#
# The Python Imaging Library.
# $Id$
#
# EPS file handling
#
# History:
# 1995-09-01 fl Created (0.1)
# 1996-05-18 fl Don't choke on "atend" fields, Ghostscript interface (0.2)
# 1996-08-22 fl Don't choke on floating point BoundingBox values
# 1996-08-23 fl Handle files from Macintosh (0.3)
# 2001-02-17 fl Use 're' instead of 'regex' (Python 2.1) (0.4)
# 2003-09-07 fl Check gs.close status (from Federico Di Gregorio) (0.5)
# 2014-05-07 e Handling of EPS with binary preview and fixed resolution
# resizing
#
# 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 re
import io
import sys
from PIL import Image, ImageFile, _binary
__version__ = "0.5"
#
# --------------------------------------------------------------------
i32 = _binary.i32le
o32 = _binary.o32le
split = re.compile(r"^%%([^:]*):[ \t]*(.*)[ \t]*$")
field = re.compile(r"^%[%!\w]([^:]*)[ \t]*$")
gs_windows_binary = None
if sys.platform.startswith('win'):
import shutil
if hasattr(shutil, 'which'):
which = shutil.which
else:
# Python < 3.3
import distutils.spawn
which = distutils.spawn.find_executable
for binary in ('gswin32c', 'gswin64c', 'gs'):
if which(binary) is not None:
gs_windows_binary = binary
break
else:
gs_windows_binary = False
[文档]def has_ghostscript():
if gs_windows_binary:
return True
if not sys.platform.startswith('win'):
import subprocess
try:
gs = subprocess.Popen(['gs', '--version'], stdout=subprocess.PIPE)
gs.stdout.read()
return True
except OSError:
# no ghostscript
pass
return False
[文档]def Ghostscript(tile, size, fp, scale=1):
"""Render an image using Ghostscript"""
# Unpack decoder tile
decoder, tile, offset, data = tile[0]
length, bbox = data
# Hack to support hi-res rendering
scale = int(scale) or 1
# orig_size = size
# orig_bbox = bbox
size = (size[0] * scale, size[1] * scale)
# resolution is dependent on bbox and size
res = (float((72.0 * size[0]) / (bbox[2]-bbox[0])),
float((72.0 * size[1]) / (bbox[3]-bbox[1])))
# print("Ghostscript", scale, size, orig_size, bbox, orig_bbox, res)
import os
import subprocess
import tempfile
out_fd, outfile = tempfile.mkstemp()
os.close(out_fd)
infile_temp = None
if hasattr(fp, 'name') and os.path.exists(fp.name):
infile = fp.name
else:
in_fd, infile_temp = tempfile.mkstemp()
os.close(in_fd)
infile = infile_temp
# ignore length and offset!
# ghostscript can read it
# copy whole file to read in ghostscript
with open(infile_temp, 'wb') as f:
# fetch length of fp
fp.seek(0, 2)
fsize = fp.tell()
# ensure start position
# go back
fp.seek(0)
lengthfile = fsize
while lengthfile > 0:
s = fp.read(min(lengthfile, 100*1024))
if not s:
break
lengthfile -= len(s)
f.write(s)
# Build ghostscript command
command = ["gs",
"-q", # quiet mode
"-g%dx%d" % size, # set output geometry (pixels)
"-r%fx%f" % res, # set input DPI (dots per inch)
"-dNOPAUSE", # don't pause between pages,
"-dSAFER", # safe mode
"-sDEVICE=ppmraw", # ppm driver
"-sOutputFile=%s" % outfile, # output file
"-c", "%d %d translate" % (-bbox[0], -bbox[1]),
# adjust for image origin
"-f", infile, # input file
]
if gs_windows_binary is not None:
if not gs_windows_binary:
raise WindowsError('Unable to locate Ghostscript on paths')
command[0] = gs_windows_binary
# push data through ghostscript
try:
gs = subprocess.Popen(command, stdin=subprocess.PIPE,
stdout=subprocess.PIPE)
gs.stdin.close()
status = gs.wait()
if status:
raise IOError("gs failed (status %d)" % status)
im = Image.core.open_ppm(outfile)
finally:
try:
os.unlink(outfile)
if infile_temp:
os.unlink(infile_temp)
except OSError:
pass
return im
[文档]class PSFile(object):
"""
Wrapper for bytesio object that treats either CR or LF as end of line.
"""
def __init__(self, fp):
self.fp = fp
self.char = None
[文档] def seek(self, offset, whence=0):
self.char = None
self.fp.seek(offset, whence)
[文档] def readline(self):
s = self.char or b""
self.char = None
c = self.fp.read(1)
while c not in b"\r\n":
s = s + c
c = self.fp.read(1)
self.char = self.fp.read(1)
# line endings can be 1 or 2 of \r \n, in either order
if self.char in b"\r\n":
self.char = None
return s.decode('latin-1')
def _accept(prefix):
return prefix[:4] == b"%!PS" or \
(len(prefix) >= 4 and i32(prefix) == 0xC6D3D0C5)
##
# Image plugin for Encapsulated Postscript. This plugin supports only
# a few variants of this format.
[文档]class EpsImageFile(ImageFile.ImageFile):
"""EPS File Parser for the Python Imaging Library"""
format = "EPS"
format_description = "Encapsulated Postscript"
mode_map = {1: "L", 2: "LAB", 3: "RGB"}
def _open(self):
(length, offset) = self._find_offset(self.fp)
# Rewrap the open file pointer in something that will
# convert line endings and decode to latin-1.
try:
if bytes is str:
# Python2, no encoding conversion necessary
fp = open(self.fp.name, "Ur")
else:
# Python3, can use bare open command.
fp = open(self.fp.name, "Ur", encoding='latin-1')
except:
# Expect this for bytesio/stringio
fp = PSFile(self.fp)
# go to offset - start of "%!PS"
fp.seek(offset)
box = None
self.mode = "RGB"
self.size = 1, 1 # FIXME: huh?
#
# Load EPS header
s = fp.readline().strip('\r\n')
while s:
if len(s) > 255:
raise SyntaxError("not an EPS file")
try:
m = split.match(s)
except re.error as v:
raise SyntaxError("not an EPS file")
if m:
k, v = m.group(1, 2)
self.info[k] = v
if k == "BoundingBox":
try:
# Note: The DSC spec says that BoundingBox
# fields should be integers, but some drivers
# put floating point values there anyway.
box = [int(float(i)) for i in v.split()]
self.size = box[2] - box[0], box[3] - box[1]
self.tile = [("eps", (0, 0) + self.size, offset,
(length, box))]
except:
pass
else:
m = field.match(s)
if m:
k = m.group(1)
if k == "EndComments":
break
if k[:8] == "PS-Adobe":
self.info[k[:8]] = k[9:]
else:
self.info[k] = ""
elif s[0] == '%':
# handle non-DSC Postscript comments that some
# tools mistakenly put in the Comments section
pass
else:
raise IOError("bad EPS header")
s = fp.readline().strip('\r\n')
if s[:1] != "%":
break
#
# Scan for an "ImageData" descriptor
while s[:1] == "%":
if len(s) > 255:
raise SyntaxError("not an EPS file")
if s[:11] == "%ImageData:":
# Encoded bitmapped image.
x, y, bi, mo = s[11:].split(None, 7)[:4]
if int(bi) != 8:
break
try:
self.mode = self.mode_map[int(mo)]
except ValueError:
break
self.size = int(x), int(y)
return
s = fp.readline().strip('\r\n')
if not s:
break
if not box:
raise IOError("cannot determine EPS bounding box")
def _find_offset(self, fp):
s = fp.read(160)
if s[:4] == b"%!PS":
# for HEAD without binary preview
fp.seek(0, 2)
length = fp.tell()
offset = 0
elif i32(s[0:4]) == 0xC6D3D0C5:
# FIX for: Some EPS file not handled correctly / issue #302
# EPS can contain binary data
# or start directly with latin coding
# more info see:
# http://partners.adobe.com/public/developer/en/ps/5002.EPSF_Spec.pdf
offset = i32(s[4:8])
length = i32(s[8:12])
else:
raise SyntaxError("not an EPS file")
return (length, offset)
[文档] def load(self, scale=1):
# Load EPS via Ghostscript
if not self.tile:
return
self.im = Ghostscript(self.tile, self.size, self.fp, scale)
self.mode = self.im.mode
self.size = self.im.size
self.tile = []
[文档] def load_seek(self, *args, **kwargs):
# we can't incrementally load, so force ImageFile.parser to
# use our custom load method by defining this method.
pass
#
# --------------------------------------------------------------------
def _save(im, fp, filename, eps=1):
"""EPS Writer for the Python Imaging Library."""
#
# make sure image data is available
im.load()
#
# determine postscript image mode
if im.mode == "L":
operator = (8, 1, "image")
elif im.mode == "RGB":
operator = (8, 3, "false 3 colorimage")
elif im.mode == "CMYK":
operator = (8, 4, "false 4 colorimage")
else:
raise ValueError("image mode is not supported")
class NoCloseStream(object):
def __init__(self, fp):
self.fp = fp
def __getattr__(self, name):
return getattr(self.fp, name)
def close(self):
pass
base_fp = fp
if fp != sys.stdout:
fp = NoCloseStream(fp)
if sys.version_info[0] > 2:
fp = io.TextIOWrapper(fp, encoding='latin-1')
if eps:
#
# write EPS header
fp.write("%!PS-Adobe-3.0 EPSF-3.0\n")
fp.write("%%Creator: PIL 0.1 EpsEncode\n")
# fp.write("%%CreationDate: %s"...)
fp.write("%%%%BoundingBox: 0 0 %d %d\n" % im.size)
fp.write("%%Pages: 1\n")
fp.write("%%EndComments\n")
fp.write("%%Page: 1 1\n")
fp.write("%%ImageData: %d %d " % im.size)
fp.write("%d %d 0 1 1 \"%s\"\n" % operator)
#
# image header
fp.write("gsave\n")
fp.write("10 dict begin\n")
fp.write("/buf %d string def\n" % (im.size[0] * operator[1]))
fp.write("%d %d scale\n" % im.size)
fp.write("%d %d 8\n" % im.size) # <= bits
fp.write("[%d 0 0 -%d 0 %d]\n" % (im.size[0], im.size[1], im.size[1]))
fp.write("{ currentfile buf readhexstring pop } bind\n")
fp.write(operator[2] + "\n")
if hasattr(fp, "flush"):
fp.flush()
ImageFile._save(im, base_fp, [("eps", (0, 0)+im.size, 0, None)])
fp.write("\n%%%%EndBinary\n")
fp.write("grestore end\n")
if hasattr(fp, "flush"):
fp.flush()
#
# --------------------------------------------------------------------
Image.register_open(EpsImageFile.format, EpsImageFile, _accept)
Image.register_save(EpsImageFile.format, _save)
Image.register_extension(EpsImageFile.format, ".ps")
Image.register_extension(EpsImageFile.format, ".eps")
Image.register_mime(EpsImageFile.format, "application/postscript")