Source code for PIL.EpsImagePlugin

#
# 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.
#
from __future__ import annotations

import io
import os
import re
import subprocess
import sys
import tempfile

from . import Image, ImageFile
from ._binary import i32le as i32
from ._deprecate import deprecate

# --------------------------------------------------------------------


split = re.compile(r"^%%([^:]*):[ \t]*(.*)[ \t]*$")
field = re.compile(r"^%[%!\w]([^:]*)[ \t]*$")

gs_binary = None
gs_windows_binary = None


[docs] def has_ghostscript(): global gs_binary, gs_windows_binary if gs_binary is None: if sys.platform.startswith("win"): if gs_windows_binary is None: 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 gs_binary = gs_windows_binary else: try: subprocess.check_call(["gs", "--version"], stdout=subprocess.DEVNULL) gs_binary = "gs" except OSError: gs_binary = False return gs_binary is not False
[docs] def Ghostscript(tile, size, fp, scale=1, transparency=False): """Render an image using Ghostscript""" global gs_binary if not has_ghostscript(): msg = "Unable to locate Ghostscript on paths" raise OSError(msg) # Unpack decoder tile decoder, tile, offset, data = tile[0] length, bbox = data # Hack to support hi-res rendering scale = int(scale) or 1 width = size[0] * scale height = size[1] * scale # resolution is dependent on bbox and size res_x = 72.0 * width / (bbox[2] - bbox[0]) res_y = 72.0 * height / (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) device = "pngalpha" if transparency else "ppmraw" # Build Ghostscript command command = [ gs_binary, "-q", # quiet mode f"-g{width:d}x{height:d}", # set output geometry (pixels) f"-r{res_x:f}x{res_y:f}", # set input DPI (dots per inch) "-dBATCH", # exit after processing "-dNOPAUSE", # don't pause between pages "-dSAFER", # safe mode f"-sDEVICE={device}", f"-sOutputFile={outfile}", # output file # adjust for image origin "-c", f"{-bbox[0]} {-bbox[1]} translate", "-f", infile, # input file # showpage (see https://bugs.ghostscript.com/show_bug.cgi?id=698272) "-c", "showpage", ] # 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) out_im = Image.open(outfile) out_im.load() finally: try: os.unlink(outfile) if infile_temp: os.unlink(infile_temp) except OSError: pass im = out_im.im.copy() out_im.close() return im
[docs] class PSFile: """ Wrapper for bytesio object that treats either CR or LF as end of line. This class is no longer used internally, but kept for backwards compatibility. """ def __init__(self, fp): deprecate( "PSFile", 11, action="If you need the functionality of this class " "you will need to implement it yourself.", ) self.fp = fp self.char = None
[docs] def seek(self, offset, whence=io.SEEK_SET): self.char = None self.fp.seek(offset, whence)
[docs] def readline(self): s = [self.char or b""] self.char = None c = self.fp.read(1) while (c not in b"\r\n") and len(c): s.append(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 b"".join(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.
[docs] 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) # go to offset - start of "%!PS" self.fp.seek(offset) self._mode = "RGB" self._size = None byte_arr = bytearray(255) bytes_mv = memoryview(byte_arr) bytes_read = 0 reading_header_comments = True reading_trailer_comments = False trailer_reached = False def check_required_header_comments(): if "PS-Adobe" not in self.info: msg = 'EPS header missing "%!PS-Adobe" comment' raise SyntaxError(msg) if "BoundingBox" not in self.info: msg = 'EPS header missing "%%BoundingBox" comment' raise SyntaxError(msg) def _read_comment(s): nonlocal reading_trailer_comments try: m = split.match(s) except re.error as e: msg = "not an EPS file" raise SyntaxError(msg) from e if m: k, v = m.group(1, 2) self.info[k] = v if k == "BoundingBox": if v == "(atend)": reading_trailer_comments = True elif not self._size or ( trailer_reached and reading_trailer_comments ): 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 return True while True: byte = self.fp.read(1) if byte == b"": # if we didn't read a byte we must be at the end of the file if bytes_read == 0: break elif byte in b"\r\n": # if we read a line ending character, ignore it and parse what # we have already read. if we haven't read any other characters, # continue reading if bytes_read == 0: continue else: # ASCII/hexadecimal lines in an EPS file must not exceed # 255 characters, not including line ending characters if bytes_read >= 255: # only enforce this for lines starting with a "%", # otherwise assume it's binary data if byte_arr[0] == ord("%"): msg = "not an EPS file" raise SyntaxError(msg) else: if reading_header_comments: check_required_header_comments() reading_header_comments = False # reset bytes_read so we can keep reading # data until the end of the line bytes_read = 0 byte_arr[bytes_read] = byte[0] bytes_read += 1 continue if reading_header_comments: # Load EPS header # if this line doesn't start with a "%", # or does start with "%%EndComments", # then we've reached the end of the header/comments if byte_arr[0] != ord("%") or bytes_mv[:13] == b"%%EndComments": check_required_header_comments() reading_header_comments = False continue s = str(bytes_mv[:bytes_read], "latin-1") if not _read_comment(s): m = field.match(s) if m: k = m.group(1) if k[:8] == "PS-Adobe": self.info["PS-Adobe"] = 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: msg = "bad EPS header" raise OSError(msg) elif bytes_mv[:11] == b"%ImageData:": # Check for an "ImageData" descriptor # https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/#50577413_pgfId-1035096 # Values: # columns # rows # bit depth (1 or 8) # mode (1: L, 2: LAB, 3: RGB, 4: CMYK) # number of padding channels # block size (number of bytes per row per channel) # binary/ascii (1: binary, 2: ascii) # data start identifier (the image data follows after a single line # consisting only of this quoted value) image_data_values = byte_arr[11:bytes_read].split(None, 7) columns, rows, bit_depth, mode_id = ( int(value) for value in image_data_values[:4] ) if bit_depth == 1: self._mode = "1" elif bit_depth == 8: try: self._mode = self.mode_map[mode_id] except ValueError: break else: break self._size = columns, rows return elif trailer_reached and reading_trailer_comments: # Load EPS trailer # if this line starts with "%%EOF", # then we've reached the end of the file if bytes_mv[:5] == b"%%EOF": break s = str(bytes_mv[:bytes_read], "latin-1") _read_comment(s) elif bytes_mv[:9] == b"%%Trailer": trailer_reached = True bytes_read = 0 check_required_header_comments() if not self._size: msg = "cannot determine EPS bounding box" raise OSError(msg) def _find_offset(self, fp): s = fp.read(4) if s == b"%!PS": # for HEAD without binary preview fp.seek(0, io.SEEK_END) length = fp.tell() offset = 0 elif i32(s) == 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 s = fp.read(8) offset = i32(s) length = i32(s, 4) else: msg = "not an EPS file" raise SyntaxError(msg) return length, offset
[docs] def load(self, scale=1, transparency=False): # Load EPS via Ghostscript if self.tile: self.im = Ghostscript(self.tile, self.size, self.fp, scale, transparency) self._mode = self.im.mode self._size = self.im.size self.tile = [] return Image.Image.load(self)
[docs] 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, b"image") elif im.mode == "RGB": operator = (8, 3, b"false 3 colorimage") elif im.mode == "CMYK": operator = (8, 4, b"false 4 colorimage") else: msg = "image mode is not supported" raise ValueError(msg) if eps: # write EPS header fp.write(b"%!PS-Adobe-3.0 EPSF-3.0\n") fp.write(b"%%Creator: PIL 0.1 EpsEncode\n") # fp.write("%%CreationDate: %s"...) fp.write(b"%%%%BoundingBox: 0 0 %d %d\n" % im.size) fp.write(b"%%Pages: 1\n") fp.write(b"%%EndComments\n") fp.write(b"%%Page: 1 1\n") fp.write(b"%%ImageData: %d %d " % im.size) fp.write(b'%d %d 0 1 1 "%s"\n' % operator) # image header fp.write(b"gsave\n") fp.write(b"10 dict begin\n") fp.write(b"/buf %d string def\n" % (im.size[0] * operator[1])) fp.write(b"%d %d scale\n" % im.size) fp.write(b"%d %d 8\n" % im.size) # <= bits fp.write(b"[%d 0 0 -%d 0 %d]\n" % (im.size[0], im.size[1], im.size[1])) fp.write(b"{ currentfile buf readhexstring pop } bind\n") fp.write(operator[2] + b"\n") if hasattr(fp, "flush"): fp.flush() ImageFile._save(im, fp, [("eps", (0, 0) + im.size, 0, None)]) fp.write(b"\n%%%%EndBinary\n") fp.write(b"grestore end\n") if hasattr(fp, "flush"): fp.flush() # -------------------------------------------------------------------- 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")