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#
# The Python Imaging Library.
# $Id$
#
# PCX file handling
#
# This format was originally used by ZSoft's popular PaintBrush
# program for the IBM PC. It is also supported by many MS-DOS and
# Windows applications, including the Windows PaintBrush program in
# Windows 3.
#
# history:
# 1995-09-01 fl Created
# 1996-05-20 fl Fixed RGB support
# 1997-01-03 fl Fixed 2-bit and 4-bit support
# 1999-02-03 fl Fixed 8-bit support (broken in 1.0b1)
# 1999-02-07 fl Added write support
# 2002-06-09 fl Made 2-bit and 4-bit support a bit more robust
# 2002-07-30 fl Seek from to current position, not beginning of file
# 2003-06-03 fl Extract DPI settings (info["dpi"])
#
# Copyright (c) 1997-2003 by Secret Labs AB.
# Copyright (c) 1995-2003 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#
import io
import logging
from . import Image, ImageFile, ImagePalette
from ._binary import i16le as i16
from ._binary import o8
from ._binary import o16le as o16
logger = logging.getLogger(__name__)
def _accept(prefix):
return prefix[0] == 10 and prefix[1] in [0, 2, 3, 5]
##
# Image plugin for Paintbrush images.
class PcxImageFile(ImageFile.ImageFile):
format = "PCX"
format_description = "Paintbrush"
def _open(self):
# header
s = self.fp.read(128)
if not _accept(s):
raise SyntaxError("not a PCX file")
# image
bbox = i16(s, 4), i16(s, 6), i16(s, 8) + 1, i16(s, 10) + 1
if bbox[2] <= bbox[0] or bbox[3] <= bbox[1]:
raise SyntaxError("bad PCX image size")
logger.debug("BBox: %s %s %s %s", *bbox)
# format
version = s[1]
bits = s[3]
planes = s[65]
provided_stride = i16(s, 66)
logger.debug(
"PCX version %s, bits %s, planes %s, stride %s",
version,
bits,
planes,
provided_stride,
)
self.info["dpi"] = i16(s, 12), i16(s, 14)
if bits == 1 and planes == 1:
mode = rawmode = "1"
elif bits == 1 and planes in (2, 4):
mode = "P"
rawmode = "P;%dL" % planes
self.palette = ImagePalette.raw("RGB", s[16:64])
elif version == 5 and bits == 8 and planes == 1:
mode = rawmode = "L"
# FIXME: hey, this doesn't work with the incremental loader !!!
self.fp.seek(-769, io.SEEK_END)
s = self.fp.read(769)
if len(s) == 769 and s[0] == 12:
# check if the palette is linear greyscale
for i in range(256):
if s[i * 3 + 1 : i * 3 + 4] != o8(i) * 3:
mode = rawmode = "P"
break
if mode == "P":
self.palette = ImagePalette.raw("RGB", s[1:])
self.fp.seek(128)
elif version == 5 and bits == 8 and planes == 3:
mode = "RGB"
rawmode = "RGB;L"
else:
raise OSError("unknown PCX mode")
self.mode = mode
self._size = bbox[2] - bbox[0], bbox[3] - bbox[1]
# Don't trust the passed in stride.
# Calculate the approximate position for ourselves.
# CVE-2020-35653
stride = (self._size[0] * bits + 7) // 8
# While the specification states that this must be even,
# not all images follow this
if provided_stride != stride:
stride += stride % 2
bbox = (0, 0) + self.size
logger.debug("size: %sx%s", *self.size)
self.tile = [("pcx", bbox, self.fp.tell(), (rawmode, planes * stride))]
# --------------------------------------------------------------------
# save PCX files
SAVE = {
# mode: (version, bits, planes, raw mode)
"1": (2, 1, 1, "1"),
"L": (5, 8, 1, "L"),
"P": (5, 8, 1, "P"),
"RGB": (5, 8, 3, "RGB;L"),
}
def _save(im, fp, filename):
try:
version, bits, planes, rawmode = SAVE[im.mode]
except KeyError as e:
raise ValueError(f"Cannot save {im.mode} images as PCX") from e
# bytes per plane
stride = (im.size[0] * bits + 7) // 8
# stride should be even
stride += stride % 2
# Stride needs to be kept in sync with the PcxEncode.c version.
# Ideally it should be passed in in the state, but the bytes value
# gets overwritten.
logger.debug(
"PcxImagePlugin._save: xwidth: %d, bits: %d, stride: %d",
im.size[0],
bits,
stride,
)
# under windows, we could determine the current screen size with
# "Image.core.display_mode()[1]", but I think that's overkill...
screen = im.size
dpi = 100, 100
# PCX header
fp.write(
o8(10)
+ o8(version)
+ o8(1)
+ o8(bits)
+ o16(0)
+ o16(0)
+ o16(im.size[0] - 1)
+ o16(im.size[1] - 1)
+ o16(dpi[0])
+ o16(dpi[1])
+ b"\0" * 24
+ b"\xFF" * 24
+ b"\0"
+ o8(planes)
+ o16(stride)
+ o16(1)
+ o16(screen[0])
+ o16(screen[1])
+ b"\0" * 54
)
assert fp.tell() == 128
ImageFile._save(im, fp, [("pcx", (0, 0) + im.size, 0, (rawmode, bits * planes))])
if im.mode == "P":
# colour palette
fp.write(o8(12))
palette = im.im.getpalette("RGB", "RGB")
palette += b"\x00" * (768 - len(palette))
fp.write(palette) # 768 bytes
elif im.mode == "L":
# greyscale palette
fp.write(o8(12))
for i in range(256):
fp.write(o8(i) * 3)
# --------------------------------------------------------------------
# registry
Image.register_open(PcxImageFile.format, PcxImageFile, _accept)
Image.register_save(PcxImageFile.format, _save)
Image.register_extension(PcxImageFile.format, ".pcx")
Image.register_mime(PcxImageFile.format, "image/x-pcx")
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