165 lines
4.3 KiB
Python
165 lines
4.3 KiB
Python
#
|
|
# 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.
|
|
#
|
|
|
|
|
|
from . import Image, ImageFile
|
|
|
|
#
|
|
# --------------------------------------------------------------------
|
|
|
|
b_whitespace = b"\x20\x09\x0a\x0b\x0c\x0d"
|
|
|
|
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.
|
|
|
|
|
|
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
|
|
if c > b"\x79":
|
|
raise ValueError("Expected ASCII value, found binary")
|
|
s = s + c
|
|
if len(s) > 9:
|
|
raise ValueError("Expected int, got > 9 digits")
|
|
return s
|
|
|
|
def _open(self):
|
|
|
|
# check magic
|
|
s = self.fp.read(1)
|
|
if s != b"P":
|
|
raise SyntaxError("not a PPM file")
|
|
magic_number = self._token(s)
|
|
mode = MODES[magic_number]
|
|
|
|
self.custom_mimetype = {
|
|
b"P4": "image/x-portable-bitmap",
|
|
b"P5": "image/x-portable-graymap",
|
|
b"P6": "image/x-portable-pixmap",
|
|
}.get(magic_number)
|
|
|
|
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"":
|
|
raise ValueError("File does not extend beyond magic number")
|
|
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
|
|
elif ix == 2:
|
|
# maxgrey
|
|
if s > 255:
|
|
if not mode == "L":
|
|
raise ValueError("Too many colors for band: %s" % s)
|
|
if s < 2 ** 16:
|
|
self.mode = "I"
|
|
rawmode = "I;16B"
|
|
else:
|
|
self.mode = "I"
|
|
rawmode = "I;32B"
|
|
|
|
self._size = xsize, ysize
|
|
self.tile = [("raw", (0, 0, xsize, ysize), self.fp.tell(), (rawmode, 0, 1))]
|
|
|
|
|
|
#
|
|
# --------------------------------------------------------------------
|
|
|
|
|
|
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 == "I":
|
|
if im.getextrema()[1] < 2 ** 16:
|
|
rawmode, head = "I;16B", b"P5"
|
|
else:
|
|
rawmode, head = "I;32B", b"P5"
|
|
elif im.mode == "RGB":
|
|
rawmode, head = "RGB", b"P6"
|
|
elif im.mode == "RGBA":
|
|
rawmode, head = "RGB", b"P6"
|
|
else:
|
|
raise OSError("cannot write mode %s as PPM" % im.mode)
|
|
fp.write(head + ("\n%d %d\n" % im.size).encode("ascii"))
|
|
if head == b"P6":
|
|
fp.write(b"255\n")
|
|
if head == b"P5":
|
|
if rawmode == "L":
|
|
fp.write(b"255\n")
|
|
elif rawmode == "I;16B":
|
|
fp.write(b"65535\n")
|
|
elif rawmode == "I;32B":
|
|
fp.write(b"2147483648\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(PpmImageFile.format, PpmImageFile, _accept)
|
|
Image.register_save(PpmImageFile.format, _save)
|
|
|
|
Image.register_extensions(PpmImageFile.format, [".pbm", ".pgm", ".ppm", ".pnm"])
|
|
|
|
Image.register_mime(PpmImageFile.format, "image/x-portable-anymap")
|