Pillow/PIL/EpsImagePlugin.py
Esteban Santana Santana 7989378bfd Added a way to specify the render size for EPS files.
There is now a scale parameter that you can pass in to the EpsImageFile.load() function. This parameter is used to specify at what scale Ghostscript renders the EPS internally. Scale needs to be an integer, and all of the internal structures (image size and bounding box) are scaled based on that parameter.
2013-11-17 01:26:44 -06:00

399 lines
11 KiB
Python

#
# 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)
#
# 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.
#
__version__ = "0.5"
import re
import io
from PIL import Image, ImageFile, _binary
#
# --------------------------------------------------------------------
i32 = _binary.i32le
o32 = _binary.o32le
split = re.compile(r"^%%([^:]*):[ \t]*(.*)[ \t]*$")
field = re.compile(r"^%[%!\w]([^:]*)[ \t]*$")
gs_windows_binary = None
import sys
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
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)
bbox = [bbox[0], bbox[1], bbox[2] * scale, bbox[3] * scale]
#print("Ghostscript", scale, size, orig_size, bbox, orig_bbox)
import tempfile, os
file = tempfile.mktemp()
# Build ghostscript command
command = ["gs",
"-q", # quite mode
"-g%dx%d" % size, # set output geometry (pixels)
"-r%d" % (72*scale), # set input DPI (dots per inch)
"-dNOPAUSE -dSAFER", # don't pause between pages, safe mode
"-sDEVICE=ppmraw", # ppm driver
"-sOutputFile=%s" % file,# output file
"- >/dev/null 2>/dev/null"]
if gs_windows_binary is not None:
if gs_windows_binary is False:
raise WindowsError('Unable to locate Ghostscript on paths')
command[0] = gs_windows_binary
command[-1] = '- >nul 2>nul'
command = " ".join(command)
# push data through ghostscript
try:
gs = os.popen(command, "w")
# adjust for image origin
if bbox[0] != 0 or bbox[1] != 0:
gs.write("%d %d translate\n" % (-bbox[0], -bbox[1]))
fp.seek(offset)
while length > 0:
s = fp.read(8192)
if not s:
break
length = length - len(s)
gs.write(s)
status = gs.close()
if status:
raise IOError("gs failed (status %d)" % status)
im = Image.core.open_ppm(file)
finally:
try: os.unlink(file)
except: pass
return im
class PSFile:
"""Wrapper that treats either CR or LF as end of line."""
def __init__(self, fp):
self.fp = fp
self.char = None
def __getattr__(self, id):
v = getattr(self.fp, id)
setattr(self, id, v)
return v
def seek(self, offset, whence=0):
self.char = None
self.fp.seek(offset, whence)
def read(self, count):
return self.fp.read(count).decode('latin-1')
def tell(self):
pos = self.fp.tell()
if self.char:
pos = pos - 1
return pos
def readline(self):
s = b""
if self.char:
c = self.char
self.char = None
else:
c = self.fp.read(1)
while c not in b"\r\n":
s = s + c
c = self.fp.read(1)
if c == b"\r":
self.char = self.fp.read(1)
if self.char == b"\n":
self.char = None
return s.decode('latin-1') + "\n"
def _accept(prefix):
return prefix[:4] == b"%!PS" or i32(prefix) == 0xC6D3D0C5
##
# Image plugin for Encapsulated Postscript. This plugin supports only
# a few variants of this format.
class EpsImageFile(ImageFile.ImageFile):
"""EPS File Parser for the Python Imaging Library"""
format = "EPS"
format_description = "Encapsulated Postscript"
def _open(self):
# FIXME: should check the first 512 bytes to see if this
# really is necessary (platform-dependent, though...)
fp = PSFile(self.fp)
# HEAD
s = fp.read(512)
if s[:4] == "%!PS":
offset = 0
fp.seek(0, 2)
length = fp.tell()
elif i32(s) == 0xC6D3D0C5:
offset = i32(s[4:])
length = i32(s[8:])
fp.seek(offset)
else:
raise SyntaxError("not an EPS file")
fp.seek(offset)
box = None
self.mode = "RGB"
self.size = 1, 1 # FIXME: huh?
#
# Load EPS header
s = fp.readline()
while s:
if len(s) > 255:
raise SyntaxError("not an EPS file")
if s[-2:] == '\r\n':
s = s[:-2]
elif s[-1:] == '\n':
s = s[:-1]
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(s)) for s 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[0:1] == '%':
# handle non-DSC Postscript comments that some
# tools mistakenly put in the Comments section
pass
else:
raise IOError("bad EPS header")
s = fp.readline()
if s[:1] != "%":
break
#
# Scan for an "ImageData" descriptor
while s[0] == "%":
if len(s) > 255:
raise SyntaxError("not an EPS file")
if s[-2:] == '\r\n':
s = s[:-2]
elif s[-1:] == '\n':
s = s[:-1]
if s[:11] == "%ImageData:":
[x, y, bi, mo, z3, z4, en, id] =\
s[11:].split(None, 7)
x = int(x); y = int(y)
bi = int(bi)
mo = int(mo)
en = int(en)
if en == 1:
decoder = "eps_binary"
elif en == 2:
decoder = "eps_hex"
else:
break
if bi != 8:
break
if mo == 1:
self.mode = "L"
elif mo == 2:
self.mode = "LAB"
elif mo == 3:
self.mode = "RGB"
else:
break
if id[:1] == id[-1:] == '"':
id = id[1:-1]
# Scan forward to the actual image data
while True:
s = fp.readline()
if not s:
break
if s[:len(id)] == id:
self.size = x, y
self.tile2 = [(decoder,
(0, 0, x, y),
fp.tell(),
0)]
return
s = fp.readline()
if not s:
break
if not box:
raise IOError("cannot determine EPS bounding box")
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 = []
#
# --------------------------------------------------------------------
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:
def __init__(self, fp):
self.fp = fp
def __getattr__(self, name):
return getattr(self.fp, name)
def close(self):
pass
base_fp = fp
fp = io.TextIOWrapper(NoCloseStream(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")
fp.flush()
ImageFile._save(im, base_fp, [("eps", (0,0)+im.size, 0, None)])
fp.write("\n%%%%EndBinary\n")
fp.write("grestore end\n")
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")