two version of R2R are here HEAD master

1 files changed, 1544 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/PIL/PngImagePlugin.py b/.venv/lib/python3.12/site-packages/PIL/PngImagePlugin.py
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@@ -0,0 +1,1544 @@
+#
+# The Python Imaging Library.
+# $Id$
+#
+# PNG support code
+#
+# See "PNG (Portable Network Graphics) Specification, version 1.0;
+# W3C Recommendation", 1996-10-01, Thomas Boutell (ed.).
+#
+# history:
+# 1996-05-06 fl   Created (couldn't resist it)
+# 1996-12-14 fl   Upgraded, added read and verify support (0.2)
+# 1996-12-15 fl   Separate PNG stream parser
+# 1996-12-29 fl   Added write support, added getchunks
+# 1996-12-30 fl   Eliminated circular references in decoder (0.3)
+# 1998-07-12 fl   Read/write 16-bit images as mode I (0.4)
+# 2001-02-08 fl   Added transparency support (from Zircon) (0.5)
+# 2001-04-16 fl   Don't close data source in "open" method (0.6)
+# 2004-02-24 fl   Don't even pretend to support interlaced files (0.7)
+# 2004-08-31 fl   Do basic sanity check on chunk identifiers (0.8)
+# 2004-09-20 fl   Added PngInfo chunk container
+# 2004-12-18 fl   Added DPI read support (based on code by Niki Spahiev)
+# 2008-08-13 fl   Added tRNS support for RGB images
+# 2009-03-06 fl   Support for preserving ICC profiles (by Florian Hoech)
+# 2009-03-08 fl   Added zTXT support (from Lowell Alleman)
+# 2009-03-29 fl   Read interlaced PNG files (from Conrado Porto Lopes Gouvua)
+#
+# Copyright (c) 1997-2009 by Secret Labs AB
+# Copyright (c) 1996 by Fredrik Lundh
+#
+# See the README file for information on usage and redistribution.
+#
+from __future__ import annotations
+
+import itertools
+import logging
+import re
+import struct
+import warnings
+import zlib
+from collections.abc import Callable
+from enum import IntEnum
+from typing import IO, TYPE_CHECKING, Any, NamedTuple, NoReturn, cast
+
+from . import Image, ImageChops, ImageFile, ImagePalette, ImageSequence
+from ._binary import i16be as i16
+from ._binary import i32be as i32
+from ._binary import o8
+from ._binary import o16be as o16
+from ._binary import o32be as o32
+
+if TYPE_CHECKING:
+    from . import _imaging
+
+logger = logging.getLogger(__name__)
+
+is_cid = re.compile(rb"\w\w\w\w").match
+
+
+_MAGIC = b"\211PNG\r\n\032\n"
+
+
+_MODES = {
+    # supported bits/color combinations, and corresponding modes/rawmodes
+    # Grayscale
+    (1, 0): ("1", "1"),
+    (2, 0): ("L", "L;2"),
+    (4, 0): ("L", "L;4"),
+    (8, 0): ("L", "L"),
+    (16, 0): ("I;16", "I;16B"),
+    # Truecolour
+    (8, 2): ("RGB", "RGB"),
+    (16, 2): ("RGB", "RGB;16B"),
+    # Indexed-colour
+    (1, 3): ("P", "P;1"),
+    (2, 3): ("P", "P;2"),
+    (4, 3): ("P", "P;4"),
+    (8, 3): ("P", "P"),
+    # Grayscale with alpha
+    (8, 4): ("LA", "LA"),
+    (16, 4): ("RGBA", "LA;16B"),  # LA;16B->LA not yet available
+    # Truecolour with alpha
+    (8, 6): ("RGBA", "RGBA"),
+    (16, 6): ("RGBA", "RGBA;16B"),
+}
+
+
+_simple_palette = re.compile(b"^\xff*\x00\xff*$")
+
+MAX_TEXT_CHUNK = ImageFile.SAFEBLOCK
+"""
+Maximum decompressed size for a iTXt or zTXt chunk.
+Eliminates decompression bombs where compressed chunks can expand 1000x.
+See :ref:`Text in PNG File Format<png-text>`.
+"""
+MAX_TEXT_MEMORY = 64 * MAX_TEXT_CHUNK
+"""
+Set the maximum total text chunk size.
+See :ref:`Text in PNG File Format<png-text>`.
+"""
+
+
+# APNG frame disposal modes
+class Disposal(IntEnum):
+    OP_NONE = 0
+    """
+    No disposal is done on this frame before rendering the next frame.
+    See :ref:`Saving APNG sequences<apng-saving>`.
+    """
+    OP_BACKGROUND = 1
+    """
+    This frame’s modified region is cleared to fully transparent black before rendering
+    the next frame.
+    See :ref:`Saving APNG sequences<apng-saving>`.
+    """
+    OP_PREVIOUS = 2
+    """
+    This frame’s modified region is reverted to the previous frame’s contents before
+    rendering the next frame.
+    See :ref:`Saving APNG sequences<apng-saving>`.
+    """
+
+
+# APNG frame blend modes
+class Blend(IntEnum):
+    OP_SOURCE = 0
+    """
+    All color components of this frame, including alpha, overwrite the previous output
+    image contents.
+    See :ref:`Saving APNG sequences<apng-saving>`.
+    """
+    OP_OVER = 1
+    """
+    This frame should be alpha composited with the previous output image contents.
+    See :ref:`Saving APNG sequences<apng-saving>`.
+    """
+
+
+def _safe_zlib_decompress(s: bytes) -> bytes:
+    dobj = zlib.decompressobj()
+    plaintext = dobj.decompress(s, MAX_TEXT_CHUNK)
+    if dobj.unconsumed_tail:
+        msg = "Decompressed data too large for PngImagePlugin.MAX_TEXT_CHUNK"
+        raise ValueError(msg)
+    return plaintext
+
+
+def _crc32(data: bytes, seed: int = 0) -> int:
+    return zlib.crc32(data, seed) & 0xFFFFFFFF
+
+
+# --------------------------------------------------------------------
+# Support classes.  Suitable for PNG and related formats like MNG etc.
+
+
+class ChunkStream:
+    def __init__(self, fp: IO[bytes]) -> None:
+        self.fp: IO[bytes] | None = fp
+        self.queue: list[tuple[bytes, int, int]] | None = []
+
+    def read(self) -> tuple[bytes, int, int]:
+        """Fetch a new chunk. Returns header information."""
+        cid = None
+
+        assert self.fp is not None
+        if self.queue:
+            cid, pos, length = self.queue.pop()
+            self.fp.seek(pos)
+        else:
+            s = self.fp.read(8)
+            cid = s[4:]
+            pos = self.fp.tell()
+            length = i32(s)
+
+        if not is_cid(cid):
+            if not ImageFile.LOAD_TRUNCATED_IMAGES:
+                msg = f"broken PNG file (chunk {repr(cid)})"
+                raise SyntaxError(msg)
+
+        return cid, pos, length
+
+    def __enter__(self) -> ChunkStream:
+        return self
+
+    def __exit__(self, *args: object) -> None:
+        self.close()
+
+    def close(self) -> None:
+        self.queue = self.fp = None
+
+    def push(self, cid: bytes, pos: int, length: int) -> None:
+        assert self.queue is not None
+        self.queue.append((cid, pos, length))
+
+    def call(self, cid: bytes, pos: int, length: int) -> bytes:
+        """Call the appropriate chunk handler"""
+
+        logger.debug("STREAM %r %s %s", cid, pos, length)
+        return getattr(self, f"chunk_{cid.decode('ascii')}")(pos, length)
+
+    def crc(self, cid: bytes, data: bytes) -> None:
+        """Read and verify checksum"""
+
+        # Skip CRC checks for ancillary chunks if allowed to load truncated
+        # images
+        # 5th byte of first char is 1 [specs, section 5.4]
+        if ImageFile.LOAD_TRUNCATED_IMAGES and (cid[0] >> 5 & 1):
+            self.crc_skip(cid, data)
+            return
+
+        assert self.fp is not None
+        try:
+            crc1 = _crc32(data, _crc32(cid))
+            crc2 = i32(self.fp.read(4))
+            if crc1 != crc2:
+                msg = f"broken PNG file (bad header checksum in {repr(cid)})"
+                raise SyntaxError(msg)
+        except struct.error as e:
+            msg = f"broken PNG file (incomplete checksum in {repr(cid)})"
+            raise SyntaxError(msg) from e
+
+    def crc_skip(self, cid: bytes, data: bytes) -> None:
+        """Read checksum"""
+
+        assert self.fp is not None
+        self.fp.read(4)
+
+    def verify(self, endchunk: bytes = b"IEND") -> list[bytes]:
+        # Simple approach; just calculate checksum for all remaining
+        # blocks.  Must be called directly after open.
+
+        cids = []
+
+        assert self.fp is not None
+        while True:
+            try:
+                cid, pos, length = self.read()
+            except struct.error as e:
+                msg = "truncated PNG file"
+                raise OSError(msg) from e
+
+            if cid == endchunk:
+                break
+            self.crc(cid, ImageFile._safe_read(self.fp, length))
+            cids.append(cid)
+
+        return cids
+
+
+class iTXt(str):
+    """
+    Subclass of string to allow iTXt chunks to look like strings while
+    keeping their extra information
+
+    """
+
+    lang: str | bytes | None
+    tkey: str | bytes | None
+
+    @staticmethod
+    def __new__(
+        cls, text: str, lang: str | None = None, tkey: str | None = None
+    ) -> iTXt:
+        """
+        :param cls: the class to use when creating the instance
+        :param text: value for this key
+        :param lang: language code
+        :param tkey: UTF-8 version of the key name
+        """
+
+        self = str.__new__(cls, text)
+        self.lang = lang
+        self.tkey = tkey
+        return self
+
+
+class PngInfo:
+    """
+    PNG chunk container (for use with save(pnginfo=))
+
+    """
+
+    def __init__(self) -> None:
+        self.chunks: list[tuple[bytes, bytes, bool]] = []
+
+    def add(self, cid: bytes, data: bytes, after_idat: bool = False) -> None:
+        """Appends an arbitrary chunk. Use with caution.
+
+        :param cid: a byte string, 4 bytes long.
+        :param data: a byte string of the encoded data
+        :param after_idat: for use with private chunks. Whether the chunk
+                           should be written after IDAT
+
+        """
+
+        self.chunks.append((cid, data, after_idat))
+
+    def add_itxt(
+        self,
+        key: str | bytes,
+        value: str | bytes,
+        lang: str | bytes = "",
+        tkey: str | bytes = "",
+        zip: bool = False,
+    ) -> None:
+        """Appends an iTXt chunk.
+
+        :param key: latin-1 encodable text key name
+        :param value: value for this key
+        :param lang: language code
+        :param tkey: UTF-8 version of the key name
+        :param zip: compression flag
+
+        """
+
+        if not isinstance(key, bytes):
+            key = key.encode("latin-1", "strict")
+        if not isinstance(value, bytes):
+            value = value.encode("utf-8", "strict")
+        if not isinstance(lang, bytes):
+            lang = lang.encode("utf-8", "strict")
+        if not isinstance(tkey, bytes):
+            tkey = tkey.encode("utf-8", "strict")
+
+        if zip:
+            self.add(
+                b"iTXt",
+                key + b"\0\x01\0" + lang + b"\0" + tkey + b"\0" + zlib.compress(value),
+            )
+        else:
+            self.add(b"iTXt", key + b"\0\0\0" + lang + b"\0" + tkey + b"\0" + value)
+
+    def add_text(
+        self, key: str | bytes, value: str | bytes | iTXt, zip: bool = False
+    ) -> None:
+        """Appends a text chunk.
+
+        :param key: latin-1 encodable text key name
+        :param value: value for this key, text or an
+           :py:class:`PIL.PngImagePlugin.iTXt` instance
+        :param zip: compression flag
+
+        """
+        if isinstance(value, iTXt):
+            return self.add_itxt(
+                key,
+                value,
+                value.lang if value.lang is not None else b"",
+                value.tkey if value.tkey is not None else b"",
+                zip=zip,
+            )
+
+        # The tEXt chunk stores latin-1 text
+        if not isinstance(value, bytes):
+            try:
+                value = value.encode("latin-1", "strict")
+            except UnicodeError:
+                return self.add_itxt(key, value, zip=zip)
+
+        if not isinstance(key, bytes):
+            key = key.encode("latin-1", "strict")
+
+        if zip:
+            self.add(b"zTXt", key + b"\0\0" + zlib.compress(value))
+        else:
+            self.add(b"tEXt", key + b"\0" + value)
+
+
+# --------------------------------------------------------------------
+# PNG image stream (IHDR/IEND)
+
+
+class _RewindState(NamedTuple):
+    info: dict[str | tuple[int, int], Any]
+    tile: list[ImageFile._Tile]
+    seq_num: int | None
+
+
+class PngStream(ChunkStream):
+    def __init__(self, fp: IO[bytes]) -> None:
+        super().__init__(fp)
+
+        # local copies of Image attributes
+        self.im_info: dict[str | tuple[int, int], Any] = {}
+        self.im_text: dict[str, str | iTXt] = {}
+        self.im_size = (0, 0)
+        self.im_mode = ""
+        self.im_tile: list[ImageFile._Tile] = []
+        self.im_palette: tuple[str, bytes] | None = None
+        self.im_custom_mimetype: str | None = None
+        self.im_n_frames: int | None = None
+        self._seq_num: int | None = None
+        self.rewind_state = _RewindState({}, [], None)
+
+        self.text_memory = 0
+
+    def check_text_memory(self, chunklen: int) -> None:
+        self.text_memory += chunklen
+        if self.text_memory > MAX_TEXT_MEMORY:
+            msg = (
+                "Too much memory used in text chunks: "
+                f"{self.text_memory}>MAX_TEXT_MEMORY"
+            )
+            raise ValueError(msg)
+
+    def save_rewind(self) -> None:
+        self.rewind_state = _RewindState(
+            self.im_info.copy(),
+            self.im_tile,
+            self._seq_num,
+        )
+
+    def rewind(self) -> None:
+        self.im_info = self.rewind_state.info.copy()
+        self.im_tile = self.rewind_state.tile
+        self._seq_num = self.rewind_state.seq_num
+
+    def chunk_iCCP(self, pos: int, length: int) -> bytes:
+        # ICC profile
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        # according to PNG spec, the iCCP chunk contains:
+        # Profile name  1-79 bytes (character string)
+        # Null separator        1 byte (null character)
+        # Compression method    1 byte (0)
+        # Compressed profile    n bytes (zlib with deflate compression)
+        i = s.find(b"\0")
+        logger.debug("iCCP profile name %r", s[:i])
+        comp_method = s[i + 1]
+        logger.debug("Compression method %s", comp_method)
+        if comp_method != 0:
+            msg = f"Unknown compression method {comp_method} in iCCP chunk"
+            raise SyntaxError(msg)
+        try:
+            icc_profile = _safe_zlib_decompress(s[i + 2 :])
+        except ValueError:
+            if ImageFile.LOAD_TRUNCATED_IMAGES:
+                icc_profile = None
+            else:
+                raise
+        except zlib.error:
+            icc_profile = None  # FIXME
+        self.im_info["icc_profile"] = icc_profile
+        return s
+
+    def chunk_IHDR(self, pos: int, length: int) -> bytes:
+        # image header
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        if length < 13:
+            if ImageFile.LOAD_TRUNCATED_IMAGES:
+                return s
+            msg = "Truncated IHDR chunk"
+            raise ValueError(msg)
+        self.im_size = i32(s, 0), i32(s, 4)
+        try:
+            self.im_mode, self.im_rawmode = _MODES[(s[8], s[9])]
+        except Exception:
+            pass
+        if s[12]:
+            self.im_info["interlace"] = 1
+        if s[11]:
+            msg = "unknown filter category"
+            raise SyntaxError(msg)
+        return s
+
+    def chunk_IDAT(self, pos: int, length: int) -> NoReturn:
+        # image data
+        if "bbox" in self.im_info:
+            tile = [ImageFile._Tile("zip", self.im_info["bbox"], pos, self.im_rawmode)]
+        else:
+            if self.im_n_frames is not None:
+                self.im_info["default_image"] = True
+            tile = [ImageFile._Tile("zip", (0, 0) + self.im_size, pos, self.im_rawmode)]
+        self.im_tile = tile
+        self.im_idat = length
+        msg = "image data found"
+        raise EOFError(msg)
+
+    def chunk_IEND(self, pos: int, length: int) -> NoReturn:
+        msg = "end of PNG image"
+        raise EOFError(msg)
+
+    def chunk_PLTE(self, pos: int, length: int) -> bytes:
+        # palette
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        if self.im_mode == "P":
+            self.im_palette = "RGB", s
+        return s
+
+    def chunk_tRNS(self, pos: int, length: int) -> bytes:
+        # transparency
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        if self.im_mode == "P":
+            if _simple_palette.match(s):
+                # tRNS contains only one full-transparent entry,
+                # other entries are full opaque
+                i = s.find(b"\0")
+                if i >= 0:
+                    self.im_info["transparency"] = i
+            else:
+                # otherwise, we have a byte string with one alpha value
+                # for each palette entry
+                self.im_info["transparency"] = s
+        elif self.im_mode in ("1", "L", "I;16"):
+            self.im_info["transparency"] = i16(s)
+        elif self.im_mode == "RGB":
+            self.im_info["transparency"] = i16(s), i16(s, 2), i16(s, 4)
+        return s
+
+    def chunk_gAMA(self, pos: int, length: int) -> bytes:
+        # gamma setting
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        self.im_info["gamma"] = i32(s) / 100000.0
+        return s
+
+    def chunk_cHRM(self, pos: int, length: int) -> bytes:
+        # chromaticity, 8 unsigned ints, actual value is scaled by 100,000
+        # WP x,y, Red x,y, Green x,y Blue x,y
+
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        raw_vals = struct.unpack(f">{len(s) // 4}I", s)
+        self.im_info["chromaticity"] = tuple(elt / 100000.0 for elt in raw_vals)
+        return s
+
+    def chunk_sRGB(self, pos: int, length: int) -> bytes:
+        # srgb rendering intent, 1 byte
+        # 0 perceptual
+        # 1 relative colorimetric
+        # 2 saturation
+        # 3 absolute colorimetric
+
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        if length < 1:
+            if ImageFile.LOAD_TRUNCATED_IMAGES:
+                return s
+            msg = "Truncated sRGB chunk"
+            raise ValueError(msg)
+        self.im_info["srgb"] = s[0]
+        return s
+
+    def chunk_pHYs(self, pos: int, length: int) -> bytes:
+        # pixels per unit
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        if length < 9:
+            if ImageFile.LOAD_TRUNCATED_IMAGES:
+                return s
+            msg = "Truncated pHYs chunk"
+            raise ValueError(msg)
+        px, py = i32(s, 0), i32(s, 4)
+        unit = s[8]
+        if unit == 1:  # meter
+            dpi = px * 0.0254, py * 0.0254
+            self.im_info["dpi"] = dpi
+        elif unit == 0:
+            self.im_info["aspect"] = px, py
+        return s
+
+    def chunk_tEXt(self, pos: int, length: int) -> bytes:
+        # text
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        try:
+            k, v = s.split(b"\0", 1)
+        except ValueError:
+            # fallback for broken tEXt tags
+            k = s
+            v = b""
+        if k:
+            k_str = k.decode("latin-1", "strict")
+            v_str = v.decode("latin-1", "replace")
+
+            self.im_info[k_str] = v if k == b"exif" else v_str
+            self.im_text[k_str] = v_str
+            self.check_text_memory(len(v_str))
+
+        return s
+
+    def chunk_zTXt(self, pos: int, length: int) -> bytes:
+        # compressed text
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        try:
+            k, v = s.split(b"\0", 1)
+        except ValueError:
+            k = s
+            v = b""
+        if v:
+            comp_method = v[0]
+        else:
+            comp_method = 0
+        if comp_method != 0:
+            msg = f"Unknown compression method {comp_method} in zTXt chunk"
+            raise SyntaxError(msg)
+        try:
+            v = _safe_zlib_decompress(v[1:])
+        except ValueError:
+            if ImageFile.LOAD_TRUNCATED_IMAGES:
+                v = b""
+            else:
+                raise
+        except zlib.error:
+            v = b""
+
+        if k:
+            k_str = k.decode("latin-1", "strict")
+            v_str = v.decode("latin-1", "replace")
+
+            self.im_info[k_str] = self.im_text[k_str] = v_str
+            self.check_text_memory(len(v_str))
+
+        return s
+
+    def chunk_iTXt(self, pos: int, length: int) -> bytes:
+        # international text
+        assert self.fp is not None
+        r = s = ImageFile._safe_read(self.fp, length)
+        try:
+            k, r = r.split(b"\0", 1)
+        except ValueError:
+            return s
+        if len(r) < 2:
+            return s
+        cf, cm, r = r[0], r[1], r[2:]
+        try:
+            lang, tk, v = r.split(b"\0", 2)
+        except ValueError:
+            return s
+        if cf != 0:
+            if cm == 0:
+                try:
+                    v = _safe_zlib_decompress(v)
+                except ValueError:
+                    if ImageFile.LOAD_TRUNCATED_IMAGES:
+                        return s
+                    else:
+                        raise
+                except zlib.error:
+                    return s
+            else:
+                return s
+        if k == b"XML:com.adobe.xmp":
+            self.im_info["xmp"] = v
+        try:
+            k_str = k.decode("latin-1", "strict")
+            lang_str = lang.decode("utf-8", "strict")
+            tk_str = tk.decode("utf-8", "strict")
+            v_str = v.decode("utf-8", "strict")
+        except UnicodeError:
+            return s
+
+        self.im_info[k_str] = self.im_text[k_str] = iTXt(v_str, lang_str, tk_str)
+        self.check_text_memory(len(v_str))
+
+        return s
+
+    def chunk_eXIf(self, pos: int, length: int) -> bytes:
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        self.im_info["exif"] = b"Exif\x00\x00" + s
+        return s
+
+    # APNG chunks
+    def chunk_acTL(self, pos: int, length: int) -> bytes:
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        if length < 8:
+            if ImageFile.LOAD_TRUNCATED_IMAGES:
+                return s
+            msg = "APNG contains truncated acTL chunk"
+            raise ValueError(msg)
+        if self.im_n_frames is not None:
+            self.im_n_frames = None
+            warnings.warn("Invalid APNG, will use default PNG image if possible")
+            return s
+        n_frames = i32(s)
+        if n_frames == 0 or n_frames > 0x80000000:
+            warnings.warn("Invalid APNG, will use default PNG image if possible")
+            return s
+        self.im_n_frames = n_frames
+        self.im_info["loop"] = i32(s, 4)
+        self.im_custom_mimetype = "image/apng"
+        return s
+
+    def chunk_fcTL(self, pos: int, length: int) -> bytes:
+        assert self.fp is not None
+        s = ImageFile._safe_read(self.fp, length)
+        if length < 26:
+            if ImageFile.LOAD_TRUNCATED_IMAGES:
+                return s
+            msg = "APNG contains truncated fcTL chunk"
+            raise ValueError(msg)
+        seq = i32(s)
+        if (self._seq_num is None and seq != 0) or (
+            self._seq_num is not None and self._seq_num != seq - 1
+        ):
+            msg = "APNG contains frame sequence errors"
+            raise SyntaxError(msg)
+        self._seq_num = seq
+        width, height = i32(s, 4), i32(s, 8)
+        px, py = i32(s, 12), i32(s, 16)
+        im_w, im_h = self.im_size
+        if px + width > im_w or py + height > im_h:
+            msg = "APNG contains invalid frames"
+            raise SyntaxError(msg)
+        self.im_info["bbox"] = (px, py, px + width, py + height)
+        delay_num, delay_den = i16(s, 20), i16(s, 22)
+        if delay_den == 0:
+            delay_den = 100
+        self.im_info["duration"] = float(delay_num) / float(delay_den) * 1000
+        self.im_info["disposal"] = s[24]
+        self.im_info["blend"] = s[25]
+        return s
+
+    def chunk_fdAT(self, pos: int, length: int) -> bytes:
+        assert self.fp is not None
+        if length < 4:
+            if ImageFile.LOAD_TRUNCATED_IMAGES:
+                s = ImageFile._safe_read(self.fp, length)
+                return s
+            msg = "APNG contains truncated fDAT chunk"
+            raise ValueError(msg)
+        s = ImageFile._safe_read(self.fp, 4)
+        seq = i32(s)
+        if self._seq_num != seq - 1:
+            msg = "APNG contains frame sequence errors"
+            raise SyntaxError(msg)
+        self._seq_num = seq
+        return self.chunk_IDAT(pos + 4, length - 4)
+
+
+# --------------------------------------------------------------------
+# PNG reader
+
+
+def _accept(prefix: bytes) -> bool:
+    return prefix[:8] == _MAGIC
+
+
+##
+# Image plugin for PNG images.
+
+
+class PngImageFile(ImageFile.ImageFile):
+    format = "PNG"
+    format_description = "Portable network graphics"
+
+    def _open(self) -> None:
+        if not _accept(self.fp.read(8)):
+            msg = "not a PNG file"
+            raise SyntaxError(msg)
+        self._fp = self.fp
+        self.__frame = 0
+
+        #
+        # Parse headers up to the first IDAT or fDAT chunk
+
+        self.private_chunks: list[tuple[bytes, bytes] | tuple[bytes, bytes, bool]] = []
+        self.png: PngStream | None = PngStream(self.fp)
+
+        while True:
+            #
+            # get next chunk
+
+            cid, pos, length = self.png.read()
+
+            try:
+                s = self.png.call(cid, pos, length)
+            except EOFError:
+                break
+            except AttributeError:
+                logger.debug("%r %s %s (unknown)", cid, pos, length)
+                s = ImageFile._safe_read(self.fp, length)
+                if cid[1:2].islower():
+                    self.private_chunks.append((cid, s))
+
+            self.png.crc(cid, s)
+
+        #
+        # Copy relevant attributes from the PngStream.  An alternative
+        # would be to let the PngStream class modify these attributes
+        # directly, but that introduces circular references which are
+        # difficult to break if things go wrong in the decoder...
+        # (believe me, I've tried ;-)
+
+        self._mode = self.png.im_mode
+        self._size = self.png.im_size
+        self.info = self.png.im_info
+        self._text: dict[str, str | iTXt] | None = None
+        self.tile = self.png.im_tile
+        self.custom_mimetype = self.png.im_custom_mimetype
+        self.n_frames = self.png.im_n_frames or 1
+        self.default_image = self.info.get("default_image", False)
+
+        if self.png.im_palette:
+            rawmode, data = self.png.im_palette
+            self.palette = ImagePalette.raw(rawmode, data)
+
+        if cid == b"fdAT":
+            self.__prepare_idat = length - 4
+        else:
+            self.__prepare_idat = length  # used by load_prepare()
+
+        if self.png.im_n_frames is not None:
+            self._close_exclusive_fp_after_loading = False
+            self.png.save_rewind()
+            self.__rewind_idat = self.__prepare_idat
+            self.__rewind = self._fp.tell()
+            if self.default_image:
+                # IDAT chunk contains default image and not first animation frame
+                self.n_frames += 1
+            self._seek(0)
+        self.is_animated = self.n_frames > 1
+
+    @property
+    def text(self) -> dict[str, str | iTXt]:
+        # experimental
+        if self._text is None:
+            # iTxt, tEXt and zTXt chunks may appear at the end of the file
+            # So load the file to ensure that they are read
+            if self.is_animated:
+                frame = self.__frame
+                # for APNG, seek to the final frame before loading
+                self.seek(self.n_frames - 1)
+            self.load()
+            if self.is_animated:
+                self.seek(frame)
+        assert self._text is not None
+        return self._text
+
+    def verify(self) -> None:
+        """Verify PNG file"""
+
+        if self.fp is None:
+            msg = "verify must be called directly after open"
+            raise RuntimeError(msg)
+
+        # back up to beginning of IDAT block
+        self.fp.seek(self.tile[0][2] - 8)
+
+        assert self.png is not None
+        self.png.verify()
+        self.png.close()
+
+        if self._exclusive_fp:
+            self.fp.close()
+        self.fp = None
+
+    def seek(self, frame: int) -> None:
+        if not self._seek_check(frame):
+            return
+        if frame < self.__frame:
+            self._seek(0, True)
+
+        last_frame = self.__frame
+        for f in range(self.__frame + 1, frame + 1):
+            try:
+                self._seek(f)
+            except EOFError as e:
+                self.seek(last_frame)
+                msg = "no more images in APNG file"
+                raise EOFError(msg) from e
+
+    def _seek(self, frame: int, rewind: bool = False) -> None:
+        assert self.png is not None
+
+        self.dispose: _imaging.ImagingCore | None
+        dispose_extent = None
+        if frame == 0:
+            if rewind:
+                self._fp.seek(self.__rewind)
+                self.png.rewind()
+                self.__prepare_idat = self.__rewind_idat
+                self._im = None
+                self.info = self.png.im_info
+                self.tile = self.png.im_tile
+                self.fp = self._fp
+            self._prev_im = None
+            self.dispose = None
+            self.default_image = self.info.get("default_image", False)
+            self.dispose_op = self.info.get("disposal")
+            self.blend_op = self.info.get("blend")
+            dispose_extent = self.info.get("bbox")
+            self.__frame = 0
+        else:
+            if frame != self.__frame + 1:
+                msg = f"cannot seek to frame {frame}"
+                raise ValueError(msg)
+
+            # ensure previous frame was loaded
+            self.load()
+
+            if self.dispose:
+                self.im.paste(self.dispose, self.dispose_extent)
+            self._prev_im = self.im.copy()
+
+            self.fp = self._fp
+
+            # advance to the next frame
+            if self.__prepare_idat:
+                ImageFile._safe_read(self.fp, self.__prepare_idat)
+                self.__prepare_idat = 0
+            frame_start = False
+            while True:
+                self.fp.read(4)  # CRC
+
+                try:
+                    cid, pos, length = self.png.read()
+                except (struct.error, SyntaxError):
+                    break
+
+                if cid == b"IEND":
+                    msg = "No more images in APNG file"
+                    raise EOFError(msg)
+                if cid == b"fcTL":
+                    if frame_start:
+                        # there must be at least one fdAT chunk between fcTL chunks
+                        msg = "APNG missing frame data"
+                        raise SyntaxError(msg)
+                    frame_start = True
+
+                try:
+                    self.png.call(cid, pos, length)
+                except UnicodeDecodeError:
+                    break
+                except EOFError:
+                    if cid == b"fdAT":
+                        length -= 4
+                        if frame_start:
+                            self.__prepare_idat = length
+                            break
+                    ImageFile._safe_read(self.fp, length)
+                except AttributeError:
+                    logger.debug("%r %s %s (unknown)", cid, pos, length)
+                    ImageFile._safe_read(self.fp, length)
+
+            self.__frame = frame
+            self.tile = self.png.im_tile
+            self.dispose_op = self.info.get("disposal")
+            self.blend_op = self.info.get("blend")
+            dispose_extent = self.info.get("bbox")
+
+            if not self.tile:
+                msg = "image not found in APNG frame"
+                raise EOFError(msg)
+        if dispose_extent:
+            self.dispose_extent: tuple[float, float, float, float] = dispose_extent
+
+        # setup frame disposal (actual disposal done when needed in the next _seek())
+        if self._prev_im is None and self.dispose_op == Disposal.OP_PREVIOUS:
+            self.dispose_op = Disposal.OP_BACKGROUND
+
+        self.dispose = None
+        if self.dispose_op == Disposal.OP_PREVIOUS:
+            if self._prev_im:
+                self.dispose = self._prev_im.copy()
+                self.dispose = self._crop(self.dispose, self.dispose_extent)
+        elif self.dispose_op == Disposal.OP_BACKGROUND:
+            self.dispose = Image.core.fill(self.mode, self.size)
+            self.dispose = self._crop(self.dispose, self.dispose_extent)
+
+    def tell(self) -> int:
+        return self.__frame
+
+    def load_prepare(self) -> None:
+        """internal: prepare to read PNG file"""
+
+        if self.info.get("interlace"):
+            self.decoderconfig = self.decoderconfig + (1,)
+
+        self.__idat = self.__prepare_idat  # used by load_read()
+        ImageFile.ImageFile.load_prepare(self)
+
+    def load_read(self, read_bytes: int) -> bytes:
+        """internal: read more image data"""
+
+        assert self.png is not None
+        while self.__idat == 0:
+            # end of chunk, skip forward to next one
+
+            self.fp.read(4)  # CRC
+
+            cid, pos, length = self.png.read()
+
+            if cid not in [b"IDAT", b"DDAT", b"fdAT"]:
+                self.png.push(cid, pos, length)
+                return b""
+
+            if cid == b"fdAT":
+                try:
+                    self.png.call(cid, pos, length)
+                except EOFError:
+                    pass
+                self.__idat = length - 4  # sequence_num has already been read
+            else:
+                self.__idat = length  # empty chunks are allowed
+
+        # read more data from this chunk
+        if read_bytes <= 0:
+            read_bytes = self.__idat
+        else:
+            read_bytes = min(read_bytes, self.__idat)
+
+        self.__idat = self.__idat - read_bytes
+
+        return self.fp.read(read_bytes)
+
+    def load_end(self) -> None:
+        """internal: finished reading image data"""
+        assert self.png is not None
+        if self.__idat != 0:
+            self.fp.read(self.__idat)
+        while True:
+            self.fp.read(4)  # CRC
+
+            try:
+                cid, pos, length = self.png.read()
+            except (struct.error, SyntaxError):
+                break
+
+            if cid == b"IEND":
+                break
+            elif cid == b"fcTL" and self.is_animated:
+                # start of the next frame, stop reading
+                self.__prepare_idat = 0
+                self.png.push(cid, pos, length)
+                break
+
+            try:
+                self.png.call(cid, pos, length)
+            except UnicodeDecodeError:
+                break
+            except EOFError:
+                if cid == b"fdAT":
+                    length -= 4
+                try:
+                    ImageFile._safe_read(self.fp, length)
+                except OSError as e:
+                    if ImageFile.LOAD_TRUNCATED_IMAGES:
+                        break
+                    else:
+                        raise e
+            except AttributeError:
+                logger.debug("%r %s %s (unknown)", cid, pos, length)
+                s = ImageFile._safe_read(self.fp, length)
+                if cid[1:2].islower():
+                    self.private_chunks.append((cid, s, True))
+        self._text = self.png.im_text
+        if not self.is_animated:
+            self.png.close()
+            self.png = None
+        else:
+            if self._prev_im and self.blend_op == Blend.OP_OVER:
+                updated = self._crop(self.im, self.dispose_extent)
+                if self.im.mode == "RGB" and "transparency" in self.info:
+                    mask = updated.convert_transparent(
+                        "RGBA", self.info["transparency"]
+                    )
+                else:
+                    if self.im.mode == "P" and "transparency" in self.info:
+                        t = self.info["transparency"]
+                        if isinstance(t, bytes):
+                            updated.putpalettealphas(t)
+                        elif isinstance(t, int):
+                            updated.putpalettealpha(t)
+                    mask = updated.convert("RGBA")
+                self._prev_im.paste(updated, self.dispose_extent, mask)
+                self.im = self._prev_im
+
+    def _getexif(self) -> dict[int, Any] | None:
+        if "exif" not in self.info:
+            self.load()
+        if "exif" not in self.info and "Raw profile type exif" not in self.info:
+            return None
+        return self.getexif()._get_merged_dict()
+
+    def getexif(self) -> Image.Exif:
+        if "exif" not in self.info:
+            self.load()
+
+        return super().getexif()
+
+
+# --------------------------------------------------------------------
+# PNG writer
+
+_OUTMODES = {
+    # supported PIL modes, and corresponding rawmode, bit depth and color type
+    "1": ("1", b"\x01", b"\x00"),
+    "L;1": ("L;1", b"\x01", b"\x00"),
+    "L;2": ("L;2", b"\x02", b"\x00"),
+    "L;4": ("L;4", b"\x04", b"\x00"),
+    "L": ("L", b"\x08", b"\x00"),
+    "LA": ("LA", b"\x08", b"\x04"),
+    "I": ("I;16B", b"\x10", b"\x00"),
+    "I;16": ("I;16B", b"\x10", b"\x00"),
+    "I;16B": ("I;16B", b"\x10", b"\x00"),
+    "P;1": ("P;1", b"\x01", b"\x03"),
+    "P;2": ("P;2", b"\x02", b"\x03"),
+    "P;4": ("P;4", b"\x04", b"\x03"),
+    "P": ("P", b"\x08", b"\x03"),
+    "RGB": ("RGB", b"\x08", b"\x02"),
+    "RGBA": ("RGBA", b"\x08", b"\x06"),
+}
+
+
+def putchunk(fp: IO[bytes], cid: bytes, *data: bytes) -> None:
+    """Write a PNG chunk (including CRC field)"""
+
+    byte_data = b"".join(data)
+
+    fp.write(o32(len(byte_data)) + cid)
+    fp.write(byte_data)
+    crc = _crc32(byte_data, _crc32(cid))
+    fp.write(o32(crc))
+
+
+class _idat:
+    # wrap output from the encoder in IDAT chunks
+
+    def __init__(self, fp: IO[bytes], chunk: Callable[..., None]) -> None:
+        self.fp = fp
+        self.chunk = chunk
+
+    def write(self, data: bytes) -> None:
+        self.chunk(self.fp, b"IDAT", data)
+
+
+class _fdat:
+    # wrap encoder output in fdAT chunks
+
+    def __init__(self, fp: IO[bytes], chunk: Callable[..., None], seq_num: int) -> None:
+        self.fp = fp
+        self.chunk = chunk
+        self.seq_num = seq_num
+
+    def write(self, data: bytes) -> None:
+        self.chunk(self.fp, b"fdAT", o32(self.seq_num), data)
+        self.seq_num += 1
+
+
+class _Frame(NamedTuple):
+    im: Image.Image
+    bbox: tuple[int, int, int, int] | None
+    encoderinfo: dict[str, Any]
+
+
+def _write_multiple_frames(
+    im: Image.Image,
+    fp: IO[bytes],
+    chunk: Callable[..., None],
+    mode: str,
+    rawmode: str,
+    default_image: Image.Image | None,
+    append_images: list[Image.Image],
+) -> Image.Image | None:
+    duration = im.encoderinfo.get("duration")
+    loop = im.encoderinfo.get("loop", im.info.get("loop", 0))
+    disposal = im.encoderinfo.get("disposal", im.info.get("disposal", Disposal.OP_NONE))
+    blend = im.encoderinfo.get("blend", im.info.get("blend", Blend.OP_SOURCE))
+
+    if default_image:
+        chain = itertools.chain(append_images)
+    else:
+        chain = itertools.chain([im], append_images)
+
+    im_frames: list[_Frame] = []
+    frame_count = 0
+    for im_seq in chain:
+        for im_frame in ImageSequence.Iterator(im_seq):
+            if im_frame.mode == mode:
+                im_frame = im_frame.copy()
+            else:
+                im_frame = im_frame.convert(mode)
+            encoderinfo = im.encoderinfo.copy()
+            if isinstance(duration, (list, tuple)):
+                encoderinfo["duration"] = duration[frame_count]
+            elif duration is None and "duration" in im_frame.info:
+                encoderinfo["duration"] = im_frame.info["duration"]
+            if isinstance(disposal, (list, tuple)):
+                encoderinfo["disposal"] = disposal[frame_count]
+            if isinstance(blend, (list, tuple)):
+                encoderinfo["blend"] = blend[frame_count]
+            frame_count += 1
+
+            if im_frames:
+                previous = im_frames[-1]
+                prev_disposal = previous.encoderinfo.get("disposal")
+                prev_blend = previous.encoderinfo.get("blend")
+                if prev_disposal == Disposal.OP_PREVIOUS and len(im_frames) < 2:
+                    prev_disposal = Disposal.OP_BACKGROUND
+
+                if prev_disposal == Disposal.OP_BACKGROUND:
+                    base_im = previous.im.copy()
+                    dispose = Image.core.fill("RGBA", im.size, (0, 0, 0, 0))
+                    bbox = previous.bbox
+                    if bbox:
+                        dispose = dispose.crop(bbox)
+                    else:
+                        bbox = (0, 0) + im.size
+                    base_im.paste(dispose, bbox)
+                elif prev_disposal == Disposal.OP_PREVIOUS:
+                    base_im = im_frames[-2].im
+                else:
+                    base_im = previous.im
+                delta = ImageChops.subtract_modulo(
+                    im_frame.convert("RGBA"), base_im.convert("RGBA")
+                )
+                bbox = delta.getbbox(alpha_only=False)
+                if (
+                    not bbox
+                    and prev_disposal == encoderinfo.get("disposal")
+                    and prev_blend == encoderinfo.get("blend")
+                    and "duration" in encoderinfo
+                ):
+                    previous.encoderinfo["duration"] += encoderinfo["duration"]
+                    continue
+            else:
+                bbox = None
+            im_frames.append(_Frame(im_frame, bbox, encoderinfo))
+
+    if len(im_frames) == 1 and not default_image:
+        return im_frames[0].im
+
+    # animation control
+    chunk(
+        fp,
+        b"acTL",
+        o32(len(im_frames)),  # 0: num_frames
+        o32(loop),  # 4: num_plays
+    )
+
+    # default image IDAT (if it exists)
+    if default_image:
+        if im.mode != mode:
+            im = im.convert(mode)
+        ImageFile._save(
+            im,
+            cast(IO[bytes], _idat(fp, chunk)),
+            [ImageFile._Tile("zip", (0, 0) + im.size, 0, rawmode)],
+        )
+
+    seq_num = 0
+    for frame, frame_data in enumerate(im_frames):
+        im_frame = frame_data.im
+        if not frame_data.bbox:
+            bbox = (0, 0) + im_frame.size
+        else:
+            bbox = frame_data.bbox
+            im_frame = im_frame.crop(bbox)
+        size = im_frame.size
+        encoderinfo = frame_data.encoderinfo
+        frame_duration = int(round(encoderinfo.get("duration", 0)))
+        frame_disposal = encoderinfo.get("disposal", disposal)
+        frame_blend = encoderinfo.get("blend", blend)
+        # frame control
+        chunk(
+            fp,
+            b"fcTL",
+            o32(seq_num),  # sequence_number
+            o32(size[0]),  # width
+            o32(size[1]),  # height
+            o32(bbox[0]),  # x_offset
+            o32(bbox[1]),  # y_offset
+            o16(frame_duration),  # delay_numerator
+            o16(1000),  # delay_denominator
+            o8(frame_disposal),  # dispose_op
+            o8(frame_blend),  # blend_op
+        )
+        seq_num += 1
+        # frame data
+        if frame == 0 and not default_image:
+            # first frame must be in IDAT chunks for backwards compatibility
+            ImageFile._save(
+                im_frame,
+                cast(IO[bytes], _idat(fp, chunk)),
+                [ImageFile._Tile("zip", (0, 0) + im_frame.size, 0, rawmode)],
+            )
+        else:
+            fdat_chunks = _fdat(fp, chunk, seq_num)
+            ImageFile._save(
+                im_frame,
+                cast(IO[bytes], fdat_chunks),
+                [ImageFile._Tile("zip", (0, 0) + im_frame.size, 0, rawmode)],
+            )
+            seq_num = fdat_chunks.seq_num
+    return None
+
+
+def _save_all(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
+    _save(im, fp, filename, save_all=True)
+
+
+def _save(
+    im: Image.Image,
+    fp: IO[bytes],
+    filename: str | bytes,
+    chunk: Callable[..., None] = putchunk,
+    save_all: bool = False,
+) -> None:
+    # save an image to disk (called by the save method)
+
+    if save_all:
+        default_image = im.encoderinfo.get(
+            "default_image", im.info.get("default_image")
+        )
+        modes = set()
+        sizes = set()
+        append_images = im.encoderinfo.get("append_images", [])
+        for im_seq in itertools.chain([im], append_images):
+            for im_frame in ImageSequence.Iterator(im_seq):
+                modes.add(im_frame.mode)
+                sizes.add(im_frame.size)
+        for mode in ("RGBA", "RGB", "P"):
+            if mode in modes:
+                break
+        else:
+            mode = modes.pop()
+        size = tuple(max(frame_size[i] for frame_size in sizes) for i in range(2))
+    else:
+        size = im.size
+        mode = im.mode
+
+    outmode = mode
+    if mode == "P":
+        #
+        # attempt to minimize storage requirements for palette images
+        if "bits" in im.encoderinfo:
+            # number of bits specified by user
+            colors = min(1 << im.encoderinfo["bits"], 256)
+        else:
+            # check palette contents
+            if im.palette:
+                colors = max(min(len(im.palette.getdata()[1]) // 3, 256), 1)
+            else:
+                colors = 256
+
+        if colors <= 16:
+            if colors <= 2:
+                bits = 1
+            elif colors <= 4:
+                bits = 2
+            else:
+                bits = 4
+            outmode += f";{bits}"
+
+    # encoder options
+    im.encoderconfig = (
+        im.encoderinfo.get("optimize", False),
+        im.encoderinfo.get("compress_level", -1),
+        im.encoderinfo.get("compress_type", -1),
+        im.encoderinfo.get("dictionary", b""),
+    )
+
+    # get the corresponding PNG mode
+    try:
+        rawmode, bit_depth, color_type = _OUTMODES[outmode]
+    except KeyError as e:
+        msg = f"cannot write mode {mode} as PNG"
+        raise OSError(msg) from e
+
+    #
+    # write minimal PNG file
+
+    fp.write(_MAGIC)
+
+    chunk(
+        fp,
+        b"IHDR",
+        o32(size[0]),  # 0: size
+        o32(size[1]),
+        bit_depth,
+        color_type,
+        b"\0",  # 10: compression
+        b"\0",  # 11: filter category
+        b"\0",  # 12: interlace flag
+    )
+
+    chunks = [b"cHRM", b"gAMA", b"sBIT", b"sRGB", b"tIME"]
+
+    icc = im.encoderinfo.get("icc_profile", im.info.get("icc_profile"))
+    if icc:
+        # ICC profile
+        # according to PNG spec, the iCCP chunk contains:
+        # Profile name  1-79 bytes (character string)
+        # Null separator        1 byte (null character)
+        # Compression method    1 byte (0)
+        # Compressed profile    n bytes (zlib with deflate compression)
+        name = b"ICC Profile"
+        data = name + b"\0\0" + zlib.compress(icc)
+        chunk(fp, b"iCCP", data)
+
+        # You must either have sRGB or iCCP.
+        # Disallow sRGB chunks when an iCCP-chunk has been emitted.
+        chunks.remove(b"sRGB")
+
+    info = im.encoderinfo.get("pnginfo")
+    if info:
+        chunks_multiple_allowed = [b"sPLT", b"iTXt", b"tEXt", b"zTXt"]
+        for info_chunk in info.chunks:
+            cid, data = info_chunk[:2]
+            if cid in chunks:
+                chunks.remove(cid)
+                chunk(fp, cid, data)
+            elif cid in chunks_multiple_allowed:
+                chunk(fp, cid, data)
+            elif cid[1:2].islower():
+                # Private chunk
+                after_idat = len(info_chunk) == 3 and info_chunk[2]
+                if not after_idat:
+                    chunk(fp, cid, data)
+
+    if im.mode == "P":
+        palette_byte_number = colors * 3
+        palette_bytes = im.im.getpalette("RGB")[:palette_byte_number]
+        while len(palette_bytes) < palette_byte_number:
+            palette_bytes += b"\0"
+        chunk(fp, b"PLTE", palette_bytes)
+
+    transparency = im.encoderinfo.get("transparency", im.info.get("transparency", None))
+
+    if transparency or transparency == 0:
+        if im.mode == "P":
+            # limit to actual palette size
+            alpha_bytes = colors
+            if isinstance(transparency, bytes):
+                chunk(fp, b"tRNS", transparency[:alpha_bytes])
+            else:
+                transparency = max(0, min(255, transparency))
+                alpha = b"\xFF" * transparency + b"\0"
+                chunk(fp, b"tRNS", alpha[:alpha_bytes])
+        elif im.mode in ("1", "L", "I", "I;16"):
+            transparency = max(0, min(65535, transparency))
+            chunk(fp, b"tRNS", o16(transparency))
+        elif im.mode == "RGB":
+            red, green, blue = transparency
+            chunk(fp, b"tRNS", o16(red) + o16(green) + o16(blue))
+        else:
+            if "transparency" in im.encoderinfo:
+                # don't bother with transparency if it's an RGBA
+                # and it's in the info dict. It's probably just stale.
+                msg = "cannot use transparency for this mode"
+                raise OSError(msg)
+    else:
+        if im.mode == "P" and im.im.getpalettemode() == "RGBA":
+            alpha = im.im.getpalette("RGBA", "A")
+            alpha_bytes = colors
+            chunk(fp, b"tRNS", alpha[:alpha_bytes])
+
+    dpi = im.encoderinfo.get("dpi")
+    if dpi:
+        chunk(
+            fp,
+            b"pHYs",
+            o32(int(dpi[0] / 0.0254 + 0.5)),
+            o32(int(dpi[1] / 0.0254 + 0.5)),
+            b"\x01",
+        )
+
+    if info:
+        chunks = [b"bKGD", b"hIST"]
+        for info_chunk in info.chunks:
+            cid, data = info_chunk[:2]
+            if cid in chunks:
+                chunks.remove(cid)
+                chunk(fp, cid, data)
+
+    exif = im.encoderinfo.get("exif")
+    if exif:
+        if isinstance(exif, Image.Exif):
+            exif = exif.tobytes(8)
+        if exif.startswith(b"Exif\x00\x00"):
+            exif = exif[6:]
+        chunk(fp, b"eXIf", exif)
+
+    single_im: Image.Image | None = im
+    if save_all:
+        single_im = _write_multiple_frames(
+            im, fp, chunk, mode, rawmode, default_image, append_images
+        )
+    if single_im:
+        ImageFile._save(
+            single_im,
+            cast(IO[bytes], _idat(fp, chunk)),
+            [ImageFile._Tile("zip", (0, 0) + single_im.size, 0, rawmode)],
+        )
+
+    if info:
+        for info_chunk in info.chunks:
+            cid, data = info_chunk[:2]
+            if cid[1:2].islower():
+                # Private chunk
+                after_idat = len(info_chunk) == 3 and info_chunk[2]
+                if after_idat:
+                    chunk(fp, cid, data)
+
+    chunk(fp, b"IEND", b"")
+
+    if hasattr(fp, "flush"):
+        fp.flush()
+
+
+# --------------------------------------------------------------------
+# PNG chunk converter
+
+
+def getchunks(im: Image.Image, **params: Any) -> list[tuple[bytes, bytes, bytes]]:
+    """Return a list of PNG chunks representing this image."""
+    from io import BytesIO
+
+    chunks = []
+
+    def append(fp: IO[bytes], cid: bytes, *data: bytes) -> None:
+        byte_data = b"".join(data)
+        crc = o32(_crc32(byte_data, _crc32(cid)))
+        chunks.append((cid, byte_data, crc))
+
+    fp = BytesIO()
+
+    try:
+        im.encoderinfo = params
+        _save(im, fp, "", append)
+    finally:
+        del im.encoderinfo
+
+    return chunks
+
+
+# --------------------------------------------------------------------
+# Registry
+
+Image.register_open(PngImageFile.format, PngImageFile, _accept)
+Image.register_save(PngImageFile.format, _save)
+Image.register_save_all(PngImageFile.format, _save_all)
+
+Image.register_extensions(PngImageFile.format, [".png", ".apng"])
+
+Image.register_mime(PngImageFile.format, "image/png")