diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/PIL/Jpeg2KImagePlugin.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/PIL/Jpeg2KImagePlugin.py | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/PIL/Jpeg2KImagePlugin.py b/.venv/lib/python3.12/site-packages/PIL/Jpeg2KImagePlugin.py new file mode 100644 index 00000000..67828358 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/PIL/Jpeg2KImagePlugin.py @@ -0,0 +1,443 @@ +# +# The Python Imaging Library +# $Id$ +# +# JPEG2000 file handling +# +# History: +# 2014-03-12 ajh Created +# 2021-06-30 rogermb Extract dpi information from the 'resc' header box +# +# Copyright (c) 2014 Coriolis Systems Limited +# Copyright (c) 2014 Alastair Houghton +# +# See the README file for information on usage and redistribution. +# +from __future__ import annotations + +import io +import os +import struct +from collections.abc import Callable +from typing import IO, cast + +from . import Image, ImageFile, ImagePalette, _binary + + +class BoxReader: + """ + A small helper class to read fields stored in JPEG2000 header boxes + and to easily step into and read sub-boxes. + """ + + def __init__(self, fp: IO[bytes], length: int = -1) -> None: + self.fp = fp + self.has_length = length >= 0 + self.length = length + self.remaining_in_box = -1 + + def _can_read(self, num_bytes: int) -> bool: + if self.has_length and self.fp.tell() + num_bytes > self.length: + # Outside box: ensure we don't read past the known file length + return False + if self.remaining_in_box >= 0: + # Inside box contents: ensure read does not go past box boundaries + return num_bytes <= self.remaining_in_box + else: + return True # No length known, just read + + def _read_bytes(self, num_bytes: int) -> bytes: + if not self._can_read(num_bytes): + msg = "Not enough data in header" + raise SyntaxError(msg) + + data = self.fp.read(num_bytes) + if len(data) < num_bytes: + msg = f"Expected to read {num_bytes} bytes but only got {len(data)}." + raise OSError(msg) + + if self.remaining_in_box > 0: + self.remaining_in_box -= num_bytes + return data + + def read_fields(self, field_format: str) -> tuple[int | bytes, ...]: + size = struct.calcsize(field_format) + data = self._read_bytes(size) + return struct.unpack(field_format, data) + + def read_boxes(self) -> BoxReader: + size = self.remaining_in_box + data = self._read_bytes(size) + return BoxReader(io.BytesIO(data), size) + + def has_next_box(self) -> bool: + if self.has_length: + return self.fp.tell() + self.remaining_in_box < self.length + else: + return True + + def next_box_type(self) -> bytes: + # Skip the rest of the box if it has not been read + if self.remaining_in_box > 0: + self.fp.seek(self.remaining_in_box, os.SEEK_CUR) + self.remaining_in_box = -1 + + # Read the length and type of the next box + lbox, tbox = cast(tuple[int, bytes], self.read_fields(">I4s")) + if lbox == 1: + lbox = cast(int, self.read_fields(">Q")[0]) + hlen = 16 + else: + hlen = 8 + + if lbox < hlen or not self._can_read(lbox - hlen): + msg = "Invalid header length" + raise SyntaxError(msg) + + self.remaining_in_box = lbox - hlen + return tbox + + +def _parse_codestream(fp: IO[bytes]) -> tuple[tuple[int, int], str]: + """Parse the JPEG 2000 codestream to extract the size and component + count from the SIZ marker segment, returning a PIL (size, mode) tuple.""" + + hdr = fp.read(2) + lsiz = _binary.i16be(hdr) + siz = hdr + fp.read(lsiz - 2) + lsiz, rsiz, xsiz, ysiz, xosiz, yosiz, _, _, _, _, csiz = struct.unpack_from( + ">HHIIIIIIIIH", siz + ) + + size = (xsiz - xosiz, ysiz - yosiz) + if csiz == 1: + ssiz = struct.unpack_from(">B", siz, 38) + if (ssiz[0] & 0x7F) + 1 > 8: + mode = "I;16" + else: + mode = "L" + elif csiz == 2: + mode = "LA" + elif csiz == 3: + mode = "RGB" + elif csiz == 4: + mode = "RGBA" + else: + msg = "unable to determine J2K image mode" + raise SyntaxError(msg) + + return size, mode + + +def _res_to_dpi(num: int, denom: int, exp: int) -> float | None: + """Convert JPEG2000's (numerator, denominator, exponent-base-10) resolution, + calculated as (num / denom) * 10^exp and stored in dots per meter, + to floating-point dots per inch.""" + if denom == 0: + return None + return (254 * num * (10**exp)) / (10000 * denom) + + +def _parse_jp2_header( + fp: IO[bytes], +) -> tuple[ + tuple[int, int], + str, + str | None, + tuple[float, float] | None, + ImagePalette.ImagePalette | None, +]: + """Parse the JP2 header box to extract size, component count, + color space information, and optionally DPI information, + returning a (size, mode, mimetype, dpi) tuple.""" + + # Find the JP2 header box + reader = BoxReader(fp) + header = None + mimetype = None + while reader.has_next_box(): + tbox = reader.next_box_type() + + if tbox == b"jp2h": + header = reader.read_boxes() + break + elif tbox == b"ftyp": + if reader.read_fields(">4s")[0] == b"jpx ": + mimetype = "image/jpx" + assert header is not None + + size = None + mode = None + bpc = None + nc = None + dpi = None # 2-tuple of DPI info, or None + palette = None + + while header.has_next_box(): + tbox = header.next_box_type() + + if tbox == b"ihdr": + height, width, nc, bpc = header.read_fields(">IIHB") + assert isinstance(height, int) + assert isinstance(width, int) + assert isinstance(bpc, int) + size = (width, height) + if nc == 1 and (bpc & 0x7F) > 8: + mode = "I;16" + elif nc == 1: + mode = "L" + elif nc == 2: + mode = "LA" + elif nc == 3: + mode = "RGB" + elif nc == 4: + mode = "RGBA" + elif tbox == b"colr" and nc == 4: + meth, _, _, enumcs = header.read_fields(">BBBI") + if meth == 1 and enumcs == 12: + mode = "CMYK" + elif tbox == b"pclr" and mode in ("L", "LA"): + ne, npc = header.read_fields(">HB") + assert isinstance(ne, int) + assert isinstance(npc, int) + max_bitdepth = 0 + for bitdepth in header.read_fields(">" + ("B" * npc)): + assert isinstance(bitdepth, int) + if bitdepth > max_bitdepth: + max_bitdepth = bitdepth + if max_bitdepth <= 8: + palette = ImagePalette.ImagePalette("RGBA" if npc == 4 else "RGB") + for i in range(ne): + color: list[int] = [] + for value in header.read_fields(">" + ("B" * npc)): + assert isinstance(value, int) + color.append(value) + palette.getcolor(tuple(color)) + mode = "P" if mode == "L" else "PA" + elif tbox == b"res ": + res = header.read_boxes() + while res.has_next_box(): + tres = res.next_box_type() + if tres == b"resc": + vrcn, vrcd, hrcn, hrcd, vrce, hrce = res.read_fields(">HHHHBB") + assert isinstance(vrcn, int) + assert isinstance(vrcd, int) + assert isinstance(hrcn, int) + assert isinstance(hrcd, int) + assert isinstance(vrce, int) + assert isinstance(hrce, int) + hres = _res_to_dpi(hrcn, hrcd, hrce) + vres = _res_to_dpi(vrcn, vrcd, vrce) + if hres is not None and vres is not None: + dpi = (hres, vres) + break + + if size is None or mode is None: + msg = "Malformed JP2 header" + raise SyntaxError(msg) + + return size, mode, mimetype, dpi, palette + + +## +# Image plugin for JPEG2000 images. + + +class Jpeg2KImageFile(ImageFile.ImageFile): + format = "JPEG2000" + format_description = "JPEG 2000 (ISO 15444)" + + def _open(self) -> None: + sig = self.fp.read(4) + if sig == b"\xff\x4f\xff\x51": + self.codec = "j2k" + self._size, self._mode = _parse_codestream(self.fp) + self._parse_comment() + else: + sig = sig + self.fp.read(8) + + if sig == b"\x00\x00\x00\x0cjP \x0d\x0a\x87\x0a": + self.codec = "jp2" + header = _parse_jp2_header(self.fp) + self._size, self._mode, self.custom_mimetype, dpi, self.palette = header + if dpi is not None: + self.info["dpi"] = dpi + if self.fp.read(12).endswith(b"jp2c\xff\x4f\xff\x51"): + hdr = self.fp.read(2) + length = _binary.i16be(hdr) + self.fp.seek(length - 2, os.SEEK_CUR) + self._parse_comment() + else: + msg = "not a JPEG 2000 file" + raise SyntaxError(msg) + + self._reduce = 0 + self.layers = 0 + + fd = -1 + length = -1 + + try: + fd = self.fp.fileno() + length = os.fstat(fd).st_size + except Exception: + fd = -1 + try: + pos = self.fp.tell() + self.fp.seek(0, io.SEEK_END) + length = self.fp.tell() + self.fp.seek(pos) + except Exception: + length = -1 + + self.tile = [ + ImageFile._Tile( + "jpeg2k", + (0, 0) + self.size, + 0, + (self.codec, self._reduce, self.layers, fd, length), + ) + ] + + def _parse_comment(self) -> None: + while True: + marker = self.fp.read(2) + if not marker: + break + typ = marker[1] + if typ in (0x90, 0xD9): + # Start of tile or end of codestream + break + hdr = self.fp.read(2) + length = _binary.i16be(hdr) + if typ == 0x64: + # Comment + self.info["comment"] = self.fp.read(length - 2)[2:] + break + else: + self.fp.seek(length - 2, os.SEEK_CUR) + + @property # type: ignore[override] + def reduce( + self, + ) -> ( + Callable[[int | tuple[int, int], tuple[int, int, int, int] | None], Image.Image] + | int + ): + # https://github.com/python-pillow/Pillow/issues/4343 found that the + # new Image 'reduce' method was shadowed by this plugin's 'reduce' + # property. This attempts to allow for both scenarios + return self._reduce or super().reduce + + @reduce.setter + def reduce(self, value: int) -> None: + self._reduce = value + + def load(self) -> Image.core.PixelAccess | None: + if self.tile and self._reduce: + power = 1 << self._reduce + adjust = power >> 1 + self._size = ( + int((self.size[0] + adjust) / power), + int((self.size[1] + adjust) / power), + ) + + # Update the reduce and layers settings + t = self.tile[0] + assert isinstance(t[3], tuple) + t3 = (t[3][0], self._reduce, self.layers, t[3][3], t[3][4]) + self.tile = [ImageFile._Tile(t[0], (0, 0) + self.size, t[2], t3)] + + return ImageFile.ImageFile.load(self) + + +def _accept(prefix: bytes) -> bool: + return ( + prefix[:4] == b"\xff\x4f\xff\x51" + or prefix[:12] == b"\x00\x00\x00\x0cjP \x0d\x0a\x87\x0a" + ) + + +# ------------------------------------------------------------ +# Save support + + +def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None: + # Get the keyword arguments + info = im.encoderinfo + + if isinstance(filename, str): + filename = filename.encode() + if filename.endswith(b".j2k") or info.get("no_jp2", False): + kind = "j2k" + else: + kind = "jp2" + + offset = info.get("offset", None) + tile_offset = info.get("tile_offset", None) + tile_size = info.get("tile_size", None) + quality_mode = info.get("quality_mode", "rates") + quality_layers = info.get("quality_layers", None) + if quality_layers is not None and not ( + isinstance(quality_layers, (list, tuple)) + and all( + isinstance(quality_layer, (int, float)) for quality_layer in quality_layers + ) + ): + msg = "quality_layers must be a sequence of numbers" + raise ValueError(msg) + + num_resolutions = info.get("num_resolutions", 0) + cblk_size = info.get("codeblock_size", None) + precinct_size = info.get("precinct_size", None) + irreversible = info.get("irreversible", False) + progression = info.get("progression", "LRCP") + cinema_mode = info.get("cinema_mode", "no") + mct = info.get("mct", 0) + signed = info.get("signed", False) + comment = info.get("comment") + if isinstance(comment, str): + comment = comment.encode() + plt = info.get("plt", False) + + fd = -1 + if hasattr(fp, "fileno"): + try: + fd = fp.fileno() + except Exception: + fd = -1 + + im.encoderconfig = ( + offset, + tile_offset, + tile_size, + quality_mode, + quality_layers, + num_resolutions, + cblk_size, + precinct_size, + irreversible, + progression, + cinema_mode, + mct, + signed, + fd, + comment, + plt, + ) + + ImageFile._save(im, fp, [ImageFile._Tile("jpeg2k", (0, 0) + im.size, 0, kind)]) + + +# ------------------------------------------------------------ +# Registry stuff + + +Image.register_open(Jpeg2KImageFile.format, Jpeg2KImageFile, _accept) +Image.register_save(Jpeg2KImageFile.format, _save) + +Image.register_extensions( + Jpeg2KImageFile.format, [".jp2", ".j2k", ".jpc", ".jpf", ".jpx", ".j2c"] +) + +Image.register_mime(Jpeg2KImageFile.format, "image/jp2") |