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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 logging
- from . import Image, ImageFile, ImagePalette
- from ._binary import i8, i16le as i16, o8, o16le as o16
-
- logger = logging.getLogger(__name__)
-
- __version__ = "0.6"
-
-
- def _accept(prefix):
- return i8(prefix[0]) == 10 and i8(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 = i8(s[1])
- bits = i8(s[3])
- planes = i8(s[65])
- stride = i16(s, 66)
- logger.debug("PCX version %s, bits %s, planes %s, stride %s",
- version, bits, planes, 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, 2)
- s = self.fp.read(769)
- if len(s) == 769 and i8(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 IOError("unknown PCX mode")
-
- self.mode = mode
- self._size = bbox[2]-bbox[0], bbox[3]-bbox[1]
-
- 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:
- raise ValueError("Cannot save %s images as PCX" % im.mode)
-
- # 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))
- fp.write(im.im.getpalette("RGB", "RGB")) # 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")
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