Source code for PIL.PcxImagePlugin

#
# 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.

[docs]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")