Source code for PIL.PpmImagePlugin

#
# The Python Imaging Library.
# $Id$
#
# PPM support for PIL
#
# History:
#       96-03-24 fl     Created
#       98-03-06 fl     Write RGBA images (as RGB, that is)
#
# Copyright (c) Secret Labs AB 1997-98.
# Copyright (c) Fredrik Lundh 1996.
#
# See the README file for information on usage and redistribution.
#


__version__ = "0.2"

import string

from PIL import Image, ImageFile

#
# --------------------------------------------------------------------

b_whitespace = string.whitespace.encode()

MODES = {
    # standard
    b"P4": "1",
    b"P5": "L",
    b"P6": "RGB",
    # extensions
    b"P0CMYK": "CMYK",
    # PIL extensions (for test purposes only)
    b"PyP": "P",
    b"PyRGBA": "RGBA",
    b"PyCMYK": "CMYK"
}

def _accept(prefix):
    return prefix[0:1] == b"P" and prefix[1] in b"0456y"

##
# Image plugin for PBM, PGM, and PPM images.

[docs]class PpmImageFile(ImageFile.ImageFile): format = "PPM" format_description = "Pbmplus image" def _token(self, s = b""): while True: # read until next whitespace c = self.fp.read(1) if not c or c in b_whitespace: break s = s + c return s def _open(self): # check magic s = self.fp.read(1) if s != b"P": raise SyntaxError("not a PPM file") mode = MODES[self._token(s)] if mode == "1": self.mode = "1" rawmode = "1;I" else: self.mode = rawmode = mode for ix in range(3): while True: while True: s = self.fp.read(1) if s not in b_whitespace: break if s != b"#": break s = self.fp.readline() s = int(self._token(s)) if ix == 0: xsize = s elif ix == 1: ysize = s if mode == "1": break self.size = xsize, ysize self.tile = [("raw", (0, 0, xsize, ysize), self.fp.tell(), (rawmode, 0, 1))] # ALTERNATIVE: load via builtin debug function # self.im = Image.core.open_ppm(self.filename) # self.mode = self.im.mode # self.size = self.im.size # # --------------------------------------------------------------------
def _save(im, fp, filename): if im.mode == "1": rawmode, head = "1;I", b"P4" elif im.mode == "L": rawmode, head = "L", b"P5" elif im.mode == "RGB": rawmode, head = "RGB", b"P6" elif im.mode == "RGBA": rawmode, head = "RGB", b"P6" else: raise IOError("cannot write mode %s as PPM" % im.mode) fp.write(head + ("\n%d %d\n" % im.size).encode('ascii')) if head != b"P4": fp.write(b"255\n") ImageFile._save(im, fp, [("raw", (0,0)+im.size, 0, (rawmode, 0, 1))]) # ALTERNATIVE: save via builtin debug function # im._dump(filename) # # -------------------------------------------------------------------- Image.register_open("PPM", PpmImageFile, _accept) Image.register_save("PPM", _save) Image.register_extension("PPM", ".pbm") Image.register_extension("PPM", ".pgm") Image.register_extension("PPM", ".ppm")