Pillow/src/PIL/EpsImagePlugin.py
Jon Dufresne 63729766c4 Remove unnecessary coerce to float
In Python 3, the division operator is floating point division. No longer
need to coerce integers to floating point numbers before division.
2020-01-26 06:33:18 -08:00

418 lines
12 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)
# 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 io
import os
import re
import subprocess
import sys
import tempfile
from . import Image, ImageFile
from ._binary import i32le as i32
#
# --------------------------------------------------------------------
split = re.compile(r"^%%([^:]*):[ \t]*(.*)[ \t]*$")
field = re.compile(r"^%[%!\w]([^:]*)[ \t]*$")
gs_windows_binary = None
if sys.platform.startswith("win"):
import shutil
for binary in ("gswin32c", "gswin64c", "gs"):
if shutil.which(binary) is not None:
gs_windows_binary = binary
break
else:
gs_windows_binary = False
def has_ghostscript():
if gs_windows_binary:
return True
if not sys.platform.startswith("win"):
try:
subprocess.check_call(["gs", "--version"], stdout=subprocess.DEVNULL)
return True
except OSError:
# No Ghostscript
pass
return 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)
# resolution is dependent on bbox and size
res = (
72.0 * size[0] / (bbox[2] - bbox[0]),
72.0 * size[1] / (bbox[3] - bbox[1]),
)
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, io.SEEK_END)
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)
"-dBATCH", # exit after processing
"-dNOPAUSE", # don't pause between pages
"-dSAFER", # safe mode
"-sDEVICE=ppmraw", # ppm driver
"-sOutputFile=%s" % outfile, # output file
# adjust for image origin
"-c",
"%d %d translate" % (-bbox[0], -bbox[1]),
"-f",
infile, # input file
# showpage (see https://bugs.ghostscript.com/show_bug.cgi?id=698272)
"-c",
"showpage",
]
if gs_windows_binary is not None:
if not gs_windows_binary:
raise OSError("Unable to locate Ghostscript on paths")
command[0] = gs_windows_binary
# push data through Ghostscript
try:
startupinfo = None
if sys.platform.startswith("win"):
startupinfo = subprocess.STARTUPINFO()
startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
subprocess.check_call(command, startupinfo=startupinfo)
im = Image.open(outfile)
im.load()
finally:
try:
os.unlink(outfile)
if infile_temp:
os.unlink(infile_temp)
except OSError:
pass
return im.im.copy()
class PSFile:
"""
Wrapper for bytesio object that treats either CR or LF as end of line.
"""
def __init__(self, fp):
self.fp = fp
self.char = None
def seek(self, offset, whence=io.SEEK_SET):
self.char = None
self.fp.seek(offset, whence)
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.
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", 4: "CMYK"}
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.
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_raw = fp.readline()
s = s_raw.strip("\r\n")
while s_raw:
if s:
if len(s) > 255:
raise SyntaxError("not an EPS file")
try:
m = split.match(s)
except re.error:
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 Exception:
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 OSError("bad EPS header")
s_raw = fp.readline()
s = s_raw.strip("\r\n")
if s and 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 OSError("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, io.SEEK_END)
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:
# https://web.archive.org/web/20160528181353/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)
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 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")
base_fp = fp
wrapped_fp = False
if fp != sys.stdout:
fp = io.TextIOWrapper(fp, encoding="latin-1")
wrapped_fp = True
try:
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()
finally:
if wrapped_fp:
fp.detach()
#
# --------------------------------------------------------------------
Image.register_open(EpsImageFile.format, EpsImageFile, _accept)
Image.register_save(EpsImageFile.format, _save)
Image.register_extensions(EpsImageFile.format, [".ps", ".eps"])
Image.register_mime(EpsImageFile.format, "application/postscript")