Hi,
I have changed the PPM reading of PIL (the file PpmImagePlugin.py) so
that it would read and write comments in the PPM header (starting with
"#" in the beginning of the file).
Attached is my modified version of this file (I work with the latest
1.1.6 version) which is capable of loading and saving PPM comments.
I think it would be beneficial to apply this change to future versions of PIL.
Thanks,
Ran
#
# The Python Imaging Library.
# $Id: PpmImagePlugin.py 2134 2004-10-06 08:55:20Z fredrik $
#
# 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
import Image, ImageFile
#
# --------------------------------------------------------------------
MODES = {
# standard
"P4": "1",
"P5": "L",
"P6": "RGB",
# extensions
"P0CMYK": "CMYK",
# PIL extensions (for test purposes only)
"PyP": "P",
"PyRGBA": "RGBA",
"PyCMYK": "CMYK"
}
def _accept(prefix):
return prefix[0] == "P" and prefix[1] in "0456y"
##
# Image plugin for PBM, PGM, and PPM images.
class PpmImageFile(ImageFile.ImageFile):
format = "PPM"
format_description = "Pbmplus image"
def _token(self, s = ""):
while 1: # read until next whitespace
c = self.fp.read(1)
if not c or c in string.whitespace:
break
s = s + c
return s
def _open(self):
# check magic
s = self.fp.read(1)
if s != "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
self.info = {}
self.info["comments"] = []
for ix in range(3):
while 1:
while 1:
s = self.fp.read(1)
if s not in string.whitespace:
break
if s != "#":
break
s = self.fp.readline()
self.info["comments"].append(s[:-1])
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", "P4"
elif im.mode == "L":
rawmode, head = "L", "P5"
elif im.mode == "RGB":
rawmode, head = "RGB", "P6"
elif im.mode == "RGBA":
rawmode, head = "RGB", "P6"
else:
raise IOError, "cannot write mode %s as PPM" % im.mode
if ('info' in dir(im)):
if (im.info.has_key('comments')):
for comment in im.info['comments']:
head += "\n#" + comment
fp.write(head + "\n%d %d\n" % im.size)
if head != "P4":
fp.write("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")
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