forked from varia/varia.website
420 lines
12 KiB
Python
420 lines
12 KiB
Python
#
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# The Python Imaging Library.
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# $Id$
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#
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# EPS file handling
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#
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# History:
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# 1995-09-01 fl Created (0.1)
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# 1996-05-18 fl Don't choke on "atend" fields, Ghostscript interface (0.2)
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# 1996-08-22 fl Don't choke on floating point BoundingBox values
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# 1996-08-23 fl Handle files from Macintosh (0.3)
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# 2001-02-17 fl Use 're' instead of 'regex' (Python 2.1) (0.4)
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# 2003-09-07 fl Check gs.close status (from Federico Di Gregorio) (0.5)
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# 2014-05-07 e Handling of EPS with binary preview and fixed resolution
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# resizing
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#
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# Copyright (c) 1997-2003 by Secret Labs AB.
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# Copyright (c) 1995-2003 by Fredrik Lundh
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#
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# See the README file for information on usage and redistribution.
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#
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import io
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import os
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import re
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import subprocess
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import sys
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import tempfile
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from . import Image, ImageFile
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from ._binary import i32le as i32
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#
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# --------------------------------------------------------------------
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split = re.compile(r"^%%([^:]*):[ \t]*(.*)[ \t]*$")
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field = re.compile(r"^%[%!\w]([^:]*)[ \t]*$")
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gs_windows_binary = None
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if sys.platform.startswith("win"):
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import shutil
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for binary in ("gswin32c", "gswin64c", "gs"):
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if shutil.which(binary) is not None:
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gs_windows_binary = binary
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break
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else:
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gs_windows_binary = False
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def has_ghostscript():
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if gs_windows_binary:
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return True
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if not sys.platform.startswith("win"):
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try:
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subprocess.check_call(["gs", "--version"], stdout=subprocess.DEVNULL)
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return True
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except OSError:
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# No Ghostscript
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pass
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return False
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def Ghostscript(tile, size, fp, scale=1):
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"""Render an image using Ghostscript"""
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# Unpack decoder tile
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decoder, tile, offset, data = tile[0]
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length, bbox = data
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# Hack to support hi-res rendering
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scale = int(scale) or 1
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# orig_size = size
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# orig_bbox = bbox
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size = (size[0] * scale, size[1] * scale)
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# resolution is dependent on bbox and size
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res = (
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72.0 * size[0] / (bbox[2] - bbox[0]),
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72.0 * size[1] / (bbox[3] - bbox[1]),
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)
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out_fd, outfile = tempfile.mkstemp()
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os.close(out_fd)
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infile_temp = None
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if hasattr(fp, "name") and os.path.exists(fp.name):
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infile = fp.name
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else:
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in_fd, infile_temp = tempfile.mkstemp()
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os.close(in_fd)
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infile = infile_temp
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# Ignore length and offset!
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# Ghostscript can read it
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# Copy whole file to read in Ghostscript
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with open(infile_temp, "wb") as f:
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# fetch length of fp
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fp.seek(0, io.SEEK_END)
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fsize = fp.tell()
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# ensure start position
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# go back
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fp.seek(0)
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lengthfile = fsize
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while lengthfile > 0:
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s = fp.read(min(lengthfile, 100 * 1024))
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if not s:
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break
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lengthfile -= len(s)
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f.write(s)
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# Build Ghostscript command
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command = [
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"gs",
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"-q", # quiet mode
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"-g%dx%d" % size, # set output geometry (pixels)
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"-r%fx%f" % res, # set input DPI (dots per inch)
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"-dBATCH", # exit after processing
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"-dNOPAUSE", # don't pause between pages
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"-dSAFER", # safe mode
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"-sDEVICE=ppmraw", # ppm driver
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f"-sOutputFile={outfile}", # output file
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# adjust for image origin
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"-c",
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f"{-bbox[0]} {-bbox[1]} translate",
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"-f",
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infile, # input file
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# showpage (see https://bugs.ghostscript.com/show_bug.cgi?id=698272)
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"-c",
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"showpage",
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]
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if gs_windows_binary is not None:
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if not gs_windows_binary:
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raise OSError("Unable to locate Ghostscript on paths")
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command[0] = gs_windows_binary
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# push data through Ghostscript
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try:
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startupinfo = None
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if sys.platform.startswith("win"):
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startupinfo = subprocess.STARTUPINFO()
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startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
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subprocess.check_call(command, startupinfo=startupinfo)
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out_im = Image.open(outfile)
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out_im.load()
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finally:
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try:
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os.unlink(outfile)
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if infile_temp:
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os.unlink(infile_temp)
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except OSError:
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pass
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im = out_im.im.copy()
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out_im.close()
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return im
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class PSFile:
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"""
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Wrapper for bytesio object that treats either CR or LF as end of line.
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"""
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def __init__(self, fp):
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self.fp = fp
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self.char = None
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def seek(self, offset, whence=io.SEEK_SET):
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self.char = None
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self.fp.seek(offset, whence)
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def readline(self):
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s = self.char or b""
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self.char = None
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c = self.fp.read(1)
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while c not in b"\r\n":
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s = s + c
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c = self.fp.read(1)
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self.char = self.fp.read(1)
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# line endings can be 1 or 2 of \r \n, in either order
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if self.char in b"\r\n":
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self.char = None
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return s.decode("latin-1")
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def _accept(prefix):
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return prefix[:4] == b"%!PS" or (len(prefix) >= 4 and i32(prefix) == 0xC6D3D0C5)
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##
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# Image plugin for Encapsulated PostScript. This plugin supports only
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# a few variants of this format.
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class EpsImageFile(ImageFile.ImageFile):
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"""EPS File Parser for the Python Imaging Library"""
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format = "EPS"
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format_description = "Encapsulated Postscript"
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mode_map = {1: "L", 2: "LAB", 3: "RGB", 4: "CMYK"}
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def _open(self):
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(length, offset) = self._find_offset(self.fp)
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# Rewrap the open file pointer in something that will
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# convert line endings and decode to latin-1.
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fp = PSFile(self.fp)
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# go to offset - start of "%!PS"
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fp.seek(offset)
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box = None
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self.mode = "RGB"
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self._size = 1, 1 # FIXME: huh?
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#
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# Load EPS header
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s_raw = fp.readline()
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s = s_raw.strip("\r\n")
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while s_raw:
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if s:
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if len(s) > 255:
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raise SyntaxError("not an EPS file")
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try:
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m = split.match(s)
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except re.error as e:
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raise SyntaxError("not an EPS file") from e
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if m:
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k, v = m.group(1, 2)
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self.info[k] = v
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if k == "BoundingBox":
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try:
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# Note: The DSC spec says that BoundingBox
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# fields should be integers, but some drivers
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# put floating point values there anyway.
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box = [int(float(i)) for i in v.split()]
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self._size = box[2] - box[0], box[3] - box[1]
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self.tile = [
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("eps", (0, 0) + self.size, offset, (length, box))
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]
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except Exception:
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pass
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else:
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m = field.match(s)
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if m:
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k = m.group(1)
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if k == "EndComments":
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break
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if k[:8] == "PS-Adobe":
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self.info[k[:8]] = k[9:]
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else:
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self.info[k] = ""
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elif s[0] == "%":
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# handle non-DSC PostScript comments that some
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# tools mistakenly put in the Comments section
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pass
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else:
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raise OSError("bad EPS header")
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s_raw = fp.readline()
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s = s_raw.strip("\r\n")
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if s and s[:1] != "%":
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break
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#
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# Scan for an "ImageData" descriptor
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while s[:1] == "%":
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if len(s) > 255:
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raise SyntaxError("not an EPS file")
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if s[:11] == "%ImageData:":
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# Encoded bitmapped image.
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x, y, bi, mo = s[11:].split(None, 7)[:4]
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if int(bi) != 8:
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break
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try:
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self.mode = self.mode_map[int(mo)]
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except ValueError:
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break
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self._size = int(x), int(y)
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return
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s = fp.readline().strip("\r\n")
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if not s:
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break
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if not box:
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raise OSError("cannot determine EPS bounding box")
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def _find_offset(self, fp):
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s = fp.read(160)
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if s[:4] == b"%!PS":
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# for HEAD without binary preview
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fp.seek(0, io.SEEK_END)
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length = fp.tell()
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offset = 0
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elif i32(s, 0) == 0xC6D3D0C5:
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# FIX for: Some EPS file not handled correctly / issue #302
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# EPS can contain binary data
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# or start directly with latin coding
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# more info see:
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# https://web.archive.org/web/20160528181353/http://partners.adobe.com/public/developer/en/ps/5002.EPSF_Spec.pdf
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offset = i32(s, 4)
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length = i32(s, 8)
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else:
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raise SyntaxError("not an EPS file")
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return (length, offset)
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def load(self, scale=1):
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# Load EPS via Ghostscript
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if not self.tile:
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return
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self.im = Ghostscript(self.tile, self.size, self.fp, scale)
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self.mode = self.im.mode
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self._size = self.im.size
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self.tile = []
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def load_seek(self, *args, **kwargs):
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# we can't incrementally load, so force ImageFile.parser to
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# use our custom load method by defining this method.
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pass
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#
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# --------------------------------------------------------------------
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def _save(im, fp, filename, eps=1):
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"""EPS Writer for the Python Imaging Library."""
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#
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# make sure image data is available
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im.load()
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#
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# determine PostScript image mode
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if im.mode == "L":
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operator = (8, 1, "image")
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elif im.mode == "RGB":
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operator = (8, 3, "false 3 colorimage")
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elif im.mode == "CMYK":
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operator = (8, 4, "false 4 colorimage")
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else:
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raise ValueError("image mode is not supported")
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base_fp = fp
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wrapped_fp = False
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if fp != sys.stdout:
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fp = io.TextIOWrapper(fp, encoding="latin-1")
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wrapped_fp = True
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try:
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if eps:
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#
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# write EPS header
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fp.write("%!PS-Adobe-3.0 EPSF-3.0\n")
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fp.write("%%Creator: PIL 0.1 EpsEncode\n")
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# fp.write("%%CreationDate: %s"...)
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fp.write("%%%%BoundingBox: 0 0 %d %d\n" % im.size)
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fp.write("%%Pages: 1\n")
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fp.write("%%EndComments\n")
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fp.write("%%Page: 1 1\n")
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fp.write("%%ImageData: %d %d " % im.size)
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fp.write('%d %d 0 1 1 "%s"\n' % operator)
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#
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# image header
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fp.write("gsave\n")
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fp.write("10 dict begin\n")
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fp.write(f"/buf {im.size[0] * operator[1]} string def\n")
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fp.write("%d %d scale\n" % im.size)
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fp.write("%d %d 8\n" % im.size) # <= bits
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fp.write(f"[{im.size[0]} 0 0 -{im.size[1]} 0 {im.size[1]}]\n")
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fp.write("{ currentfile buf readhexstring pop } bind\n")
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fp.write(operator[2] + "\n")
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if hasattr(fp, "flush"):
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fp.flush()
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ImageFile._save(im, base_fp, [("eps", (0, 0) + im.size, 0, None)])
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fp.write("\n%%%%EndBinary\n")
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fp.write("grestore end\n")
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if hasattr(fp, "flush"):
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fp.flush()
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finally:
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if wrapped_fp:
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fp.detach()
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#
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# --------------------------------------------------------------------
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Image.register_open(EpsImageFile.format, EpsImageFile, _accept)
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Image.register_save(EpsImageFile.format, _save)
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Image.register_extensions(EpsImageFile.format, [".ps", ".eps"])
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Image.register_mime(EpsImageFile.format, "application/postscript")
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