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Diffstat (limited to '.venv/lib/python3.12/site-packages/PIL/MspImagePlugin.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/PIL/MspImagePlugin.py | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/PIL/MspImagePlugin.py b/.venv/lib/python3.12/site-packages/PIL/MspImagePlugin.py new file mode 100644 index 00000000..ef6ae87f --- /dev/null +++ b/.venv/lib/python3.12/site-packages/PIL/MspImagePlugin.py @@ -0,0 +1,200 @@ +# +# The Python Imaging Library. +# +# MSP file handling +# +# This is the format used by the Paint program in Windows 1 and 2. +# +# History: +# 95-09-05 fl Created +# 97-01-03 fl Read/write MSP images +# 17-02-21 es Fixed RLE interpretation +# +# Copyright (c) Secret Labs AB 1997. +# Copyright (c) Fredrik Lundh 1995-97. +# Copyright (c) Eric Soroos 2017. +# +# See the README file for information on usage and redistribution. +# +# More info on this format: https://archive.org/details/gg243631 +# Page 313: +# Figure 205. Windows Paint Version 1: "DanM" Format +# Figure 206. Windows Paint Version 2: "LinS" Format. Used in Windows V2.03 +# +# See also: https://www.fileformat.info/format/mspaint/egff.htm +from __future__ import annotations + +import io +import struct +from typing import IO + +from . import Image, ImageFile +from ._binary import i16le as i16 +from ._binary import o16le as o16 + +# +# read MSP files + + +def _accept(prefix: bytes) -> bool: + return prefix[:4] in [b"DanM", b"LinS"] + + +## +# Image plugin for Windows MSP images. This plugin supports both +# uncompressed (Windows 1.0). + + +class MspImageFile(ImageFile.ImageFile): + format = "MSP" + format_description = "Windows Paint" + + def _open(self) -> None: + # Header + assert self.fp is not None + + s = self.fp.read(32) + if not _accept(s): + msg = "not an MSP file" + raise SyntaxError(msg) + + # Header checksum + checksum = 0 + for i in range(0, 32, 2): + checksum = checksum ^ i16(s, i) + if checksum != 0: + msg = "bad MSP checksum" + raise SyntaxError(msg) + + self._mode = "1" + self._size = i16(s, 4), i16(s, 6) + + if s[:4] == b"DanM": + self.tile = [ImageFile._Tile("raw", (0, 0) + self.size, 32, "1")] + else: + self.tile = [ImageFile._Tile("MSP", (0, 0) + self.size, 32)] + + +class MspDecoder(ImageFile.PyDecoder): + # The algo for the MSP decoder is from + # https://www.fileformat.info/format/mspaint/egff.htm + # cc-by-attribution -- That page references is taken from the + # Encyclopedia of Graphics File Formats and is licensed by + # O'Reilly under the Creative Common/Attribution license + # + # For RLE encoded files, the 32byte header is followed by a scan + # line map, encoded as one 16bit word of encoded byte length per + # line. + # + # NOTE: the encoded length of the line can be 0. This was not + # handled in the previous version of this encoder, and there's no + # mention of how to handle it in the documentation. From the few + # examples I've seen, I've assumed that it is a fill of the + # background color, in this case, white. + # + # + # Pseudocode of the decoder: + # Read a BYTE value as the RunType + # If the RunType value is zero + # Read next byte as the RunCount + # Read the next byte as the RunValue + # Write the RunValue byte RunCount times + # If the RunType value is non-zero + # Use this value as the RunCount + # Read and write the next RunCount bytes literally + # + # e.g.: + # 0x00 03 ff 05 00 01 02 03 04 + # would yield the bytes: + # 0xff ff ff 00 01 02 03 04 + # + # which are then interpreted as a bit packed mode '1' image + + _pulls_fd = True + + def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]: + assert self.fd is not None + + img = io.BytesIO() + blank_line = bytearray((0xFF,) * ((self.state.xsize + 7) // 8)) + try: + self.fd.seek(32) + rowmap = struct.unpack_from( + f"<{self.state.ysize}H", self.fd.read(self.state.ysize * 2) + ) + except struct.error as e: + msg = "Truncated MSP file in row map" + raise OSError(msg) from e + + for x, rowlen in enumerate(rowmap): + try: + if rowlen == 0: + img.write(blank_line) + continue + row = self.fd.read(rowlen) + if len(row) != rowlen: + msg = f"Truncated MSP file, expected {rowlen} bytes on row {x}" + raise OSError(msg) + idx = 0 + while idx < rowlen: + runtype = row[idx] + idx += 1 + if runtype == 0: + (runcount, runval) = struct.unpack_from("Bc", row, idx) + img.write(runval * runcount) + idx += 2 + else: + runcount = runtype + img.write(row[idx : idx + runcount]) + idx += runcount + + except struct.error as e: + msg = f"Corrupted MSP file in row {x}" + raise OSError(msg) from e + + self.set_as_raw(img.getvalue(), "1") + + return -1, 0 + + +Image.register_decoder("MSP", MspDecoder) + + +# +# write MSP files (uncompressed only) + + +def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None: + if im.mode != "1": + msg = f"cannot write mode {im.mode} as MSP" + raise OSError(msg) + + # create MSP header + header = [0] * 16 + + header[0], header[1] = i16(b"Da"), i16(b"nM") # version 1 + header[2], header[3] = im.size + header[4], header[5] = 1, 1 + header[6], header[7] = 1, 1 + header[8], header[9] = im.size + + checksum = 0 + for h in header: + checksum = checksum ^ h + header[12] = checksum # FIXME: is this the right field? + + # header + for h in header: + fp.write(o16(h)) + + # image body + ImageFile._save(im, fp, [ImageFile._Tile("raw", (0, 0) + im.size, 32, "1")]) + + +# +# registry + +Image.register_open(MspImageFile.format, MspImageFile, _accept) +Image.register_save(MspImageFile.format, _save) + +Image.register_extension(MspImageFile.format, ".msp") |