width - widths[idx]
+
+                # align by align parameter
+                if align in ("left", "justify"):
+                    pass
+                elif align == "center":
+                    left += width_difference / 2.0
+                elif align == "right":
+                    left += width_difference
+                else:
+                    msg = 'align must be "left", "center", "right" or "justify"'
+                    raise ValueError(msg)
+
+                if (
+                    align == "justify"
+                    and width_difference != 0
+                    and idx != len(lines) - 1
+                ):
+                    words = (
+                        line.split(" ") if isinstance(line, str) else line.split(b" ")
+                    )
+                    if len(words) > 1:
+                        # align left by anchor
+                        if anchor[0] == "m":
+                            left -= max_width / 2.0
+                        elif anchor[0] == "r":
+                            left -= max_width
+
+                        word_widths = [
+                            self.font.getlength(
+                                word,
+                                fontmode,
+                                self.direction,
+                                self.features,
+                                self.language,
+                            )
+                            for word in words
+                        ]
+                        word_anchor = "l" + anchor[1]
+                        width_difference = max_width - sum(word_widths)
+                        i = 0
+                        for word in words:
+                            parts.append(((left, top), word_anchor, word))
+                            left += word_widths[i] + width_difference / (len(words) - 1)
+                            i += 1
+                        top += line_spacing
+                        continue
+
+                # align left by anchor
+                if anchor[0] == "m":
+                    left -= width_difference / 2.0
+                elif anchor[0] == "r":
+                    left -= width_difference
+                parts.append(((left, top), anchor, line))
+                top += line_spacing
+
+        return parts
+
+    def get_bbox(
+        self,
+        xy: tuple[float, float] = (0, 0),
+        anchor: str | None = None,
+        align: str = "left",
+    ) -> tuple[float, float, float, float]:
+        """
+        Returns bounding box (in pixels) of text.
+
+        Use :py:meth:`get_length` to get the offset of following text with 1/64 pixel
+        precision. The bounding box includes extra margins for some fonts, e.g. italics
+        or accents.
+
+        :param xy: The anchor coordinates of the text.
+        :param anchor: The text anchor alignment. Determines the relative location of
+                       the anchor to the text. The default alignment is top left,
+                       specifically ``la`` for horizontal text and ``lt`` for
+                       vertical text. See :ref:`text-anchors` for details.
+        :param align: For multiline text, ``"left"``, ``"center"``, ``"right"`` or
+                      ``"justify"`` determines the relative alignment of lines. Use the
+                      ``anchor`` parameter to specify the alignment to ``xy``.
+
+        :return: ``(left, top, right, bottom)`` bounding box
+        """
+        bbox: tuple[float, float, float, float] | None = None
+        fontmode = self._get_fontmode()
+        for xy, anchor, line in self._split(xy, anchor, align):
+            bbox_line = self.font.getbbox(
+                line,
+                fontmode,
+                self.direction,
+                self.features,
+                self.language,
+                self.stroke_width,
+                anchor,
+            )
+            bbox_line = (
+                bbox_line[0] + xy[0],
+                bbox_line[1] + xy[1],
+                bbox_line[2] + xy[0],
+                bbox_line[3] + xy[1],
+            )
+            if bbox is None:
+                bbox = bbox_line
+            else:
+                bbox = (
+                    min(bbox[0], bbox_line[0]),
+                    min(bbox[1], bbox_line[1]),
+                    max(bbox[2], bbox_line[2]),
+                    max(bbox[3], bbox_line[3]),
+                )
+
+        if bbox is None:
+            return xy[0], xy[1], xy[0], xy[1]
+        return bbox

src/PIL/JpegImagePlugin.py

@@ -193,6 +193,8 @@ def SOF(self: JpegImageFile, marker: int) -> None:
     n = i16(self.fp.read(2)) - 2
     s = ImageFile._safe_read(self.fp, n)
     self._size = i16(s, 3), i16(s, 1)
+    if self._im is not None and self.size != self.im.size:
+        self._im = None
 
     self.bits = s[0]
     if self.bits != 8:

src/PIL/PcdImagePlugin.py

@@ -43,16 +43,21 @@ class PcdImageFile(ImageFile.ImageFile):
         if orientation == 1:
             self.tile_post_rotate = 90
         elif orientation == 3:
-            self.tile_post_rotate = -90
+            self.tile_post_rotate = 270
 
         self._mode = "RGB"
         self._size = (512, 768) if orientation in (1, 3) else (768, 512)
-        self.tile = [ImageFile._Tile("pcd", (0, 0) + self.size, 96 * 2048)]
+        self.tile = [ImageFile._Tile("pcd", (0, 0, 768, 512), 96 * 2048)]
+
+    def load_prepare(self) -> None:
+        if self._im is None and self.tile_post_rotate:
+            self.im = Image.core.new(self.mode, (768, 512))
+        ImageFile.ImageFile.load_prepare(self)
 
     def load_end(self) -> None:
         if self.tile_post_rotate:
             # Handle rotated PCDs
-            self.im = self.im.rotate(self.tile_post_rotate)
+            self.im = self.rotate(self.tile_post_rotate, expand=True).im
 
 
 #

src/PIL/PdfImagePlugin.py

@@ -27,7 +27,7 @@ import os
 import time
 from typing import IO, Any
 
-from . import Image, ImageFile, ImageSequence, PdfParser, __version__, features
+from . import Image, ImageFile, ImageSequence, PdfParser, features
 
 #
 # --------------------------------------------------------------------
@@ -221,7 +221,7 @@ def _save(
 
     existing_pdf.start_writing()
     existing_pdf.write_header()
-    existing_pdf.write_comment(f"created by Pillow {__version__} PDF driver")
+    existing_pdf.write_comment("created by Pillow PDF driver")
 
     #
     # pages

src/PIL/TiffImagePlugin.py

@@ -252,6 +252,7 @@ OPEN_INFO = {
     (II, 3, (1,), 1, (8,), ()): ("P", "P"),
     (MM, 3, (1,), 1, (8,), ()): ("P", "P"),
     (II, 3, (1,), 1, (8, 8), (0,)): ("P", "PX"),
+    (MM, 3, (1,), 1, (8, 8), (0,)): ("P", "PX"),
     (II, 3, (1,), 1, (8, 8), (2,)): ("PA", "PA"),
     (MM, 3, (1,), 1, (8, 8), (2,)): ("PA", "PA"),
     (II, 3, (1,), 2, (8,), ()): ("P", "P;R"),
@@ -1177,6 +1178,7 @@ class TiffImageFile(ImageFile.ImageFile):
         """Open the first image in a TIFF file"""
 
         # Header
+        assert self.fp is not None
         ifh = self.fp.read(8)
         if ifh[2] == 43:
             ifh += self.fp.read(8)
@@ -1343,6 +1345,7 @@ class TiffImageFile(ImageFile.ImageFile):
         # To be nice on memory footprint, if there's a
         # file descriptor, use that instead of reading
         # into a string in python.
+        assert self.fp is not None
         try:
             fp = hasattr(self.fp, "fileno") and self.fp.fileno()
             # flush the file descriptor, prevents error on pypy 2.4+
@@ -1936,9 +1939,10 @@ def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
                     types[tag] = TiffTags.LONG8
                 elif tag in ifd.tagtype:
                     types[tag] = ifd.tagtype[tag]
-                elif not (isinstance(value, (int, float, str, bytes))):
-                    continue
-                else:
+                elif isinstance(value, (int, float, str, bytes)) or (
+                    isinstance(value, tuple)
+                    and all(isinstance(v, (int, float, IFDRational)) for v in value)
+                ):
                     type = TiffTags.lookup(tag).type
                     if type:
                         types[tag] = type

src/PIL/TiffTags.py

@@ -203,6 +203,11 @@ _tags_v2: dict[int, tuple[str, int, int] | tuple[str, int, int, dict[str, int]]]
     531: ("YCbCrPositioning", SHORT, 1),
     532: ("ReferenceBlackWhite", RATIONAL, 6),
     700: ("XMP", BYTE, 0),
+    # Four private SGI tags
+    32995: ("Matteing", SHORT, 1),
+    32996: ("DataType", SHORT, 0),
+    32997: ("ImageDepth", LONG, 1),
+    32998: ("TileDepth", LONG, 1),
     33432: ("Copyright", ASCII, 1),
     33723: ("IptcNaaInfo", UNDEFINED, 1),
     34377: ("PhotoshopInfo", BYTE, 0),

src/PIL/_typing.py

@@ -27,6 +27,8 @@ else:
     Buffer = Any
 
 
+_Ink = float | tuple[int, ...] | str
+
 Coords = Sequence[float] | Sequence[Sequence[float]]
 
 

src/Tk/tkImaging.c

@@ -121,15 +121,16 @@ PyImagingPhotoPut(
 
     /* Mode */
 
-    if (strcmp(im->mode, "1") == 0 || strcmp(im->mode, "L") == 0) {
+    if (im->mode == IMAGING_MODE_1 || im->mode == IMAGING_MODE_L) {
         block.pixelSize = 1;
         block.offset[0] = block.offset[1] = block.offset[2] = block.offset[3] = 0;
-    } else if (strncmp(im->mode, "RGB", 3) == 0) {
+    } else if (im->mode == IMAGING_MODE_RGB || im->mode == IMAGING_MODE_RGBA ||
+               im->mode == IMAGING_MODE_RGBX || im->mode == IMAGING_MODE_RGBa) {
         block.pixelSize = 4;
         block.offset[0] = 0;
         block.offset[1] = 1;
         block.offset[2] = 2;
-        if (strcmp(im->mode, "RGBA") == 0) {
+        if (im->mode == IMAGING_MODE_RGBA) {
             block.offset[3] = 3; /* alpha (or reserved, under Tk 8.2) */
         } else {
             block.offset[3] = 0; /* no alpha */

src/_imaging.c

@@ -297,6 +297,7 @@ ExportArrowArrayPyCapsule(ImagingObject *self) {
 static PyObject *
 _new_arrow(PyObject *self, PyObject *args) {
     char *mode;
+    ModeID mode_id;
     int xsize, ysize;
     PyObject *schema_capsule, *array_capsule;
     PyObject *ret;
@@ -307,9 +308,11 @@ _new_arrow(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    mode_id = findModeID(mode);
+
     // ImagingBorrowArrow is responsible for retaining the array_capsule
     ret = PyImagingNew(
-        ImagingNewArrow(mode, xsize, ysize, schema_capsule, array_capsule)
+        ImagingNewArrow(mode_id, xsize, ysize, schema_capsule, array_capsule)
     );
     if (!ret) {
         return ImagingError_ValueError("Invalid Arrow array mode or size mismatch");
@@ -368,7 +371,7 @@ ImagingError_ValueError(const char *message) {
 /* -------------------------------------------------------------------- */
 
 static int
-getbands(const char *mode) {
+getbands(const ModeID mode) {
     Imaging im;
     int bands;
 
@@ -662,7 +665,7 @@ getink(PyObject *color, Imaging im, char *ink) {
             memcpy(ink, &ftmp, sizeof(ftmp));
             return ink;
         case IMAGING_TYPE_SPECIAL:
-            if (strncmp(im->mode, "I;16", 4) == 0) {
+            if (isModeI16(im->mode)) {
                 ink[0] = (UINT8)r;
                 ink[1] = (UINT8)(r >> 8);
                 ink[2] = ink[3] = 0;
@@ -694,7 +697,7 @@ getink(PyObject *color, Imaging im, char *ink) {
 
 static PyObject *
 _fill(PyObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
     int xsize, ysize;
     PyObject *color;
     char buffer[4];
@@ -703,10 +706,12 @@ _fill(PyObject *self, PyObject *args) {
     xsize = ysize = 256;
     color = NULL;
 
-    if (!PyArg_ParseTuple(args, "s|(ii)O", &mode, &xsize, &ysize, &color)) {
+    if (!PyArg_ParseTuple(args, "s|(ii)O", &mode_name, &xsize, &ysize, &color)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     im = ImagingNewDirty(mode, xsize, ysize);
     if (!im) {
         return NULL;
@@ -727,47 +732,55 @@ _fill(PyObject *self, PyObject *args) {
 
 static PyObject *
 _new(PyObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
     int xsize, ysize;
 
-    if (!PyArg_ParseTuple(args, "s(ii)", &mode, &xsize, &ysize)) {
+    if (!PyArg_ParseTuple(args, "s(ii)", &mode_name, &xsize, &ysize)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     return PyImagingNew(ImagingNew(mode, xsize, ysize));
 }
 
 static PyObject *
 _new_block(PyObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
     int xsize, ysize;
 
-    if (!PyArg_ParseTuple(args, "s(ii)", &mode, &xsize, &ysize)) {
+    if (!PyArg_ParseTuple(args, "s(ii)", &mode_name, &xsize, &ysize)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     return PyImagingNew(ImagingNewBlock(mode, xsize, ysize));
 }
 
 static PyObject *
 _linear_gradient(PyObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
 
-    if (!PyArg_ParseTuple(args, "s", &mode)) {
+    if (!PyArg_ParseTuple(args, "s", &mode_name)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     return PyImagingNew(ImagingFillLinearGradient(mode));
 }
 
 static PyObject *
 _radial_gradient(PyObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
 
-    if (!PyArg_ParseTuple(args, "s", &mode)) {
+    if (!PyArg_ParseTuple(args, "s", &mode_name)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     return PyImagingNew(ImagingFillRadialGradient(mode));
 }
 
@@ -907,7 +920,7 @@ _prepare_lut_table(PyObject *table, Py_ssize_t table_size) {
 
 static PyObject *
 _color_lut_3d(ImagingObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
     int filter;
     int table_channels;
     int size1D, size2D, size3D;
@@ -919,7 +932,7 @@ _color_lut_3d(ImagingObject *self, PyObject *args) {
     if (!PyArg_ParseTuple(
             args,
             "sii(iii)O:color_lut_3d",
-            &mode,
+            &mode_name,
             &filter,
             &table_channels,
             &size1D,
@@ -930,6 +943,8 @@ _color_lut_3d(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     /* actually, it is trilinear */
     if (filter != IMAGING_TRANSFORM_BILINEAR) {
         PyErr_SetString(PyExc_ValueError, "Only LINEAR filter is supported.");
@@ -976,11 +991,11 @@ _color_lut_3d(ImagingObject *self, PyObject *args) {
 
 static PyObject *
 _convert(ImagingObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
     int dither = 0;
     ImagingObject *paletteimage = NULL;
 
-    if (!PyArg_ParseTuple(args, "s|iO", &mode, &dither, &paletteimage)) {
+    if (!PyArg_ParseTuple(args, "s|iO", &mode_name, &dither, &paletteimage)) {
         return NULL;
     }
     if (paletteimage != NULL) {
@@ -997,6 +1012,8 @@ _convert(ImagingObject *self, PyObject *args) {
         }
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     return PyImagingNew(ImagingConvert(
         self->image, mode, paletteimage ? paletteimage->image->palette : NULL, dither
     ));
@@ -1021,14 +1038,14 @@ _convert2(ImagingObject *self, PyObject *args) {
 
 static PyObject *
 _convert_matrix(ImagingObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
     float m[12];
-    if (!PyArg_ParseTuple(args, "s(ffff)", &mode, m + 0, m + 1, m + 2, m + 3)) {
+    if (!PyArg_ParseTuple(args, "s(ffff)", &mode_name, m + 0, m + 1, m + 2, m + 3)) {
         PyErr_Clear();
         if (!PyArg_ParseTuple(
                 args,
                 "s(ffffffffffff)",
-                &mode,
+                &mode_name,
                 m + 0,
                 m + 1,
                 m + 2,
@@ -1046,18 +1063,22 @@ _convert_matrix(ImagingObject *self, PyObject *args) {
         }
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     return PyImagingNew(ImagingConvertMatrix(self->image, mode, m));
 }
 
 static PyObject *
 _convert_transparent(ImagingObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
     int r, g, b;
-    if (PyArg_ParseTuple(args, "s(iii)", &mode, &r, &g, &b)) {
+    if (PyArg_ParseTuple(args, "s(iii)", &mode_name, &r, &g, &b)) {
+        const ModeID mode = findModeID(mode_name);
         return PyImagingNew(ImagingConvertTransparent(self->image, mode, r, g, b));
     }
     PyErr_Clear();
-    if (PyArg_ParseTuple(args, "si", &mode, &r)) {
+    if (PyArg_ParseTuple(args, "si", &mode_name, &r)) {
+        const ModeID mode = findModeID(mode_name);
         return PyImagingNew(ImagingConvertTransparent(self->image, mode, r, 0, 0));
     }
     return NULL;
@@ -1156,9 +1177,9 @@ _getpalette(ImagingObject *self, PyObject *args) {
     int bits;
     ImagingShuffler pack;
 
-    char *mode = "RGB";
-    char *rawmode = "RGB";
-    if (!PyArg_ParseTuple(args, "|ss", &mode, &rawmode)) {
+    char *mode_name = "RGB";
+    char *rawmode_name = "RGB";
+    if (!PyArg_ParseTuple(args, "|ss", &mode_name, &rawmode_name)) {
         return NULL;
     }
 
@@ -1167,6 +1188,9 @@ _getpalette(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     pack = ImagingFindPacker(mode, rawmode, &bits);
     if (!pack) {
         PyErr_SetString(PyExc_ValueError, wrong_raw_mode);
@@ -1193,7 +1217,7 @@ _getpalettemode(ImagingObject *self) {
         return NULL;
     }
 
-    return PyUnicode_FromString(self->image->palette->mode);
+    return PyUnicode_FromString(getModeData(self->image->palette->mode)->name);
 }
 
 static inline int
@@ -1474,12 +1498,14 @@ _point(ImagingObject *self, PyObject *args) {
     Imaging im;
 
     PyObject *list;
-    char *mode;
-    if (!PyArg_ParseTuple(args, "Oz", &list, &mode)) {
+    char *mode_name;
+    if (!PyArg_ParseTuple(args, "Oz", &list, &mode_name)) {
         return NULL;
     }
 
-    if (mode && !strcmp(mode, "F")) {
+    const ModeID mode = findModeID(mode_name);
+
+    if (mode == IMAGING_MODE_F) {
         FLOAT32 *data;
 
         /* map from 8-bit data to floating point */
@@ -1490,8 +1516,7 @@ _point(ImagingObject *self, PyObject *args) {
         }
         im = ImagingPoint(self->image, mode, (void *)data);
         free(data);
-
-    } else if (!strcmp(self->image->mode, "I") && mode && !strcmp(mode, "L")) {
+    } else if (self->image->mode == IMAGING_MODE_I && mode == IMAGING_MODE_L) {
         UINT8 *data;
 
         /* map from 16-bit subset of 32-bit data to 8-bit */
@@ -1503,7 +1528,6 @@ _point(ImagingObject *self, PyObject *args) {
         }
         im = ImagingPoint(self->image, mode, (void *)data);
         free(data);
-
     } else {
         INT32 *data;
         UINT8 lut[1024];
@@ -1524,7 +1548,7 @@ _point(ImagingObject *self, PyObject *args) {
             return NULL;
         }
 
-        if (mode && !strcmp(mode, "I")) {
+        if (mode == IMAGING_MODE_I) {
             im = ImagingPoint(self->image, mode, (void *)data);
         } else if (mode && bands > 1) {
             for (i = 0; i < 256; i++) {
@@ -1630,9 +1654,9 @@ _putdata(ImagingObject *self, PyObject *args) {
             if (image->type == IMAGING_TYPE_SPECIAL) {
                 // I;16*
                 if (
-                    strcmp(image->mode, "I;16B") == 0
+                    image->mode == IMAGING_MODE_I_16B
 #ifdef WORDS_BIGENDIAN
-                    || strcmp(image->mode, "I;16N") == 0
+                    || image->mode == IMAGING_MODE_I_16N
 #endif
                 ) {
                     bigendian = 1;
@@ -1729,7 +1753,9 @@ _quantize(ImagingObject *self, PyObject *args) {
 
     if (!self->image->xsize || !self->image->ysize) {
         /* no content; return an empty image */
-        return PyImagingNew(ImagingNew("P", self->image->xsize, self->image->ysize));
+        return PyImagingNew(
+            ImagingNew(IMAGING_MODE_P, self->image->xsize, self->image->ysize)
+        );
     }
 
     return PyImagingNew(ImagingQuantize(self->image, colours, method, kmeans));
@@ -1740,21 +1766,33 @@ _putpalette(ImagingObject *self, PyObject *args) {
     ImagingShuffler unpack;
     int bits;
 
-    char *palette_mode, *rawmode;
+    char *palette_mode_name, *rawmode_name;
     UINT8 *palette;
     Py_ssize_t palettesize;
     if (!PyArg_ParseTuple(
-            args, "ssy#", &palette_mode, &rawmode, &palette, &palettesize
+            args, "ssy#", &palette_mode_name, &rawmode_name, &palette, &palettesize
         )) {
         return NULL;
     }
 
-    if (strcmp(self->image->mode, "L") && strcmp(self->image->mode, "LA") &&
-        strcmp(self->image->mode, "P") && strcmp(self->image->mode, "PA")) {
+    if (self->image->mode != IMAGING_MODE_L && self->image->mode != IMAGING_MODE_LA &&
+        self->image->mode != IMAGING_MODE_P && self->image->mode != IMAGING_MODE_PA) {
         PyErr_SetString(PyExc_ValueError, wrong_mode);
         return NULL;
     }
 
+    const ModeID palette_mode = findModeID(palette_mode_name);
+    if (palette_mode == IMAGING_MODE_UNKNOWN) {
+        PyErr_SetString(PyExc_ValueError, wrong_mode);
+        return NULL;
+    }
+
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+    if (rawmode == IMAGING_RAWMODE_UNKNOWN) {
+        PyErr_SetString(PyExc_ValueError, wrong_raw_mode);
+        return NULL;
+    }
+
     unpack = ImagingFindUnpacker(palette_mode, rawmode, &bits);
     if (!unpack) {
         PyErr_SetString(PyExc_ValueError, wrong_raw_mode);
@@ -1768,7 +1806,13 @@ _putpalette(ImagingObject *self, PyObject *args) {
 
     ImagingPaletteDelete(self->image->palette);
 
-    strcpy(self->image->mode, strlen(self->image->mode) == 2 ? "PA" : "P");
+    if (self->image->mode == IMAGING_MODE_LA) {
+        self->image->mode = IMAGING_MODE_PA;
+    } else if (self->image->mode == IMAGING_MODE_L) {
+        self->image->mode = IMAGING_MODE_P;
+    } else {
+        // The image already has a palette mode so we don't need to change it.
+    }
 
     self->image->palette = ImagingPaletteNew(palette_mode);
 
@@ -1796,7 +1840,7 @@ _putpalettealpha(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
-    strcpy(self->image->palette->mode, "RGBA");
+    self->image->palette->mode = IMAGING_MODE_RGBA;
     self->image->palette->palette[index * 4 + 3] = (UINT8)alpha;
 
     Py_RETURN_NONE;
@@ -1821,7 +1865,7 @@ _putpalettealphas(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
-    strcpy(self->image->palette->mode, "RGBA");
+    self->image->palette->mode = IMAGING_MODE_RGBA;
     for (i = 0; i < length; i++) {
         self->image->palette->palette[i * 4 + 3] = (UINT8)values[i];
     }
@@ -1989,8 +2033,11 @@ _reduce(ImagingObject *self, PyObject *args) {
     return PyImagingNew(imOut);
 }
 
-#define IS_RGB(mode) \
-    (!strcmp(mode, "RGB") || !strcmp(mode, "RGBA") || !strcmp(mode, "RGBX"))
+static int
+isRGB(const ModeID mode) {
+    return mode == IMAGING_MODE_RGB || mode == IMAGING_MODE_RGBA ||
+           mode == IMAGING_MODE_RGBX;
+}
 
 static PyObject *
 im_setmode(ImagingObject *self, PyObject *args) {
@@ -1998,23 +2045,25 @@ im_setmode(ImagingObject *self, PyObject *args) {
 
     Imaging im;
 
-    char *mode;
+    char *mode_name;
     Py_ssize_t modelen;
-    if (!PyArg_ParseTuple(args, "s#:setmode", &mode, &modelen)) {
+    if (!PyArg_ParseTuple(args, "s#:setmode", &mode_name, &modelen)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     im = self->image;
 
     /* move all logic in here to the libImaging primitive */
 
-    if (!strcmp(im->mode, mode)) {
+    if (im->mode == mode) {
         ; /* same mode; always succeeds */
-    } else if (IS_RGB(im->mode) && IS_RGB(mode)) {
+    } else if (isRGB(im->mode) && isRGB(mode)) {
         /* color to color */
-        strcpy(im->mode, mode);
+        im->mode = mode;
         im->bands = modelen;
-        if (!strcmp(mode, "RGBA")) {
+        if (mode == IMAGING_MODE_RGBA) {
             (void)ImagingFillBand(im, 3, 255);
         }
     } else {
@@ -2294,7 +2343,7 @@ _getextrema(ImagingObject *self) {
             case IMAGING_TYPE_FLOAT32:
                 return Py_BuildValue("dd", extrema.f[0], extrema.f[1]);
             case IMAGING_TYPE_SPECIAL:
-                if (strcmp(self->image->mode, "I;16") == 0) {
+                if (self->image->mode == IMAGING_MODE_I_16) {
                     return Py_BuildValue("HH", extrema.s[0], extrema.s[1]);
                 }
         }
@@ -2383,7 +2432,7 @@ _putband(ImagingObject *self, PyObject *args) {
 
 static PyObject *
 _merge(PyObject *self, PyObject *args) {
-    char *mode;
+    char *mode_name;
     ImagingObject *band0 = NULL;
     ImagingObject *band1 = NULL;
     ImagingObject *band2 = NULL;
@@ -2393,7 +2442,7 @@ _merge(PyObject *self, PyObject *args) {
     if (!PyArg_ParseTuple(
             args,
             "sO!|O!O!O!",
-            &mode,
+            &mode_name,
             &Imaging_Type,
             &band0,
             &Imaging_Type,
@@ -2406,6 +2455,8 @@ _merge(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+
     if (band0) {
         bands[0] = band0->image;
     }
@@ -2419,7 +2470,12 @@ _merge(PyObject *self, PyObject *args) {
         bands[3] = band3->image;
     }
 
-    return PyImagingNew(ImagingMerge(mode, bands));
+    Imaging imOut = ImagingMerge(mode, bands);
+    if (!imOut) {
+        return NULL;
+    }
+    ImagingCopyPalette(imOut, bands[0]);
+    return PyImagingNew(imOut);
 }
 
 static PyObject *
@@ -3711,7 +3767,7 @@ static struct PyMethodDef methods[] = {
 
 static PyObject *
 _getattr_mode(ImagingObject *self, void *closure) {
-    return PyUnicode_FromString(self->image->mode);
+    return PyUnicode_FromString(getModeData(self->image->mode)->name);
 }
 
 static PyObject *
@@ -4255,8 +4311,6 @@ setup_module(PyObject *m) {
         return -1;
     }
 
-    ImagingAccessInit();
-
 #ifdef HAVE_LIBJPEG
     {
         extern const char *ImagingJpegVersion(void);

src/_imagingcms.c

@@ -212,32 +212,44 @@ cms_transform_dealloc(CmsTransformObject *self) {
 /* internal functions */
 
 static cmsUInt32Number
-findLCMStype(char *PILmode) {
-    if (strcmp(PILmode, "RGB") == 0 || strcmp(PILmode, "RGBA") == 0 ||
-        strcmp(PILmode, "RGBX") == 0) {
+findLCMStype(const char *const mode_name) {
+    const ModeID mode = findModeID(mode_name);
+    switch (mode) {
+        case IMAGING_MODE_RGB:
+        case IMAGING_MODE_RGBA:
+        case IMAGING_MODE_RGBX:
             return TYPE_RGBA_8;
+        case IMAGING_MODE_CMYK:
+            return TYPE_CMYK_8;
+        case IMAGING_MODE_I_16:
+        case IMAGING_MODE_I_16L:
+            return TYPE_GRAY_16;
+        case IMAGING_MODE_I_16B:
+            return TYPE_GRAY_16_SE;
+        case IMAGING_MODE_YCbCr:
+            return TYPE_YCbCr_8;
+        case IMAGING_MODE_LAB:
+            // LabX equivalent like ALab, but not reversed -- no #define in lcms2
+            return (
+                COLORSPACE_SH(PT_LabV2) | CHANNELS_SH(3) | BYTES_SH(1) | EXTRA_SH(1)
+            );
+        default:
+            // This function only accepts a subset of the imaging modes Pillow has.
+            break;
     }
-    if (strcmp(PILmode, "RGBA;16B") == 0) {
+    // The following modes are not valid PIL Image modes.
+    if (strcmp(mode_name, "RGBA;16B") == 0) {
         return TYPE_RGBA_16;
     }
-    if (strcmp(PILmode, "CMYK") == 0) {
-        return TYPE_CMYK_8;
-    }
-    if (strcmp(PILmode, "I;16") == 0 || strcmp(PILmode, "I;16L") == 0 ||
-        strcmp(PILmode, "L;16") == 0) {
+    if (strcmp(mode_name, "L;16") == 0) {
         return TYPE_GRAY_16;
     }
-    if (strcmp(PILmode, "I;16B") == 0 || strcmp(PILmode, "L;16B") == 0) {
+    if (strcmp(mode_name, "L;16B") == 0) {
         return TYPE_GRAY_16_SE;
     }
-    if (strcmp(PILmode, "YCbCr") == 0 || strcmp(PILmode, "YCCA") == 0 ||
-        strcmp(PILmode, "YCC") == 0) {
+    if (strcmp(mode_name, "YCCA") == 0 || strcmp(mode_name, "YCC") == 0) {
         return TYPE_YCbCr_8;
     }
-    if (strcmp(PILmode, "LAB") == 0) {
-        // LabX equivalent like ALab, but not reversed -- no #define in lcms2
-        return (COLORSPACE_SH(PT_LabV2) | CHANNELS_SH(3) | BYTES_SH(1) | EXTRA_SH(1));
-    }
     /* presume "1" or "L" by default */
     return TYPE_GRAY_8;
 }

src/_imagingft.c

@@ -525,7 +525,7 @@ font_getlength(FontObject *self, PyObject *args) {
     int horizontal_dir;           /* is primary axis horizontal? */
     int mask = 0;                 /* is FT_LOAD_TARGET_MONO enabled? */
     int color = 0;                /* is FT_LOAD_COLOR enabled? */
-    const char *mode = NULL;
+    const char *mode_name = NULL;
     const char *dir = NULL;
     const char *lang = NULL;
     PyObject *features = Py_None;
@@ -534,15 +534,16 @@ font_getlength(FontObject *self, PyObject *args) {
     /* calculate size and bearing for a given string */
 
     if (!PyArg_ParseTuple(
-            args, "O|zzOz:getlength", &string, &mode, &dir, &features, &lang
+            args, "O|zzOz:getlength", &string, &mode_name, &dir, &features, &lang
         )) {
         return NULL;
     }
 
     horizontal_dir = dir && strcmp(dir, "ttb") == 0 ? 0 : 1;
 
-    mask = mode && strcmp(mode, "1") == 0;
-    color = mode && strcmp(mode, "RGBA") == 0;
+    const ModeID mode = findModeID(mode_name);
+    mask = mode == IMAGING_MODE_1;
+    color = mode == IMAGING_MODE_RGBA;
 
     count = text_layout(string, self, dir, features, lang, &glyph_info, mask, color);
     if (PyErr_Occurred()) {
@@ -754,7 +755,7 @@ font_getsize(FontObject *self, PyObject *args) {
     int horizontal_dir;           /* is primary axis horizontal? */
     int mask = 0;                 /* is FT_LOAD_TARGET_MONO enabled? */
     int color = 0;                /* is FT_LOAD_COLOR enabled? */
-    const char *mode = NULL;
+    const char *mode_name = NULL;
     const char *dir = NULL;
     const char *lang = NULL;
     const char *anchor = NULL;
@@ -764,15 +765,23 @@ font_getsize(FontObject *self, PyObject *args) {
     /* calculate size and bearing for a given string */
 
     if (!PyArg_ParseTuple(
-            args, "O|zzOzz:getsize", &string, &mode, &dir, &features, &lang, &anchor
+            args,
+            "O|zzOzz:getsize",
+            &string,
+            &mode_name,
+            &dir,
+            &features,
+            &lang,
+            &anchor
         )) {
         return NULL;
     }
 
     horizontal_dir = dir && strcmp(dir, "ttb") == 0 ? 0 : 1;
 
-    mask = mode && strcmp(mode, "1") == 0;
-    color = mode && strcmp(mode, "RGBA") == 0;
+    const ModeID mode = findModeID(mode_name);
+    mask = mode == IMAGING_MODE_1;
+    color = mode == IMAGING_MODE_RGBA;
 
     count = text_layout(string, self, dir, features, lang, &glyph_info, mask, color);
     if (PyErr_Occurred()) {
@@ -839,7 +848,7 @@ font_render(FontObject *self, PyObject *args) {
     int stroke_filled = 0;
     PY_LONG_LONG foreground_ink_long = 0;
     unsigned int foreground_ink;
-    const char *mode = NULL;
+    const char *mode_name = NULL;
     const char *dir = NULL;
     const char *lang = NULL;
     const char *anchor = NULL;
@@ -859,7 +868,7 @@ font_render(FontObject *self, PyObject *args) {
             "OO|zzOzfpzL(ff):render",
             &string,
             &fill,
-            &mode,
+            &mode_name,
             &dir,
             &features,
             &lang,
@@ -873,8 +882,9 @@ font_render(FontObject *self, PyObject *args) {
         return NULL;
     }
 
-    mask = mode && strcmp(mode, "1") == 0;
-    color = mode && strcmp(mode, "RGBA") == 0;
+    const ModeID mode = findModeID(mode_name);
+    mask = mode == IMAGING_MODE_1;
+    color = mode == IMAGING_MODE_RGBA;
 
     foreground_ink = foreground_ink_long;
 

src/_webp.c

@@ -89,8 +89,8 @@ HandleMuxError(WebPMuxError err, char *chunk) {
 
 static int
 import_frame_libwebp(WebPPicture *frame, Imaging im) {
-    if (strcmp(im->mode, "RGBA") && strcmp(im->mode, "RGB") &&
-        strcmp(im->mode, "RGBX")) {
+    if (im->mode != IMAGING_MODE_RGBA && im->mode != IMAGING_MODE_RGB &&
+        im->mode != IMAGING_MODE_RGBX) {
         PyErr_SetString(PyExc_ValueError, "unsupported image mode");
         return -1;
     }
@@ -104,7 +104,7 @@ import_frame_libwebp(WebPPicture *frame, Imaging im) {
         return -2;
     }
 
-    int ignore_fourth_channel = strcmp(im->mode, "RGBA");
+    int ignore_fourth_channel = im->mode != IMAGING_MODE_RGBA;
     for (int y = 0; y < im->ysize; ++y) {
         UINT8 *src = (UINT8 *)im->image32[y];
         UINT32 *dst = frame->argb + frame->argb_stride * y;
@@ -143,7 +143,7 @@ typedef struct {
     PyObject_HEAD WebPAnimDecoder *dec;
     WebPAnimInfo info;
     WebPData data;
-    char *mode;
+    ModeID mode;
 } WebPAnimDecoderObject;
 
 static PyTypeObject WebPAnimDecoder_Type;
@@ -396,7 +396,7 @@ _anim_decoder_new(PyObject *self, PyObject *args) {
     const uint8_t *webp;
     Py_ssize_t size;
     WebPData webp_src;
-    char *mode;
+    ModeID mode;
     WebPDecoderConfig config;
     WebPAnimDecoderObject *decp = NULL;
     WebPAnimDecoder *dec = NULL;
@@ -409,10 +409,10 @@ _anim_decoder_new(PyObject *self, PyObject *args) {
     webp_src.size = size;
 
     // Sniff the mode, since the decoder API doesn't tell us
-    mode = "RGBA";
+    mode = IMAGING_MODE_RGBA;
     if (WebPGetFeatures(webp, size, &config.input) == VP8_STATUS_OK) {
         if (!config.input.has_alpha) {
-            mode = "RGBX";
+            mode = IMAGING_MODE_RGBX;
         }
     }
 
@@ -455,7 +455,7 @@ _anim_decoder_get_info(PyObject *self) {
         info->loop_count,
         info->bgcolor,
         info->frame_count,
-        decp->mode
+        getModeData(decp->mode)->name
     );
 }
 

src/decode.c

@@ -266,7 +266,9 @@ static PyTypeObject ImagingDecoderType = {
 /* -------------------------------------------------------------------- */
 
 int
-get_unpacker(ImagingDecoderObject *decoder, const char *mode, const char *rawmode) {
+get_unpacker(
+    ImagingDecoderObject *decoder, const ModeID mode, const RawModeID rawmode
+) {
     int bits;
     ImagingShuffler unpack;
 
@@ -291,17 +293,20 @@ PyObject *
 PyImaging_BitDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
+    const char *mode_name;
     int bits = 8;
     int pad = 8;
     int fill = 0;
     int sign = 0;
     int ystep = 1;
-    if (!PyArg_ParseTuple(args, "s|iiiii", &mode, &bits, &pad, &fill, &sign, &ystep)) {
+    if (!PyArg_ParseTuple(
+            args, "s|iiiii", &mode_name, &bits, &pad, &fill, &sign, &ystep
+        )) {
         return NULL;
     }
 
-    if (strcmp(mode, "F") != 0) {
+    const ModeID mode = findModeID(mode_name);
+    if (mode != IMAGING_MODE_F) {
         PyErr_SetString(PyExc_ValueError, "bad image mode");
         return NULL;
     }
@@ -331,34 +336,36 @@ PyObject *
 PyImaging_BcnDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *actual;
+    char *mode_name;
     int n = 0;
     char *pixel_format = "";
-    if (!PyArg_ParseTuple(args, "si|s", &mode, &n, &pixel_format)) {
+    if (!PyArg_ParseTuple(args, "si|s", &mode_name, &n, &pixel_format)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    ModeID actual;
+
     switch (n) {
         case 1: /* BC1: 565 color, 1-bit alpha */
         case 2: /* BC2: 565 color, 4-bit alpha */
         case 3: /* BC3: 565 color, 2-endpoint 8-bit interpolated alpha */
         case 7: /* BC7: 4-channel 8-bit via everything */
-            actual = "RGBA";
+            actual = IMAGING_MODE_RGBA;
             break;
         case 4: /* BC4: 1-channel 8-bit via 1 BC3 alpha block */
-            actual = "L";
+            actual = IMAGING_MODE_L;
             break;
         case 5: /* BC5: 2-channel 8-bit via 2 BC3 alpha blocks */
         case 6: /* BC6: 3-channel 16-bit float */
-            actual = "RGB";
+            actual = IMAGING_MODE_RGB;
             break;
         default:
             PyErr_SetString(PyExc_ValueError, "block compression type unknown");
             return NULL;
     }
 
-    if (strcmp(mode, actual) != 0) {
+    if (mode != actual) {
         PyErr_SetString(PyExc_ValueError, "bad image mode");
         return NULL;
     }
@@ -401,15 +408,18 @@ PyObject *
 PyImaging_GifDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
+    const char *mode_name;
     int bits = 8;
     int interlace = 0;
     int transparency = -1;
-    if (!PyArg_ParseTuple(args, "s|iii", &mode, &bits, &interlace, &transparency)) {
+    if (!PyArg_ParseTuple(
+            args, "s|iii", &mode_name, &bits, &interlace, &transparency
+        )) {
         return NULL;
     }
 
-    if (strcmp(mode, "L") != 0 && strcmp(mode, "P") != 0) {
+    const ModeID mode = findModeID(mode_name);
+    if (mode != IMAGING_MODE_L && mode != IMAGING_MODE_P) {
         PyErr_SetString(PyExc_ValueError, "bad image mode");
         return NULL;
     }
@@ -436,12 +446,14 @@ PyObject *
 PyImaging_HexDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;
-    if (!PyArg_ParseTuple(args, "ss", &mode, &rawmode)) {
+    char *mode_name, *rawmode_name;
+    if (!PyArg_ParseTuple(args, "ss", &mode_name, &rawmode_name)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     decoder = PyImaging_DecoderNew(0);
     if (decoder == NULL) {
         return NULL;
@@ -469,16 +481,21 @@ PyImaging_HexDecoderNew(PyObject *self, PyObject *args) {
 PyObject *
 PyImaging_LibTiffDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
-    char *mode;
-    char *rawmode;
+    char *mode_name;
+    char *rawmode_name;
     char *compname;
     int fp;
     uint32_t ifdoffset;
 
-    if (!PyArg_ParseTuple(args, "sssiI", &mode, &rawmode, &compname, &fp, &ifdoffset)) {
+    if (!PyArg_ParseTuple(
+            args, "sssiI", &mode_name, &rawmode_name, &compname, &fp, &ifdoffset
+        )) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     TRACE(("new tiff decoder %s\n", compname));
 
     decoder = PyImaging_DecoderNew(sizeof(TIFFSTATE));
@@ -511,12 +528,15 @@ PyObject *
 PyImaging_PackbitsDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;
-    if (!PyArg_ParseTuple(args, "ss", &mode, &rawmode)) {
+    char *mode_name;
+    char *rawmode_name;
+    if (!PyArg_ParseTuple(args, "ss", &mode_name, &rawmode_name)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     decoder = PyImaging_DecoderNew(0);
     if (decoder == NULL) {
         return NULL;
@@ -545,7 +565,7 @@ PyImaging_PcdDecoderNew(PyObject *self, PyObject *args) {
     }
 
     /* Unpack from PhotoYCC to RGB */
-    if (get_unpacker(decoder, "RGB", "YCC;P") < 0) {
+    if (get_unpacker(decoder, IMAGING_MODE_RGB, IMAGING_RAWMODE_YCC_P) < 0) {
         return NULL;
     }
 
@@ -562,13 +582,15 @@ PyObject *
 PyImaging_PcxDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name, *rawmode_name;
     int stride;
-    if (!PyArg_ParseTuple(args, "ssi", &mode, &rawmode, &stride)) {
+    if (!PyArg_ParseTuple(args, "ssi", &mode_name, &rawmode_name, &stride)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     decoder = PyImaging_DecoderNew(0);
     if (decoder == NULL) {
         return NULL;
@@ -593,14 +615,16 @@ PyObject *
 PyImaging_RawDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name, *rawmode_name;
     int stride = 0;
     int ystep = 1;
-    if (!PyArg_ParseTuple(args, "ss|ii", &mode, &rawmode, &stride, &ystep)) {
+    if (!PyArg_ParseTuple(args, "ss|ii", &mode_name, &rawmode_name, &stride, &ystep)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     decoder = PyImaging_DecoderNew(sizeof(RAWSTATE));
     if (decoder == NULL) {
         return NULL;
@@ -627,14 +651,16 @@ PyObject *
 PyImaging_SgiRleDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name, *rawmode_name;
     int ystep = 1;
     int bpc = 1;
-    if (!PyArg_ParseTuple(args, "ss|ii", &mode, &rawmode, &ystep, &bpc)) {
+    if (!PyArg_ParseTuple(args, "ss|ii", &mode_name, &rawmode_name, &ystep, &bpc)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     decoder = PyImaging_DecoderNew(sizeof(SGISTATE));
     if (decoder == NULL) {
         return NULL;
@@ -661,12 +687,14 @@ PyObject *
 PyImaging_SunRleDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;
-    if (!PyArg_ParseTuple(args, "ss", &mode, &rawmode)) {
+    char *mode_name, *rawmode_name;
+    if (!PyArg_ParseTuple(args, "ss", &mode_name, &rawmode_name)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     decoder = PyImaging_DecoderNew(0);
     if (decoder == NULL) {
         return NULL;
@@ -689,14 +717,16 @@ PyObject *
 PyImaging_TgaRleDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name, *rawmode_name;
     int ystep = 1;
     int depth = 8;
-    if (!PyArg_ParseTuple(args, "ss|ii", &mode, &rawmode, &ystep, &depth)) {
+    if (!PyArg_ParseTuple(args, "ss|ii", &mode_name, &rawmode_name, &ystep, &depth)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     decoder = PyImaging_DecoderNew(0);
     if (decoder == NULL) {
         return NULL;
@@ -727,7 +757,7 @@ PyImaging_XbmDecoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
-    if (get_unpacker(decoder, "1", "1;R") < 0) {
+    if (get_unpacker(decoder, IMAGING_MODE_1, IMAGING_RAWMODE_1_R) < 0) {
         return NULL;
     }
 
@@ -748,13 +778,15 @@ PyObject *
 PyImaging_ZipDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name, *rawmode_name;
     int interlaced = 0;
-    if (!PyArg_ParseTuple(args, "ss|i", &mode, &rawmode, &interlaced)) {
+    if (!PyArg_ParseTuple(args, "ss|i", &mode_name, &rawmode_name, &interlaced)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     decoder = PyImaging_DecoderNew(sizeof(ZIPSTATE));
     if (decoder == NULL) {
         return NULL;
@@ -798,19 +830,21 @@ PyObject *
 PyImaging_JpegDecoderNew(PyObject *self, PyObject *args) {
     ImagingDecoderObject *decoder;
 
-    char *mode;
-    char *rawmode;  /* what we want from the decoder */
-    char *jpegmode; /* what's in the file */
+    char *mode_name;
+    char *rawmode_name;  /* what we want from the decoder */
+    char *jpegmode_name; /* what's in the file */
     int scale = 1;
     int draft = 0;
 
-    if (!PyArg_ParseTuple(args, "ssz|ii", &mode, &rawmode, &jpegmode, &scale, &draft)) {
+    if (!PyArg_ParseTuple(
+            args, "ssz|ii", &mode_name, &rawmode_name, &jpegmode_name, &scale, &draft
+        )) {
         return NULL;
     }
 
-    if (!jpegmode) {
-        jpegmode = "";
-    }
+    const ModeID mode = findModeID(mode_name);
+    RawModeID rawmode = findRawModeID(rawmode_name);
+    const RawModeID jpegmode = findRawModeID(jpegmode_name);
 
     decoder = PyImaging_DecoderNew(sizeof(JPEGSTATE));
     if (decoder == NULL) {
@@ -820,8 +854,8 @@ PyImaging_JpegDecoderNew(PyObject *self, PyObject *args) {
     // libjpeg-turbo supports different output formats.
     // We are choosing Pillow's native format (3 color bytes + 1 padding)
     // to avoid extra conversion in Unpack.c.
-    if (ImagingJpegUseJCSExtensions() && strcmp(rawmode, "RGB") == 0) {
-        rawmode = "RGBX";
+    if (ImagingJpegUseJCSExtensions() && rawmode == IMAGING_RAWMODE_RGB) {
+        rawmode = IMAGING_RAWMODE_RGBX;
     }
 
     if (get_unpacker(decoder, mode, rawmode) < 0) {
@@ -831,11 +865,13 @@ PyImaging_JpegDecoderNew(PyObject *self, PyObject *args) {
     decoder->decode = ImagingJpegDecode;
     decoder->cleanup = ImagingJpegDecodeCleanup;
 
-    strncpy(((JPEGSTATE *)decoder->state.context)->rawmode, rawmode, 8);
-    strncpy(((JPEGSTATE *)decoder->state.context)->jpegmode, jpegmode, 8);
+    JPEGSTATE *jpeg_decoder_state_context = (JPEGSTATE *)decoder->state.context;
 
-    ((JPEGSTATE *)decoder->state.context)->scale = scale;
-    ((JPEGSTATE *)decoder->state.context)->draft = draft;
+    jpeg_decoder_state_context->rawmode = rawmode;
+    jpeg_decoder_state_context->jpegmode = jpegmode;
+
+    jpeg_decoder_state_context->scale = scale;
+    jpeg_decoder_state_context->draft = draft;
 
     return (PyObject *)decoder;
 }

src/display.c

@@ -47,7 +47,7 @@ typedef struct {
 static PyTypeObject ImagingDisplayType;
 
 static ImagingDisplayObject *
-_new(const char *mode, int xsize, int ysize) {
+_new(const ModeID mode, int xsize, int ysize) {
     ImagingDisplayObject *display;
 
     if (PyType_Ready(&ImagingDisplayType) < 0) {
@@ -235,7 +235,7 @@ static struct PyMethodDef methods[] = {
 
 static PyObject *
 _getattr_mode(ImagingDisplayObject *self, void *closure) {
-    return Py_BuildValue("s", self->dib->mode);
+    return Py_BuildValue("s", getModeData(self->dib->mode)->name);
 }
 
 static PyObject *
@@ -258,13 +258,14 @@ static PyTypeObject ImagingDisplayType = {
 PyObject *
 PyImaging_DisplayWin32(PyObject *self, PyObject *args) {
     ImagingDisplayObject *display;
-    char *mode;
+    char *mode_name;
     int xsize, ysize;
 
-    if (!PyArg_ParseTuple(args, "s(ii)", &mode, &xsize, &ysize)) {
+    if (!PyArg_ParseTuple(args, "s(ii)", &mode_name, &xsize, &ysize)) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
     display = _new(mode, xsize, ysize);
     if (display == NULL) {
         return NULL;
@@ -275,12 +276,9 @@ PyImaging_DisplayWin32(PyObject *self, PyObject *args) {
 
 PyObject *
 PyImaging_DisplayModeWin32(PyObject *self, PyObject *args) {
-    char *mode;
     int size[2];
-
-    mode = ImagingGetModeDIB(size);
-
-    return Py_BuildValue("s(ii)", mode, size[0], size[1]);
+    const ModeID mode = ImagingGetModeDIB(size);
+    return Py_BuildValue("s(ii)", getModeData(mode)->name, size[0], size[1]);
 }
 
 /* -------------------------------------------------------------------- */

src/encode.c

@@ -334,14 +334,19 @@ static PyTypeObject ImagingEncoderType = {
 /* -------------------------------------------------------------------- */
 
 int
-get_packer(ImagingEncoderObject *encoder, const char *mode, const char *rawmode) {
+get_packer(ImagingEncoderObject *encoder, const ModeID mode, const RawModeID rawmode) {
     int bits;
     ImagingShuffler pack;
 
     pack = ImagingFindPacker(mode, rawmode, &bits);
     if (!pack) {
         Py_DECREF(encoder);
-        PyErr_Format(PyExc_ValueError, "No packer found from %s to %s", mode, rawmode);
+        PyErr_Format(
+            PyExc_ValueError,
+            "No packer found from %s to %s",
+            getModeData(mode)->name,
+            getRawModeData(rawmode)->name
+        );
         return -1;
     }
 
@@ -402,11 +407,13 @@ PyObject *
 PyImaging_GifEncoderNew(PyObject *self, PyObject *args) {
     ImagingEncoderObject *encoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name;
+    char *rawmode_name;
     Py_ssize_t bits = 8;
     Py_ssize_t interlace = 0;
-    if (!PyArg_ParseTuple(args, "ss|nn", &mode, &rawmode, &bits, &interlace)) {
+    if (!PyArg_ParseTuple(
+            args, "ss|nn", &mode_name, &rawmode_name, &bits, &interlace
+        )) {
         return NULL;
     }
 
@@ -415,6 +422,9 @@ PyImaging_GifEncoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     if (get_packer(encoder, mode, rawmode) < 0) {
         return NULL;
     }
@@ -435,11 +445,11 @@ PyObject *
 PyImaging_PcxEncoderNew(PyObject *self, PyObject *args) {
     ImagingEncoderObject *encoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name;
+    char *rawmode_name;
     Py_ssize_t bits = 8;
 
-    if (!PyArg_ParseTuple(args, "ss|n", &mode, &rawmode, &bits)) {
+    if (!PyArg_ParseTuple(args, "ss|n", &mode_name, &rawmode_name, &bits)) {
         return NULL;
     }
 
@@ -448,6 +458,9 @@ PyImaging_PcxEncoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     if (get_packer(encoder, mode, rawmode) < 0) {
         return NULL;
     }
@@ -465,12 +478,12 @@ PyObject *
 PyImaging_RawEncoderNew(PyObject *self, PyObject *args) {
     ImagingEncoderObject *encoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name;
+    char *rawmode_name;
     Py_ssize_t stride = 0;
     Py_ssize_t ystep = 1;
 
-    if (!PyArg_ParseTuple(args, "ss|nn", &mode, &rawmode, &stride, &ystep)) {
+    if (!PyArg_ParseTuple(args, "ss|nn", &mode_name, &rawmode_name, &stride, &ystep)) {
         return NULL;
     }
 
@@ -479,6 +492,9 @@ PyImaging_RawEncoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     if (get_packer(encoder, mode, rawmode) < 0) {
         return NULL;
     }
@@ -499,11 +515,11 @@ PyObject *
 PyImaging_TgaRleEncoderNew(PyObject *self, PyObject *args) {
     ImagingEncoderObject *encoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name;
+    char *rawmode_name;
     Py_ssize_t ystep = 1;
 
-    if (!PyArg_ParseTuple(args, "ss|n", &mode, &rawmode, &ystep)) {
+    if (!PyArg_ParseTuple(args, "ss|n", &mode_name, &rawmode_name, &ystep)) {
         return NULL;
     }
 
@@ -512,6 +528,9 @@ PyImaging_TgaRleEncoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     if (get_packer(encoder, mode, rawmode) < 0) {
         return NULL;
     }
@@ -536,7 +555,7 @@ PyImaging_XbmEncoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
-    if (get_packer(encoder, "1", "1;R") < 0) {
+    if (get_packer(encoder, IMAGING_MODE_1, IMAGING_RAWMODE_1_R) < 0) {
         return NULL;
     }
 
@@ -557,8 +576,8 @@ PyObject *
 PyImaging_ZipEncoderNew(PyObject *self, PyObject *args) {
     ImagingEncoderObject *encoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name;
+    char *rawmode_name;
     Py_ssize_t optimize = 0;
     Py_ssize_t compress_level = -1;
     Py_ssize_t compress_type = -1;
@@ -567,8 +586,8 @@ PyImaging_ZipEncoderNew(PyObject *self, PyObject *args) {
     if (!PyArg_ParseTuple(
             args,
             "ss|nnny#",
-            &mode,
-            &rawmode,
+            &mode_name,
+            &rawmode_name,
             &optimize,
             &compress_level,
             &compress_type,
@@ -597,6 +616,9 @@ PyImaging_ZipEncoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     if (get_packer(encoder, mode, rawmode) < 0) {
         free(dictionary);
         return NULL;
@@ -605,7 +627,7 @@ PyImaging_ZipEncoderNew(PyObject *self, PyObject *args) {
     encoder->encode = ImagingZipEncode;
     encoder->cleanup = ImagingZipEncodeCleanup;
 
-    if (rawmode[0] == 'P') {
+    if (rawmode == IMAGING_RAWMODE_P || rawmode == IMAGING_RAWMODE_PA) {
         /* disable filtering */
         ((ZIPSTATE *)encoder->state.context)->mode = ZIP_PNG_PALETTE;
     }
@@ -634,8 +656,8 @@ PyObject *
 PyImaging_LibTiffEncoderNew(PyObject *self, PyObject *args) {
     ImagingEncoderObject *encoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name;
+    char *rawmode_name;
     char *compname;
     char *filename;
     Py_ssize_t fp;
@@ -655,7 +677,15 @@ PyImaging_LibTiffEncoderNew(PyObject *self, PyObject *args) {
     PyObject *item;
 
     if (!PyArg_ParseTuple(
-            args, "sssnsOO", &mode, &rawmode, &compname, &fp, &filename, &tags, &types
+            args,
+            "sssnsOO",
+            &mode_name,
+            &rawmode_name,
+            &compname,
+            &fp,
+            &filename,
+            &tags,
+            &types
         )) {
         return NULL;
     }
@@ -693,6 +723,9 @@ PyImaging_LibTiffEncoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    const RawModeID rawmode = findRawModeID(rawmode_name);
+
     if (get_packer(encoder, mode, rawmode) < 0) {
         return NULL;
     }
@@ -922,6 +955,18 @@ PyImaging_LibTiffEncoderNew(PyObject *self, PyObject *args) {
                     );
                     free(av);
                 }
+            } else if (type == TIFF_RATIONAL) {
+                FLOAT32 *av;
+                /* malloc check ok, calloc checks for overflow */
+                av = calloc(len, sizeof(FLOAT32));
+                if (av) {
+                    for (i = 0; i < len; i++) {
+                        av[i] = (FLOAT32)PyFloat_AsDouble(PyTuple_GetItem(value, i));
+                    }
+                    status =
+                        ImagingLibTiffSetField(&encoder->state, (ttag_t)key_int, av);
+                    free(av);
+                }
             }
         } else {
             if (type == TIFF_SHORT) {
@@ -1076,8 +1121,8 @@ PyObject *
 PyImaging_JpegEncoderNew(PyObject *self, PyObject *args) {
     ImagingEncoderObject *encoder;
 
-    char *mode;
-    char *rawmode;
+    char *mode_name;
+    char *rawmode_name;
     Py_ssize_t quality = 0;
     Py_ssize_t progressive = 0;
     Py_ssize_t smooth = 0;
@@ -1101,8 +1146,8 @@ PyImaging_JpegEncoderNew(PyObject *self, PyObject *args) {
     if (!PyArg_ParseTuple(
             args,
             "ss|nnnnpn(nn)nnnOz#y#y#",
-            &mode,
-            &rawmode,
+            &mode_name,
+            &rawmode_name,
             &quality,
             &progressive,
             &smooth,
@@ -1130,11 +1175,14 @@ PyImaging_JpegEncoderNew(PyObject *self, PyObject *args) {
         return NULL;
     }
 
+    const ModeID mode = findModeID(mode_name);
+    RawModeID rawmode = findRawModeID(rawmode_name);
+
     // libjpeg-turbo supports different output formats.
     // We are choosing Pillow's native format (3 color bytes + 1 padding)
     // to avoid extra conversion in Pack.c.
-    if (ImagingJpegUseJCSExtensions() && strcmp(rawmode, "RGB") == 0) {
-        rawmode = "RGBX";
+    if (ImagingJpegUseJCSExtensions() && rawmode == IMAGING_RAWMODE_RGB) {
+        rawmode = IMAGING_RAWMODE_RGBX;
     }
 
     if (get_packer(encoder, mode, rawmode) < 0) {
@@ -1192,7 +1240,7 @@ PyImaging_JpegEncoderNew(PyObject *self, PyObject *args) {
     encoder->encode = ImagingJpegEncode;
 
     JPEGENCODERSTATE *jpeg_encoder_state = (JPEGENCODERSTATE *)encoder->state.context;
-    strncpy(jpeg_encoder_state->rawmode, rawmode, 8);
+    jpeg_encoder_state->rawmode = rawmode;
     jpeg_encoder_state->keep_rgb = keep_rgb;
     jpeg_encoder_state->quality = quality;
     jpeg_encoder_state->qtables = qarrays;

src/libImaging/Access.c

@@ -11,39 +11,6 @@
 
 #include "Imaging.h"
 
-/* use make_hash.py from the pillow-scripts repository to calculate these values */
-#define ACCESS_TABLE_SIZE 35
-#define ACCESS_TABLE_HASH 8940
-
-static struct ImagingAccessInstance access_table[ACCESS_TABLE_SIZE];
-
-static inline UINT32
-hash(const char *mode) {
-    UINT32 i = ACCESS_TABLE_HASH;
-    while (*mode) {
-        i = ((i << 5) + i) ^ (UINT8)*mode++;
-    }
-    return i % ACCESS_TABLE_SIZE;
-}
-
-static ImagingAccess
-add_item(const char *mode) {
-    UINT32 i = hash(mode);
-    /* printf("hash %s => %d\n", mode, i); */
-    if (access_table[i].mode && strcmp(access_table[i].mode, mode) != 0) {
-        fprintf(
-            stderr,
-            "AccessInit: hash collision: %d for both %s and %s\n",
-            i,
-            mode,
-            access_table[i].mode
-        );
-        exit(1);
-    }
-    access_table[i].mode = mode;
-    return &access_table[i];
-}
-
 /* fetch individual pixel */
 
 static void
@@ -64,7 +31,7 @@ static void
 get_pixel_16L(Imaging im, int x, int y, void *color) {
     UINT8 *in = (UINT8 *)&im->image[y][x + x];
 #ifdef WORDS_BIGENDIAN
-    UINT16 out = in[0] + (in[1] << 8);
+    UINT16 out = in[0] + ((UINT16)in[1] << 8);
     memcpy(color, &out, sizeof(out));
 #else
     memcpy(color, in, sizeof(UINT16));
@@ -77,7 +44,7 @@ get_pixel_16B(Imaging im, int x, int y, void *color) {
 #ifdef WORDS_BIGENDIAN
     memcpy(color, in, sizeof(UINT16));
 #else
-    UINT16 out = in[1] + (in[0] << 8);
+    UINT16 out = in[1] + ((UINT16)in[0] << 8);
     memcpy(color, &out, sizeof(out));
 #endif
 }
@@ -87,28 +54,6 @@ get_pixel_32(Imaging im, int x, int y, void *color) {
     memcpy(color, &im->image32[y][x], sizeof(INT32));
 }
 
-static void
-get_pixel_32L(Imaging im, int x, int y, void *color) {
-    UINT8 *in = (UINT8 *)&im->image[y][x * 4];
-#ifdef WORDS_BIGENDIAN
-    INT32 out = in[0] + (in[1] << 8) + (in[2] << 16) + (in[3] << 24);
-    memcpy(color, &out, sizeof(out));
-#else
-    memcpy(color, in, sizeof(INT32));
-#endif
-}
-
-static void
-get_pixel_32B(Imaging im, int x, int y, void *color) {
-    UINT8 *in = (UINT8 *)&im->image[y][x * 4];
-#ifdef WORDS_BIGENDIAN
-    memcpy(color, in, sizeof(INT32));
-#else
-    INT32 out = in[3] + (in[2] << 8) + (in[1] << 16) + (in[0] << 24);
-    memcpy(color, &out, sizeof(out));
-#endif
-}
-
 /* store individual pixel */
 
 static void
@@ -129,71 +74,46 @@ put_pixel_16B(Imaging im, int x, int y, const void *color) {
     out[1] = in[0];
 }
 
-static void
-put_pixel_32L(Imaging im, int x, int y, const void *color) {
-    memcpy(&im->image8[y][x * 4], color, 4);
-}
-
-static void
-put_pixel_32B(Imaging im, int x, int y, const void *color) {
-    const char *in = color;
-    UINT8 *out = (UINT8 *)&im->image8[y][x * 4];
-    out[0] = in[3];
-    out[1] = in[2];
-    out[2] = in[1];
-    out[3] = in[0];
-}
-
 static void
 put_pixel_32(Imaging im, int x, int y, const void *color) {
     memcpy(&im->image32[y][x], color, sizeof(INT32));
 }
 
-void
-ImagingAccessInit(void) {
-#define ADD(mode_, get_pixel_, put_pixel_)      \
-    {                                           \
-        ImagingAccess access = add_item(mode_); \
-        access->get_pixel = get_pixel_;         \
-        access->put_pixel = put_pixel_;         \
-    }
-
-    /* populate access table */
-    ADD("1", get_pixel_8, put_pixel_8);
-    ADD("L", get_pixel_8, put_pixel_8);
-    ADD("LA", get_pixel_32_2bands, put_pixel_32);
-    ADD("La", get_pixel_32_2bands, put_pixel_32);
-    ADD("I", get_pixel_32, put_pixel_32);
-    ADD("I;16", get_pixel_16L, put_pixel_16L);
-    ADD("I;16L", get_pixel_16L, put_pixel_16L);
-    ADD("I;16B", get_pixel_16B, put_pixel_16B);
+static struct ImagingAccessInstance accessors[] = {
+    {IMAGING_MODE_1, get_pixel_8, put_pixel_8},
+    {IMAGING_MODE_L, get_pixel_8, put_pixel_8},
+    {IMAGING_MODE_LA, get_pixel_32_2bands, put_pixel_32},
+    {IMAGING_MODE_La, get_pixel_32_2bands, put_pixel_32},
+    {IMAGING_MODE_I, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_I_16, get_pixel_16L, put_pixel_16L},
+    {IMAGING_MODE_I_16L, get_pixel_16L, put_pixel_16L},
+    {IMAGING_MODE_I_16B, get_pixel_16B, put_pixel_16B},
 #ifdef WORDS_BIGENDIAN
-    ADD("I;16N", get_pixel_16B, put_pixel_16B);
+    {IMAGING_MODE_I_16N, get_pixel_16B, put_pixel_16B},
 #else
-    ADD("I;16N", get_pixel_16L, put_pixel_16L);
+    {IMAGING_MODE_I_16N, get_pixel_16L, put_pixel_16L},
 #endif
-    ADD("I;32L", get_pixel_32L, put_pixel_32L);
-    ADD("I;32B", get_pixel_32B, put_pixel_32B);
-    ADD("F", get_pixel_32, put_pixel_32);
-    ADD("P", get_pixel_8, put_pixel_8);
-    ADD("PA", get_pixel_32_2bands, put_pixel_32);
-    ADD("RGB", get_pixel_32, put_pixel_32);
-    ADD("RGBA", get_pixel_32, put_pixel_32);
-    ADD("RGBa", get_pixel_32, put_pixel_32);
-    ADD("RGBX", get_pixel_32, put_pixel_32);
-    ADD("CMYK", get_pixel_32, put_pixel_32);
-    ADD("YCbCr", get_pixel_32, put_pixel_32);
-    ADD("LAB", get_pixel_32, put_pixel_32);
-    ADD("HSV", get_pixel_32, put_pixel_32);
-}
+    {IMAGING_MODE_F, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_P, get_pixel_8, put_pixel_8},
+    {IMAGING_MODE_PA, get_pixel_32_2bands, put_pixel_32},
+    {IMAGING_MODE_RGB, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_RGBA, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_RGBa, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_RGBX, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_CMYK, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_YCbCr, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_LAB, get_pixel_32, put_pixel_32},
+    {IMAGING_MODE_HSV, get_pixel_32, put_pixel_32},
+};
 
 ImagingAccess
-ImagingAccessNew(Imaging im) {
-    ImagingAccess access = &access_table[hash(im->mode)];
-    if (im->mode[0] != access->mode[0] || strcmp(im->mode, access->mode) != 0) {
-        return NULL;
+ImagingAccessNew(const Imaging im) {
+    for (size_t i = 0; i < sizeof(accessors) / sizeof(*accessors); i++) {
+        if (im->mode == accessors[i].mode) {
+            return &accessors[i];
         }
-    return access;
+    }
+    return NULL;
 }
 
 void

src/libImaging/AlphaComposite.c

@@ -26,11 +26,11 @@ ImagingAlphaComposite(Imaging imDst, Imaging imSrc) {
 
     /* Check arguments */
     if (!imDst || !imSrc ||
-        (strcmp(imDst->mode, "RGBA") && strcmp(imDst->mode, "LA"))) {
+        (imDst->mode != IMAGING_MODE_RGBA && imDst->mode != IMAGING_MODE_LA)) {
         return ImagingError_ModeError();
     }
 
-    if (strcmp(imDst->mode, imSrc->mode) || imDst->xsize != imSrc->xsize ||
+    if (imDst->mode != imSrc->mode || imDst->xsize != imSrc->xsize ||
         imDst->ysize != imSrc->ysize) {
         return ImagingError_Mismatch();
     }

src/libImaging/Arrow.c

@@ -55,6 +55,98 @@ ReleaseExportedSchema(struct ArrowSchema *array) {
     // Mark array released
     array->release = NULL;
 }
+char *
+image_band_json(Imaging im) {
+    char *format = "{\"bands\": [\"%s\", \"%s\", \"%s\", \"%s\"]}";
+    char *json;
+    // Bands can be 4 bands * 2 characters each
+    int len = strlen(format) + 8 + 1;
+    int err;
+
+    json = calloc(1, len);
+
+    if (!json) {
+        return NULL;
+    }
+
+    err = PyOS_snprintf(
+        json,
+        len,
+        format,
+        im->band_names[0],
+        im->band_names[1],
+        im->band_names[2],
+        im->band_names[3]
+    );
+    if (err < 0) {
+        return NULL;
+    }
+    return json;
+}
+
+char *
+single_band_json(Imaging im) {
+    char *format = "{\"bands\": [\"%s\"]}";
+    char *json;
+    // Bands can be 1 band * (maybe but probably not) 2 characters each
+    int len = strlen(format) + 2 + 1;
+    int err;
+
+    json = calloc(1, len);
+
+    if (!json) {
+        return NULL;
+    }
+
+    err = PyOS_snprintf(json, len, format, im->band_names[0]);
+    if (err < 0) {
+        return NULL;
+    }
+    return json;
+}
+
+char *
+assemble_metadata(const char *band_json) {
+    /* format is
+       int32: number of key/value pairs (noted N below)
+       int32: byte length of key 0
+       key 0 (not null-terminated)
+       int32: byte length of value 0
+       value 0 (not null-terminated)
+       ...
+       int32: byte length of key N - 1
+       key N - 1 (not null-terminated)
+       int32: byte length of value N - 1
+       value N - 1 (not null-terminated)
+    */
+    const char *key = "image";
+    INT32 key_len = strlen(key);
+    INT32 band_json_len = strlen(band_json);
+
+    char *buf;
+    INT32 *dest_int;
+    char *dest;
+
+    buf = calloc(1, key_len + band_json_len + 4 + 1 * 8);
+    if (!buf) {
+        return NULL;
+    }
+
+    dest_int = (void *)buf;
+
+    dest_int[0] = 1;
+    dest_int[1] = key_len;
+    dest_int += 2;
+    dest = (void *)dest_int;
+    memcpy(dest, key, key_len);
+    dest += key_len;
+    dest_int = (void *)dest;
+    dest_int[0] = band_json_len;
+    dest_int += 1;
+    memcpy(dest_int, band_json, band_json_len);
+
+    return buf;
+}
 
 int
 export_named_type(struct ArrowSchema *schema, char *format, char *name) {
@@ -95,6 +187,7 @@ export_named_type(struct ArrowSchema *schema, char *format, char *name) {
 int
 export_imaging_schema(Imaging im, struct ArrowSchema *schema) {
     int retval = 0;
+    char *band_json;
 
     if (strcmp(im->arrow_band_format, "") == 0) {
         return IMAGING_ARROW_INCOMPATIBLE_MODE;
@@ -106,7 +199,17 @@ export_imaging_schema(Imaging im, struct ArrowSchema *schema) {
     }
 
     if (im->bands == 1) {
-        return export_named_type(schema, im->arrow_band_format, im->band_names[0]);
+        retval = export_named_type(schema, im->arrow_band_format, im->band_names[0]);
+        if (retval != 0) {
+            return retval;
+        }
+        // band related metadata
+        band_json = single_band_json(im);
+        if (band_json) {
+            schema->metadata = assemble_metadata(band_json);
+            free(band_json);
+        }
+        return retval;
     }
 
     retval = export_named_type(schema, "+w:4", "");
@@ -117,13 +220,26 @@ export_imaging_schema(Imaging im, struct ArrowSchema *schema) {
     schema->n_children = 1;
     schema->children = calloc(1, sizeof(struct ArrowSchema *));
     schema->children[0] = (struct ArrowSchema *)calloc(1, sizeof(struct ArrowSchema));
-    retval = export_named_type(schema->children[0], im->arrow_band_format, "pixel");
+    retval = export_named_type(
+        schema->children[0], im->arrow_band_format, getModeData(im->mode)->name
+    );
     if (retval != 0) {
         free(schema->children[0]);
         free(schema->children);
         schema->release(schema);
         return retval;
     }
+
+    // band related metadata
+    band_json = image_band_json(im);
+    if (band_json) {
+        // adding the metadata to the child array.
+        // Accessible in pyarrow via pa.array(img).type.field(0).metadata
+        // adding it to the top level is not accessible.
+        schema->children[0]->metadata = assemble_metadata(band_json);
+        free(band_json);
+    }
+
     return 0;
 }
 

src/libImaging/Bands.c

@@ -41,7 +41,7 @@ ImagingGetBand(Imaging imIn, int band) {
         band = 3;
     }
 
-    imOut = ImagingNewDirty("L", imIn->xsize, imIn->ysize);
+    imOut = ImagingNewDirty(IMAGING_MODE_L, imIn->xsize, imIn->ysize);
     if (!imOut) {
         return NULL;
     }
@@ -82,7 +82,7 @@ ImagingSplit(Imaging imIn, Imaging bands[4]) {
     }
 
     for (i = 0; i < imIn->bands; i++) {
-        bands[i] = ImagingNewDirty("L", imIn->xsize, imIn->ysize);
+        bands[i] = ImagingNewDirty(IMAGING_MODE_L, imIn->xsize, imIn->ysize);
         if (!bands[i]) {
             for (j = 0; j < i; ++j) {
                 ImagingDelete(bands[j]);
@@ -240,7 +240,7 @@ ImagingFillBand(Imaging imOut, int band, int color) {
 }
 
 Imaging
-ImagingMerge(const char *mode, Imaging bands[4]) {
+ImagingMerge(const ModeID mode, Imaging bands[4]) {
     int i, x, y;
     int bandsCount = 0;
     Imaging imOut;

src/libImaging/BcnDecode.c

@@ -603,7 +603,7 @@ static void
 bc6_sign_extend(UINT16 *v, int prec) {
     int x = *v;
     if (x & (1 << (prec - 1))) {
-        x |= -1 << prec;
+        x |= -(1 << prec);
     }
     *v = (UINT16)x;
 }

src/libImaging/BcnEncode.c

@@ -36,10 +36,9 @@ decode_565(UINT16 x) {
 
 static UINT16
 encode_565(rgba item) {
-    UINT8 r, g, b;
-    r = item.color[0] >> (8 - 5);
-    g = item.color[1] >> (8 - 6);
-    b = item.color[2] >> (8 - 5);
+    UINT16 r = item.color[0] >> (8 - 5);
+    UINT8 g = item.color[1] >> (8 - 6);
+    UINT8 b = item.color[2] >> (8 - 5);
     return (r << (5 + 6)) | (g << 5) | b;
 }
 
@@ -157,7 +156,8 @@ encode_bc1_color(Imaging im, ImagingCodecState state, UINT8 *dst, int separate_a
 static void
 encode_bc2_block(Imaging im, ImagingCodecState state, UINT8 *dst) {
     int i, j;
-    UINT8 block[16], current_alpha;
+    UINT8 block[16];
+    UINT32 current_alpha;
     for (i = 0; i < 4; i++) {
         for (j = 0; j < 4; j++) {
             int x = state->x + i * im->pixelsize;
@@ -253,7 +253,7 @@ int
 ImagingBcnEncode(Imaging im, ImagingCodecState state, UINT8 *buf, int bytes) {
     int n = state->state;
     int has_alpha_channel =
-        strcmp(im->mode, "RGBA") == 0 || strcmp(im->mode, "LA") == 0;
+        im->mode == IMAGING_MODE_RGBA || im->mode == IMAGING_MODE_LA;
 
     UINT8 *dst = buf;
 

src/libImaging/Blend.c

@@ -24,8 +24,8 @@ ImagingBlend(Imaging imIn1, Imaging imIn2, float alpha) {
 
     /* Check arguments */
     if (!imIn1 || !imIn2 || imIn1->type != IMAGING_TYPE_UINT8 || imIn1->palette ||
-        strcmp(imIn1->mode, "1") == 0 || imIn2->palette ||
-        strcmp(imIn2->mode, "1") == 0) {
+        imIn1->mode == IMAGING_MODE_1 || imIn2->palette ||
+        imIn2->mode == IMAGING_MODE_1) {
         return ImagingError_ModeError();
     }
 

src/libImaging/BoxBlur.c

@@ -248,7 +248,7 @@ ImagingBoxBlur(Imaging imOut, Imaging imIn, float xradius, float yradius, int n)
         return ImagingError_ValueError("radius must be >= 0");
     }
 
-    if (strcmp(imIn->mode, imOut->mode) || imIn->type != imOut->type ||
+    if (imIn->mode != imOut->mode || imIn->type != imOut->type ||
         imIn->bands != imOut->bands || imIn->xsize != imOut->xsize ||
         imIn->ysize != imOut->ysize) {
         return ImagingError_Mismatch();
@@ -258,10 +258,10 @@ ImagingBoxBlur(Imaging imOut, Imaging imIn, float xradius, float yradius, int n)
         return ImagingError_ModeError();
     }
 
-    if (!(strcmp(imIn->mode, "RGB") == 0 || strcmp(imIn->mode, "RGBA") == 0 ||
-          strcmp(imIn->mode, "RGBa") == 0 || strcmp(imIn->mode, "RGBX") == 0 ||
-          strcmp(imIn->mode, "CMYK") == 0 || strcmp(imIn->mode, "L") == 0 ||
-          strcmp(imIn->mode, "LA") == 0 || strcmp(imIn->mode, "La") == 0)) {
+    if (imIn->mode != IMAGING_MODE_RGB && imIn->mode != IMAGING_MODE_RGBA &&
+        imIn->mode != IMAGING_MODE_RGBa && imIn->mode != IMAGING_MODE_RGBX &&
+        imIn->mode != IMAGING_MODE_CMYK && imIn->mode != IMAGING_MODE_L &&
+        imIn->mode != IMAGING_MODE_LA && imIn->mode != IMAGING_MODE_La) {
         return ImagingError_ModeError();
     }
 

src/libImaging/Chops.c

@@ -21,7 +21,7 @@
 #define CHOP(operation)                                 \
     int x, y;                                           \
     Imaging imOut;                                      \
-    imOut = create(imIn1, imIn2, NULL);         \
+    imOut = create(imIn1, imIn2, IMAGING_MODE_UNKNOWN); \
     if (!imOut) {                                       \
         return NULL;                                    \
     }                                                   \
@@ -60,11 +60,12 @@
     return imOut;
 
 static Imaging
-create(Imaging im1, Imaging im2, char *mode) {
+create(Imaging im1, Imaging im2, const ModeID mode) {
     int xsize, ysize;
 
     if (!im1 || !im2 || im1->type != IMAGING_TYPE_UINT8 ||
-        (mode != NULL && (strcmp(im1->mode, "1") || strcmp(im2->mode, "1")))) {
+        (mode != IMAGING_MODE_UNKNOWN &&
+         (im1->mode != IMAGING_MODE_1 || im2->mode != IMAGING_MODE_1))) {
         return (Imaging)ImagingError_ModeError();
     }
     if (im1->type != im2->type || im1->bands != im2->bands) {
@@ -114,27 +115,27 @@ ImagingChopSubtract(Imaging imIn1, Imaging imIn2, float scale, int offset) {
 
 Imaging
 ImagingChopAnd(Imaging imIn1, Imaging imIn2) {
-    CHOP2((in1[x] && in2[x]) ? 255 : 0, "1");
+    CHOP2((in1[x] && in2[x]) ? 255 : 0, IMAGING_MODE_1);
 }
 
 Imaging
 ImagingChopOr(Imaging imIn1, Imaging imIn2) {
-    CHOP2((in1[x] || in2[x]) ? 255 : 0, "1");
+    CHOP2((in1[x] || in2[x]) ? 255 : 0, IMAGING_MODE_1);
 }
 
 Imaging
 ImagingChopXor(Imaging imIn1, Imaging imIn2) {
-    CHOP2(((in1[x] != 0) ^ (in2[x] != 0)) ? 255 : 0, "1");
+    CHOP2(((in1[x] != 0) ^ (in2[x] != 0)) ? 255 : 0, IMAGING_MODE_1);
 }
 
 Imaging
 ImagingChopAddModulo(Imaging imIn1, Imaging imIn2) {
-    CHOP2(in1[x] + in2[x], NULL);
+    CHOP2(in1[x] + in2[x], IMAGING_MODE_UNKNOWN);
 }
 
 Imaging
 ImagingChopSubtractModulo(Imaging imIn1, Imaging imIn2) {
-    CHOP2(in1[x] - in2[x], NULL);
+    CHOP2(in1[x] - in2[x], IMAGING_MODE_UNKNOWN);
 }
 
 Imaging
@@ -142,7 +143,7 @@ ImagingChopSoftLight(Imaging imIn1, Imaging imIn2) {
     CHOP2(
         (((255 - in1[x]) * (in1[x] * in2[x])) / 65536) +
             (in1[x] * (255 - ((255 - in1[x]) * (255 - in2[x]) / 255))) / 255,
-        NULL
+        IMAGING_MODE_UNKNOWN
     );
 }
 
@@ -151,7 +152,7 @@ ImagingChopHardLight(Imaging imIn1, Imaging imIn2) {
     CHOP2(
         (in2[x] < 128) ? ((in1[x] * in2[x]) / 127)
                        : 255 - (((255 - in2[x]) * (255 - in1[x])) / 127),
-        NULL
+        IMAGING_MODE_UNKNOWN
     );
 }
 
@@ -160,6 +161,6 @@ ImagingOverlay(Imaging imIn1, Imaging imIn2) {
     CHOP2(
         (in1[x] < 128) ? ((in1[x] * in2[x]) / 127)
                        : 255 - (((255 - in1[x]) * (255 - in2[x])) / 127),
-        NULL
+        IMAGING_MODE_UNKNOWN
     );
 }

src/libImaging/Convert.c

@@ -877,147 +877,12 @@ I16_RGB(UINT8 *out, const UINT8 *in, int xsize) {
     }
 }
 
-static struct {
-    const char *from;
-    const char *to;
-    ImagingShuffler convert;
-} converters[] = {
-
-    {"1", "L", bit2l},
-    {"1", "I", bit2i},
-    {"1", "F", bit2f},
-    {"1", "RGB", bit2rgb},
-    {"1", "RGBA", bit2rgb},
-    {"1", "RGBX", bit2rgb},
-    {"1", "CMYK", bit2cmyk},
-    {"1", "YCbCr", bit2ycbcr},
-    {"1", "HSV", bit2hsv},
-
-    {"L", "1", l2bit},
-    {"L", "LA", l2la},
-    {"L", "I", l2i},
-    {"L", "F", l2f},
-    {"L", "RGB", l2rgb},
-    {"L", "RGBA", l2rgb},
-    {"L", "RGBX", l2rgb},
-    {"L", "CMYK", l2cmyk},
-    {"L", "YCbCr", l2ycbcr},
-    {"L", "HSV", l2hsv},
-
-    {"LA", "L", la2l},
-    {"LA", "La", lA2la},
-    {"LA", "RGB", la2rgb},
-    {"LA", "RGBA", la2rgb},
-    {"LA", "RGBX", la2rgb},
-    {"LA", "CMYK", la2cmyk},
-    {"LA", "YCbCr", la2ycbcr},
-    {"LA", "HSV", la2hsv},
-
-    {"La", "LA", la2lA},
-
-    {"I", "L", i2l},
-    {"I", "F", i2f},
-    {"I", "RGB", i2rgb},
-    {"I", "RGBA", i2rgb},
-    {"I", "RGBX", i2rgb},
-    {"I", "HSV", i2hsv},
-
-    {"F", "L", f2l},
-    {"F", "I", f2i},
-
-    {"RGB", "1", rgb2bit},
-    {"RGB", "L", rgb2l},
-    {"RGB", "LA", rgb2la},
-    {"RGB", "La", rgb2la},
-    {"RGB", "I", rgb2i},
-    {"RGB", "I;16", rgb2i16l},
-    {"RGB", "I;16L", rgb2i16l},
-    {"RGB", "I;16B", rgb2i16b},
-#ifdef WORDS_BIGENDIAN
-    {"RGB", "I;16N", rgb2i16b},
-#else
-    {"RGB", "I;16N", rgb2i16l},
-#endif
-    {"RGB", "F", rgb2f},
-    {"RGB", "RGBA", rgb2rgba},
-    {"RGB", "RGBa", rgb2rgba},
-    {"RGB", "RGBX", rgb2rgba},
-    {"RGB", "CMYK", rgb2cmyk},
-    {"RGB", "YCbCr", ImagingConvertRGB2YCbCr},
-    {"RGB", "HSV", rgb2hsv},
-
-    {"RGBA", "1", rgb2bit},
-    {"RGBA", "L", rgb2l},
-    {"RGBA", "LA", rgba2la},
-    {"RGBA", "I", rgb2i},
-    {"RGBA", "F", rgb2f},
-    {"RGBA", "RGB", rgba2rgb},
-    {"RGBA", "RGBa", rgbA2rgba},
-    {"RGBA", "RGBX", rgb2rgba},
-    {"RGBA", "CMYK", rgb2cmyk},
-    {"RGBA", "YCbCr", ImagingConvertRGB2YCbCr},
-    {"RGBA", "HSV", rgb2hsv},
-
-    {"RGBa", "RGBA", rgba2rgbA},
-    {"RGBa", "RGB", rgba2rgb_},
-
-    {"RGBX", "1", rgb2bit},
-    {"RGBX", "L", rgb2l},
-    {"RGBX", "LA", rgb2la},
-    {"RGBX", "I", rgb2i},
-    {"RGBX", "F", rgb2f},
-    {"RGBX", "RGB", rgba2rgb},
-    {"RGBX", "CMYK", rgb2cmyk},
-    {"RGBX", "YCbCr", ImagingConvertRGB2YCbCr},
-    {"RGBX", "HSV", rgb2hsv},
-
-    {"CMYK", "RGB", cmyk2rgb},
-    {"CMYK", "RGBA", cmyk2rgb},
-    {"CMYK", "RGBX", cmyk2rgb},
-    {"CMYK", "HSV", cmyk2hsv},
-
-    {"YCbCr", "L", ycbcr2l},
-    {"YCbCr", "LA", ycbcr2la},
-    {"YCbCr", "RGB", ImagingConvertYCbCr2RGB},
-
-    {"HSV", "RGB", hsv2rgb},
-
-    {"I", "I;16", I_I16L},
-    {"I;16", "I", I16L_I},
-    {"I;16", "RGB", I16_RGB},
-    {"L", "I;16", L_I16L},
-    {"I;16", "L", I16L_L},
-
-    {"I", "I;16L", I_I16L},
-    {"I;16L", "I", I16L_I},
-    {"I", "I;16B", I_I16B},
-    {"I;16B", "I", I16B_I},
-
-    {"L", "I;16L", L_I16L},
-    {"I;16L", "L", I16L_L},
-    {"L", "I;16B", L_I16B},
-    {"I;16B", "L", I16B_L},
-#ifdef WORDS_BIGENDIAN
-    {"L", "I;16N", L_I16B},
-    {"I;16N", "L", I16B_L},
-#else
-    {"L", "I;16N", L_I16L},
-    {"I;16N", "L", I16L_L},
-#endif
-
-    {"I;16", "F", I16L_F},
-    {"I;16L", "F", I16L_F},
-    {"I;16B", "F", I16B_F},
-
-    {NULL}
-};
-
-/* FIXME: translate indexed versions to pointer versions below this line */
-
 /* ------------------- */
 /* Palette conversions */
 /* ------------------- */
 
+/* FIXME: translate indexed versions to pointer versions below this line */
+
 static void
 p2bit(UINT8 *out, const UINT8 *in, int xsize, ImagingPalette palette) {
     int x;
@@ -1065,13 +930,13 @@ pa2p(UINT8 *out, const UINT8 *in, int xsize, ImagingPalette palette) {
 static void
 p2pa(UINT8 *out, const UINT8 *in, int xsize, ImagingPalette palette) {
     int x;
-    int rgb = strcmp(palette->mode, "RGB");
+    const int rgb = palette->mode == IMAGING_MODE_RGB;
     for (x = 0; x < xsize; x++, in++) {
         const UINT8 *rgba = &palette->palette[in[0] * 4];
         *out++ = in[0];
         *out++ = in[0];
         *out++ = in[0];
-        *out++ = rgb == 0 ? 255 : rgba[3];
+        *out++ = rgb ? 255 : rgba[3];
     }
 }
 
@@ -1225,7 +1090,7 @@ pa2ycbcr(UINT8 *out, const UINT8 *in, int xsize, ImagingPalette palette) {
 }
 
 static Imaging
-frompalette(Imaging imOut, Imaging imIn, const char *mode) {
+frompalette(Imaging imOut, Imaging imIn, const ModeID mode) {
     ImagingSectionCookie cookie;
     int alpha;
     int y;
@@ -1237,31 +1102,31 @@ frompalette(Imaging imOut, Imaging imIn, const char *mode) {
         return (Imaging)ImagingError_ValueError("no palette");
     }
 
-    alpha = !strcmp(imIn->mode, "PA");
+    alpha = imIn->mode == IMAGING_MODE_PA;
 
-    if (strcmp(mode, "1") == 0) {
+    if (mode == IMAGING_MODE_1) {
         convert = alpha ? pa2bit : p2bit;
-    } else if (strcmp(mode, "L") == 0) {
+    } else if (mode == IMAGING_MODE_L) {
         convert = alpha ? pa2l : p2l;
-    } else if (strcmp(mode, "LA") == 0) {
+    } else if (mode == IMAGING_MODE_LA) {
         convert = alpha ? pa2la : p2la;
-    } else if (strcmp(mode, "P") == 0) {
+    } else if (mode == IMAGING_MODE_P) {
         convert = pa2p;
-    } else if (strcmp(mode, "PA") == 0) {
+    } else if (mode == IMAGING_MODE_PA) {
         convert = p2pa;
-    } else if (strcmp(mode, "I") == 0) {
+    } else if (mode == IMAGING_MODE_I) {
         convert = alpha ? pa2i : p2i;
-    } else if (strcmp(mode, "F") == 0) {
+    } else if (mode == IMAGING_MODE_F) {
         convert = alpha ? pa2f : p2f;
-    } else if (strcmp(mode, "RGB") == 0) {
+    } else if (mode == IMAGING_MODE_RGB) {
         convert = alpha ? pa2rgb : p2rgb;
-    } else if (strcmp(mode, "RGBA") == 0 || strcmp(mode, "RGBX") == 0) {
+    } else if (mode == IMAGING_MODE_RGBA || mode == IMAGING_MODE_RGBX) {
         convert = alpha ? pa2rgba : p2rgba;
-    } else if (strcmp(mode, "CMYK") == 0) {
+    } else if (mode == IMAGING_MODE_CMYK) {
         convert = alpha ? pa2cmyk : p2cmyk;
-    } else if (strcmp(mode, "YCbCr") == 0) {
+    } else if (mode == IMAGING_MODE_YCbCr) {
         convert = alpha ? pa2ycbcr : p2ycbcr;
-    } else if (strcmp(mode, "HSV") == 0) {
+    } else if (mode == IMAGING_MODE_HSV) {
         convert = alpha ? pa2hsv : p2hsv;
     } else {
         return (Imaging)ImagingError_ValueError("conversion not supported");
@@ -1271,7 +1136,7 @@ frompalette(Imaging imOut, Imaging imIn, const char *mode) {
     if (!imOut) {
         return NULL;
     }
-    if (strcmp(mode, "P") == 0 || strcmp(mode, "PA") == 0) {
+    if (mode == IMAGING_MODE_P || mode == IMAGING_MODE_PA) {
         ImagingPaletteDelete(imOut->palette);
         imOut->palette = ImagingPaletteDuplicate(imIn->palette);
     }
@@ -1295,24 +1160,26 @@ frompalette(Imaging imOut, Imaging imIn, const char *mode) {
 #endif
 static Imaging
 topalette(
-    Imaging imOut, Imaging imIn, const char *mode, ImagingPalette inpalette, int dither
+    Imaging imOut, Imaging imIn, const ModeID mode, ImagingPalette inpalette, int dither
 ) {
     ImagingSectionCookie cookie;
     int alpha;
     int x, y;
     ImagingPalette palette = inpalette;
 
-    /* Map L or RGB/RGBX/RGBA to palette image */
-    if (strcmp(imIn->mode, "L") != 0 && strncmp(imIn->mode, "RGB", 3) != 0) {
+    /* Map L or RGB/RGBX/RGBA/RGBa to palette image */
+    if (imIn->mode != IMAGING_MODE_L && imIn->mode != IMAGING_MODE_RGB &&
+        imIn->mode != IMAGING_MODE_RGBX && imIn->mode != IMAGING_MODE_RGBA &&
+        imIn->mode != IMAGING_MODE_RGBa) {
         return (Imaging)ImagingError_ValueError("conversion not supported");
     }
 
-    alpha = !strcmp(mode, "PA");
+    alpha = mode == IMAGING_MODE_PA;
 
     if (palette == NULL) {
         /* FIXME: make user configurable */
         if (imIn->bands == 1) {
-            palette = ImagingPaletteNew("RGB");
+            palette = ImagingPaletteNew(IMAGING_MODE_RGB);
 
             palette->size = 256;
             int i;
@@ -1499,11 +1366,11 @@ tobilevel(Imaging imOut, Imaging imIn) {
     int *errors;
 
     /* Map L or RGB to dithered 1 image */
-    if (strcmp(imIn->mode, "L") != 0 && strcmp(imIn->mode, "RGB") != 0) {
+    if (imIn->mode != IMAGING_MODE_L && imIn->mode != IMAGING_MODE_RGB) {
         return (Imaging)ImagingError_ValueError("conversion not supported");
     }
 
-    imOut = ImagingNew2Dirty("1", imOut, imIn);
+    imOut = ImagingNew2Dirty(IMAGING_MODE_1, imOut, imIn);
     if (!imOut) {
         return NULL;
     }
@@ -1585,19 +1452,152 @@ tobilevel(Imaging imOut, Imaging imIn) {
 #pragma optimize("", on)
 #endif
 
+/* ------------------- */
+/* Conversion handlers */
+/* ------------------- */
+
+static struct {
+    const ModeID from;
+    const ModeID to;
+    ImagingShuffler convert;
+} converters[] = {
+    {IMAGING_MODE_1, IMAGING_MODE_L, bit2l},
+    {IMAGING_MODE_1, IMAGING_MODE_I, bit2i},
+    {IMAGING_MODE_1, IMAGING_MODE_F, bit2f},
+    {IMAGING_MODE_1, IMAGING_MODE_RGB, bit2rgb},
+    {IMAGING_MODE_1, IMAGING_MODE_RGBA, bit2rgb},
+    {IMAGING_MODE_1, IMAGING_MODE_RGBX, bit2rgb},
+    {IMAGING_MODE_1, IMAGING_MODE_CMYK, bit2cmyk},
+    {IMAGING_MODE_1, IMAGING_MODE_YCbCr, bit2ycbcr},
+    {IMAGING_MODE_1, IMAGING_MODE_HSV, bit2hsv},
+
+    {IMAGING_MODE_L, IMAGING_MODE_1, l2bit},
+    {IMAGING_MODE_L, IMAGING_MODE_LA, l2la},
+    {IMAGING_MODE_L, IMAGING_MODE_I, l2i},
+    {IMAGING_MODE_L, IMAGING_MODE_F, l2f},
+    {IMAGING_MODE_L, IMAGING_MODE_RGB, l2rgb},
+    {IMAGING_MODE_L, IMAGING_MODE_RGBA, l2rgb},
+    {IMAGING_MODE_L, IMAGING_MODE_RGBX, l2rgb},
+    {IMAGING_MODE_L, IMAGING_MODE_CMYK, l2cmyk},
+    {IMAGING_MODE_L, IMAGING_MODE_YCbCr, l2ycbcr},
+    {IMAGING_MODE_L, IMAGING_MODE_HSV, l2hsv},
+
+    {IMAGING_MODE_LA, IMAGING_MODE_L, la2l},
+    {IMAGING_MODE_LA, IMAGING_MODE_La, lA2la},
+    {IMAGING_MODE_LA, IMAGING_MODE_RGB, la2rgb},
+    {IMAGING_MODE_LA, IMAGING_MODE_RGBA, la2rgb},
+    {IMAGING_MODE_LA, IMAGING_MODE_RGBX, la2rgb},
+    {IMAGING_MODE_LA, IMAGING_MODE_CMYK, la2cmyk},
+    {IMAGING_MODE_LA, IMAGING_MODE_YCbCr, la2ycbcr},
+    {IMAGING_MODE_LA, IMAGING_MODE_HSV, la2hsv},
+
+    {IMAGING_MODE_La, IMAGING_MODE_LA, la2lA},
+
+    {IMAGING_MODE_I, IMAGING_MODE_L, i2l},
+    {IMAGING_MODE_I, IMAGING_MODE_F, i2f},
+    {IMAGING_MODE_I, IMAGING_MODE_RGB, i2rgb},
+    {IMAGING_MODE_I, IMAGING_MODE_RGBA, i2rgb},
+    {IMAGING_MODE_I, IMAGING_MODE_RGBX, i2rgb},
+    {IMAGING_MODE_I, IMAGING_MODE_HSV, i2hsv},
+
+    {IMAGING_MODE_F, IMAGING_MODE_L, f2l},
+    {IMAGING_MODE_F, IMAGING_MODE_I, f2i},
+
+    {IMAGING_MODE_RGB, IMAGING_MODE_1, rgb2bit},
+    {IMAGING_MODE_RGB, IMAGING_MODE_L, rgb2l},
+    {IMAGING_MODE_RGB, IMAGING_MODE_LA, rgb2la},
+    {IMAGING_MODE_RGB, IMAGING_MODE_La, rgb2la},
+    {IMAGING_MODE_RGB, IMAGING_MODE_I, rgb2i},
+    {IMAGING_MODE_RGB, IMAGING_MODE_I_16, rgb2i16l},
+    {IMAGING_MODE_RGB, IMAGING_MODE_I_16L, rgb2i16l},
+    {IMAGING_MODE_RGB, IMAGING_MODE_I_16B, rgb2i16b},
+#ifdef WORDS_BIGENDIAN
+    {IMAGING_MODE_RGB, IMAGING_MODE_I_16N, rgb2i16b},
+#else
+    {IMAGING_MODE_RGB, IMAGING_MODE_I_16N, rgb2i16l},
+#endif
+    {IMAGING_MODE_RGB, IMAGING_MODE_F, rgb2f},
+    {IMAGING_MODE_RGB, IMAGING_MODE_RGBA, rgb2rgba},
+    {IMAGING_MODE_RGB, IMAGING_MODE_RGBa, rgb2rgba},
+    {IMAGING_MODE_RGB, IMAGING_MODE_RGBX, rgb2rgba},
+    {IMAGING_MODE_RGB, IMAGING_MODE_CMYK, rgb2cmyk},
+    {IMAGING_MODE_RGB, IMAGING_MODE_YCbCr, ImagingConvertRGB2YCbCr},
+    {IMAGING_MODE_RGB, IMAGING_MODE_HSV, rgb2hsv},
+
+    {IMAGING_MODE_RGBA, IMAGING_MODE_1, rgb2bit},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_L, rgb2l},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_LA, rgba2la},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_I, rgb2i},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_F, rgb2f},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_RGB, rgba2rgb},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_RGBa, rgbA2rgba},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_RGBX, rgb2rgba},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_CMYK, rgb2cmyk},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_YCbCr, ImagingConvertRGB2YCbCr},
+    {IMAGING_MODE_RGBA, IMAGING_MODE_HSV, rgb2hsv},
+
+    {IMAGING_MODE_RGBa, IMAGING_MODE_RGBA, rgba2rgbA},
+    {IMAGING_MODE_RGBa, IMAGING_MODE_RGB, rgba2rgb_},
+
+    {IMAGING_MODE_RGBX, IMAGING_MODE_1, rgb2bit},
+    {IMAGING_MODE_RGBX, IMAGING_MODE_L, rgb2l},
+    {IMAGING_MODE_RGBX, IMAGING_MODE_LA, rgb2la},
+    {IMAGING_MODE_RGBX, IMAGING_MODE_I, rgb2i},
+    {IMAGING_MODE_RGBX, IMAGING_MODE_F, rgb2f},
+    {IMAGING_MODE_RGBX, IMAGING_MODE_RGB, rgba2rgb},
+    {IMAGING_MODE_RGBX, IMAGING_MODE_CMYK, rgb2cmyk},
+    {IMAGING_MODE_RGBX, IMAGING_MODE_YCbCr, ImagingConvertRGB2YCbCr},
+    {IMAGING_MODE_RGBX, IMAGING_MODE_HSV, rgb2hsv},
+
+    {IMAGING_MODE_CMYK, IMAGING_MODE_RGB, cmyk2rgb},
+    {IMAGING_MODE_CMYK, IMAGING_MODE_RGBA, cmyk2rgb},
+    {IMAGING_MODE_CMYK, IMAGING_MODE_RGBX, cmyk2rgb},
+    {IMAGING_MODE_CMYK, IMAGING_MODE_HSV, cmyk2hsv},
+
+    {IMAGING_MODE_YCbCr, IMAGING_MODE_L, ycbcr2l},
+    {IMAGING_MODE_YCbCr, IMAGING_MODE_LA, ycbcr2la},
+    {IMAGING_MODE_YCbCr, IMAGING_MODE_RGB, ImagingConvertYCbCr2RGB},
+
+    {IMAGING_MODE_HSV, IMAGING_MODE_RGB, hsv2rgb},
+
+    {IMAGING_MODE_I, IMAGING_MODE_I_16, I_I16L},
+    {IMAGING_MODE_I_16, IMAGING_MODE_I, I16L_I},
+    {IMAGING_MODE_I_16, IMAGING_MODE_RGB, I16_RGB},
+    {IMAGING_MODE_L, IMAGING_MODE_I_16, L_I16L},
+    {IMAGING_MODE_I_16, IMAGING_MODE_L, I16L_L},
+
+    {IMAGING_MODE_I, IMAGING_MODE_I_16L, I_I16L},
+    {IMAGING_MODE_I_16L, IMAGING_MODE_I, I16L_I},
+    {IMAGING_MODE_I, IMAGING_MODE_I_16B, I_I16B},
+    {IMAGING_MODE_I_16B, IMAGING_MODE_I, I16B_I},
+
+    {IMAGING_MODE_L, IMAGING_MODE_I_16L, L_I16L},
+    {IMAGING_MODE_I_16L, IMAGING_MODE_L, I16L_L},
+    {IMAGING_MODE_L, IMAGING_MODE_I_16B, L_I16B},
+    {IMAGING_MODE_I_16B, IMAGING_MODE_L, I16B_L},
+#ifdef WORDS_BIGENDIAN
+    {IMAGING_MODE_L, IMAGING_MODE_I_16N, L_I16B},
+    {IMAGING_MODE_I_16N, IMAGING_MODE_L, I16B_L},
+#else
+    {IMAGING_MODE_L, IMAGING_MODE_I_16N, L_I16L},
+    {IMAGING_MODE_I_16N, IMAGING_MODE_L, I16L_L},
+#endif
+
+    {IMAGING_MODE_I_16, IMAGING_MODE_F, I16L_F},
+    {IMAGING_MODE_I_16L, IMAGING_MODE_F, I16L_F},
+    {IMAGING_MODE_I_16B, IMAGING_MODE_F, I16B_F}
+};
+
 static Imaging
-convert(
-    Imaging imOut, Imaging imIn, const char *mode, ImagingPalette palette, int dither
-) {
+convert(Imaging imOut, Imaging imIn, ModeID mode, ImagingPalette palette, int dither) {
     ImagingSectionCookie cookie;
     ImagingShuffler convert;
-    int y;
 
     if (!imIn) {
         return (Imaging)ImagingError_ModeError();
     }
 
-    if (!mode) {
+    if (mode == IMAGING_MODE_UNKNOWN) {
         /* Map palette image to full depth */
         if (!imIn->palette) {
             return (Imaging)ImagingError_ModeError();
@@ -1605,33 +1605,31 @@ convert(
         mode = imIn->palette->mode;
     } else {
         /* Same mode? */
-        if (!strcmp(imIn->mode, mode)) {
+        if (imIn->mode == mode) {
             return ImagingCopy2(imOut, imIn);
         }
     }
 
     /* test for special conversions */
 
-    if (strcmp(imIn->mode, "P") == 0 || strcmp(imIn->mode, "PA") == 0) {
+    if (imIn->mode == IMAGING_MODE_P || imIn->mode == IMAGING_MODE_PA) {
         return frompalette(imOut, imIn, mode);
     }
 
-    if (strcmp(mode, "P") == 0 || strcmp(mode, "PA") == 0) {
+    if (mode == IMAGING_MODE_P || mode == IMAGING_MODE_PA) {
         return topalette(imOut, imIn, mode, palette, dither);
     }
 
-    if (dither && strcmp(mode, "1") == 0) {
+    if (dither && mode == IMAGING_MODE_1) {
         return tobilevel(imOut, imIn);
     }
 
     /* standard conversion machinery */
 
     convert = NULL;
-
-    for (y = 0; converters[y].from; y++) {
-        if (!strcmp(imIn->mode, converters[y].from) &&
-            !strcmp(mode, converters[y].to)) {
-            convert = converters[y].convert;
+    for (size_t i = 0; i < sizeof(converters) / sizeof(*converters); i++) {
+        if (imIn->mode == converters[i].from && mode == converters[i].to) {
+            convert = converters[i].convert;
             break;
         }
     }
@@ -1642,7 +1640,11 @@ convert(
 #else
         static char buf[100];
         snprintf(
-            buf, 100, "conversion from %.10s to %.10s not supported", imIn->mode, mode
+            buf,
+            100,
+            "conversion from %.10s to %.10s not supported",
+            getModeData(imIn->mode)->name,
+            getModeData(mode)->name
         );
         return (Imaging)ImagingError_ValueError(buf);
 #endif
@@ -1654,7 +1656,7 @@ convert(
     }
 
     ImagingSectionEnter(&cookie);
-    for (y = 0; y < imIn->ysize; y++) {
+    for (int y = 0; y < imIn->ysize; y++) {
         (*convert)((UINT8 *)imOut->image[y], (UINT8 *)imIn->image[y], imIn->xsize);
     }
     ImagingSectionLeave(&cookie);
@@ -1663,7 +1665,7 @@ convert(
 }
 
 Imaging
-ImagingConvert(Imaging imIn, const char *mode, ImagingPalette palette, int dither) {
+ImagingConvert(Imaging imIn, const ModeID mode, ImagingPalette palette, int dither) {
     return convert(NULL, imIn, mode, palette, dither);
 }
 
@@ -1673,7 +1675,7 @@ ImagingConvert2(Imaging imOut, Imaging imIn) {
 }
 
 Imaging
-ImagingConvertTransparent(Imaging imIn, const char *mode, int r, int g, int b) {
+ImagingConvertTransparent(Imaging imIn, const ModeID mode, int r, int g, int b) {
     ImagingSectionCookie cookie;
     ImagingShuffler convert;
     Imaging imOut = NULL;
@@ -1687,27 +1689,27 @@ ImagingConvertTransparent(Imaging imIn, const char *mode, int r, int g, int b) {
         return (Imaging)ImagingError_ModeError();
     }
 
-    if (strcmp(imIn->mode, "RGB") == 0 &&
-        (strcmp(mode, "RGBA") == 0 || strcmp(mode, "RGBa") == 0)) {
+    if (imIn->mode == IMAGING_MODE_RGB &&
+        (mode == IMAGING_MODE_RGBA || mode == IMAGING_MODE_RGBa)) {
         convert = rgb2rgba;
-        if (strcmp(mode, "RGBa") == 0) {
+        if (mode == IMAGING_MODE_RGBa) {
             premultiplied = 1;
         }
-    } else if (strcmp(imIn->mode, "RGB") == 0 &&
-               (strcmp(mode, "LA") == 0 || strcmp(mode, "La") == 0)) {
+    } else if (imIn->mode == IMAGING_MODE_RGB &&
+               (mode == IMAGING_MODE_LA || mode == IMAGING_MODE_La)) {
         convert = rgb2la;
         source_transparency = 1;
-        if (strcmp(mode, "La") == 0) {
+        if (mode == IMAGING_MODE_La) {
             premultiplied = 1;
         }
-    } else if ((strcmp(imIn->mode, "1") == 0 || strcmp(imIn->mode, "I") == 0 ||
-                strcmp(imIn->mode, "I;16") == 0 || strcmp(imIn->mode, "L") == 0) &&
-               (strcmp(mode, "RGBA") == 0 || strcmp(mode, "LA") == 0)) {
-        if (strcmp(imIn->mode, "1") == 0) {
+    } else if ((imIn->mode == IMAGING_MODE_1 || imIn->mode == IMAGING_MODE_I ||
+                imIn->mode == IMAGING_MODE_I_16 || imIn->mode == IMAGING_MODE_L) &&
+               (mode == IMAGING_MODE_RGBA || mode == IMAGING_MODE_LA)) {
+        if (imIn->mode == IMAGING_MODE_1) {
             convert = bit2rgb;
-        } else if (strcmp(imIn->mode, "I") == 0) {
+        } else if (imIn->mode == IMAGING_MODE_I) {
             convert = i2rgb;
-        } else if (strcmp(imIn->mode, "I;16") == 0) {
+        } else if (imIn->mode == IMAGING_MODE_I_16) {
             convert = I16_RGB;
         } else {
             convert = l2rgb;
@@ -1719,8 +1721,8 @@ ImagingConvertTransparent(Imaging imIn, const char *mode, int r, int g, int b) {
             buf,
             100,
             "conversion from %.10s to %.10s not supported in convert_transparent",
-            imIn->mode,
-            mode
+            getModeData(imIn->mode)->name,
+            getModeData(mode)->name
         );
         return (Imaging)ImagingError_ValueError(buf);
     }
@@ -1743,15 +1745,15 @@ ImagingConvertTransparent(Imaging imIn, const char *mode, int r, int g, int b) {
 }
 
 Imaging
-ImagingConvertInPlace(Imaging imIn, const char *mode) {
+ImagingConvertInPlace(Imaging imIn, const ModeID mode) {
     ImagingSectionCookie cookie;
     ImagingShuffler convert;
     int y;
 
     /* limited support for inplace conversion */
-    if (strcmp(imIn->mode, "L") == 0 && strcmp(mode, "1") == 0) {
+    if (imIn->mode == IMAGING_MODE_L && mode == IMAGING_MODE_1) {
         convert = l2bit;
-    } else if (strcmp(imIn->mode, "1") == 0 && strcmp(mode, "L") == 0) {
+    } else if (imIn->mode == IMAGING_MODE_1 && mode == IMAGING_MODE_L) {
         convert = bit2l;
     } else {
         return ImagingError_ModeError();

src/libImaging/Dib.c

@@ -25,20 +25,17 @@
 
 #include "ImDib.h"
 
-char *
+ModeID
 ImagingGetModeDIB(int size_out[2]) {
     /* Get device characteristics */
 
-    HDC dc;
-    char *mode;
+    const HDC dc = CreateCompatibleDC(NULL);
 
-    dc = CreateCompatibleDC(NULL);
-
-    mode = "P";
+    ModeID mode = IMAGING_MODE_P;
     if (!(GetDeviceCaps(dc, RASTERCAPS) & RC_PALETTE)) {
-        mode = "RGB";
+        mode = IMAGING_MODE_RGB;
         if (GetDeviceCaps(dc, BITSPIXEL) == 1) {
-            mode = "1";
+            mode = IMAGING_MODE_1;
         }
     }
 
@@ -53,7 +50,7 @@ ImagingGetModeDIB(int size_out[2]) {
 }
 
 ImagingDIB
-ImagingNewDIB(const char *mode, int xsize, int ysize) {
+ImagingNewDIB(const ModeID mode, int xsize, int ysize) {
     /* Create a Windows bitmap */
 
     ImagingDIB dib;
@@ -61,10 +58,12 @@ ImagingNewDIB(const char *mode, int xsize, int ysize) {
     int i;
 
     /* Check mode */
-    if (strcmp(mode, "1") != 0 && strcmp(mode, "L") != 0 && strcmp(mode, "RGB") != 0) {
+    if (mode != IMAGING_MODE_1 && mode != IMAGING_MODE_L && mode != IMAGING_MODE_RGB) {
         return (ImagingDIB)ImagingError_ModeError();
     }
 
+    const int pixelsize = mode == IMAGING_MODE_RGB ? 3 : 1;
+
     /* Create DIB context and info header */
     /* malloc check ok, small constant allocation */
     dib = (ImagingDIB)malloc(sizeof(*dib));
@@ -83,7 +82,7 @@ ImagingNewDIB(const char *mode, int xsize, int ysize) {
     dib->info->bmiHeader.biWidth = xsize;
     dib->info->bmiHeader.biHeight = ysize;
     dib->info->bmiHeader.biPlanes = 1;
-    dib->info->bmiHeader.biBitCount = strlen(mode) * 8;
+    dib->info->bmiHeader.biBitCount = pixelsize * 8;
     dib->info->bmiHeader.biCompression = BI_RGB;
 
     /* Create DIB */
@@ -103,12 +102,12 @@ ImagingNewDIB(const char *mode, int xsize, int ysize) {
         return (ImagingDIB)ImagingError_MemoryError();
     }
 
-    strcpy(dib->mode, mode);
+    dib->mode = mode;
     dib->xsize = xsize;
     dib->ysize = ysize;
 
-    dib->pixelsize = strlen(mode);
-    dib->linesize = (xsize * dib->pixelsize + 3) & -4;
+    dib->pixelsize = pixelsize;
+    dib->linesize = (xsize * pixelsize + 3) & -4;
 
     if (dib->pixelsize == 1) {
         dib->pack = dib->unpack = (ImagingShuffler)memcpy;
@@ -132,7 +131,7 @@ ImagingNewDIB(const char *mode, int xsize, int ysize) {
     }
 
     /* Create an associated palette (for 8-bit displays only) */
-    if (strcmp(ImagingGetModeDIB(NULL), "P") == 0) {
+    if (ImagingGetModeDIB(NULL) == IMAGING_MODE_P) {
         char palbuf[sizeof(LOGPALETTE) + 256 * sizeof(PALETTEENTRY)];
         LPLOGPALETTE pal = (LPLOGPALETTE)palbuf;
         int i, r, g, b;
@@ -142,7 +141,7 @@ ImagingNewDIB(const char *mode, int xsize, int ysize) {
         pal->palNumEntries = 256;
         GetSystemPaletteEntries(dib->dc, 0, 256, pal->palPalEntry);
 
-        if (strcmp(mode, "L") == 0) {
+        if (mode == IMAGING_MODE_L) {
             /* Grayscale DIB.  Fill all 236 slots with a grayscale ramp
              * (this is usually overkill on Windows since VGA only offers
              * 6 bits grayscale resolution).  Ignore the slots already
@@ -156,8 +155,7 @@ ImagingNewDIB(const char *mode, int xsize, int ysize) {
             }
 
             dib->palette = CreatePalette(pal);
-
-        } else if (strcmp(mode, "RGB") == 0) {
+        } else if (mode == IMAGING_MODE_RGB) {
 #ifdef CUBE216
 
             /* Colour DIB.  Create a 6x6x6 colour cube (216 entries) and

src/libImaging/Draw.c

@@ -68,7 +68,7 @@ typedef void (*hline_handler)(Imaging, int, int, int, int, Imaging);
 static inline void
 point8(Imaging im, int x, int y, int ink) {
     if (x >= 0 && x < im->xsize && y >= 0 && y < im->ysize) {
-        if (strncmp(im->mode, "I;16", 4) == 0) {
+        if (isModeI16(im->mode)) {
 #ifdef WORDS_BIGENDIAN
             im->image8[y][x * 2] = (UINT8)(ink >> 8);
             im->image8[y][x * 2 + 1] = (UINT8)ink;
@@ -117,13 +117,13 @@ hline8(Imaging im, int x0, int y0, int x1, int ink, Imaging mask) {
         }
         if (x0 <= x1) {
             int bigendian = -1;
-            if (strncmp(im->mode, "I;16", 4) == 0) {
+            if (isModeI16(im->mode)) {
                 bigendian =
                     (
 #ifdef WORDS_BIGENDIAN
-                        strcmp(im->mode, "I;16") == 0 || strcmp(im->mode, "I;16L") == 0
+                        im->mode == IMAGING_MODE_I_16 || im->mode == IMAGING_MODE_I_16L
 #else
-                        strcmp(im->mode, "I;16B") == 0
+                        im->mode == IMAGING_MODE_I_16B
 #endif
                     )
                         ? 1
@@ -675,7 +675,7 @@ DRAW draw32rgba = {point32rgba, hline32rgba, line32rgba};
 #define DRAWINIT()                           \
     if (im->image8) {                        \
         draw = &draw8;                       \
-        if (strncmp(im->mode, "I;16", 4) == 0) { \
+        if (isModeI16(im->mode)) {           \
             ink = INK16(ink_);               \
         } else {                             \
             ink = INK8(ink_);                \

src/libImaging/Effects.c

@@ -36,7 +36,7 @@ ImagingEffectMandelbrot(int xsize, int ysize, double extent[4], int quality) {
         return (Imaging)ImagingError_ValueError(NULL);
     }
 
-    im = ImagingNewDirty("L", xsize, ysize);
+    im = ImagingNewDirty(IMAGING_MODE_L, xsize, ysize);
     if (!im) {
         return NULL;
     }
@@ -80,7 +80,7 @@ ImagingEffectNoise(int xsize, int ysize, float sigma) {
     int nextok;
     double this, next;
 
-    imOut = ImagingNewDirty("L", xsize, ysize);
+    imOut = ImagingNewDirty(IMAGING_MODE_L, xsize, ysize);
     if (!imOut) {
         return NULL;
     }

src/libImaging/File.c

@@ -23,14 +23,13 @@ int
 ImagingSaveRaw(Imaging im, FILE *fp) {
     int x, y, i;
 
-    if (strcmp(im->mode, "1") == 0 || strcmp(im->mode, "L") == 0) {
+    if (im->mode == IMAGING_MODE_1 || im->mode == IMAGING_MODE_L) {
         /* @PIL227: FIXME: for mode "1", map != 0 to 255 */
 
         /* PGM "L" */
         for (y = 0; y < im->ysize; y++) {
             fwrite(im->image[y], 1, im->xsize, fp);
         }
-
     } else {
         /* PPM "RGB" or other internal format */
         for (y = 0; y < im->ysize; y++) {
@@ -58,10 +57,10 @@ ImagingSavePPM(Imaging im, const char *outfile) {
         return 0;
     }
 
-    if (strcmp(im->mode, "1") == 0 || strcmp(im->mode, "L") == 0) {
+    if (im->mode == IMAGING_MODE_1 || im->mode == IMAGING_MODE_L) {
         /* Write "PGM" */
         fprintf(fp, "P5\n%d %d\n255\n", im->xsize, im->ysize);
-    } else if (strcmp(im->mode, "RGB") == 0) {
+    } else if (im->mode == IMAGING_MODE_RGB) {
         /* Write "PPM" */
         fprintf(fp, "P6\n%d %d\n255\n", im->xsize, im->ysize);
     } else {

src/libImaging/Fill.c

@@ -68,11 +68,12 @@ ImagingFill(Imaging im, const void *colour) {
 }
 
 Imaging
-ImagingFillLinearGradient(const char *mode) {
+ImagingFillLinearGradient(const ModeID mode) {
     Imaging im;
     int y;
 
-    if (strlen(mode) != 1) {
+    if (mode != IMAGING_MODE_1 && mode != IMAGING_MODE_F && mode != IMAGING_MODE_I &&
+        mode != IMAGING_MODE_L && mode != IMAGING_MODE_P) {
         return (Imaging)ImagingError_ModeError();
     }
 
@@ -102,12 +103,13 @@ ImagingFillLinearGradient(const char *mode) {
 }
 
 Imaging
-ImagingFillRadialGradient(const char *mode) {
+ImagingFillRadialGradient(const ModeID mode) {
     Imaging im;
     int x, y;
     int d;
 
-    if (strlen(mode) != 1) {
+    if (mode != IMAGING_MODE_1 && mode != IMAGING_MODE_F && mode != IMAGING_MODE_I &&
+        mode != IMAGING_MODE_L && mode != IMAGING_MODE_P) {
         return (Imaging)ImagingError_ModeError();
     }