ai-content-maker/.venv/Lib/site-packages/PIL/PdfImagePlugin.py

304 lines
8.6 KiB
Python

#
# The Python Imaging Library.
# $Id$
#
# PDF (Acrobat) file handling
#
# History:
# 1996-07-16 fl Created
# 1997-01-18 fl Fixed header
# 2004-02-21 fl Fixes for 1/L/CMYK images, etc.
# 2004-02-24 fl Fixes for 1 and P images.
#
# Copyright (c) 1997-2004 by Secret Labs AB. All rights reserved.
# Copyright (c) 1996-1997 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#
##
# Image plugin for PDF images (output only).
##
from __future__ import annotations
import io
import math
import os
import time
from . import Image, ImageFile, ImageSequence, PdfParser, __version__, features
#
# --------------------------------------------------------------------
# object ids:
# 1. catalogue
# 2. pages
# 3. image
# 4. page
# 5. page contents
def _save_all(im, fp, filename):
_save(im, fp, filename, save_all=True)
##
# (Internal) Image save plugin for the PDF format.
def _write_image(im, filename, existing_pdf, image_refs):
# FIXME: Should replace ASCIIHexDecode with RunLengthDecode
# (packbits) or LZWDecode (tiff/lzw compression). Note that
# PDF 1.2 also supports Flatedecode (zip compression).
params = None
decode = None
#
# Get image characteristics
width, height = im.size
dict_obj = {"BitsPerComponent": 8}
if im.mode == "1":
if features.check("libtiff"):
filter = "CCITTFaxDecode"
dict_obj["BitsPerComponent"] = 1
params = PdfParser.PdfArray(
[
PdfParser.PdfDict(
{
"K": -1,
"BlackIs1": True,
"Columns": width,
"Rows": height,
}
)
]
)
else:
filter = "DCTDecode"
dict_obj["ColorSpace"] = PdfParser.PdfName("DeviceGray")
procset = "ImageB" # grayscale
elif im.mode == "L":
filter = "DCTDecode"
# params = f"<< /Predictor 15 /Columns {width-2} >>"
dict_obj["ColorSpace"] = PdfParser.PdfName("DeviceGray")
procset = "ImageB" # grayscale
elif im.mode == "LA":
filter = "JPXDecode"
# params = f"<< /Predictor 15 /Columns {width-2} >>"
procset = "ImageB" # grayscale
dict_obj["SMaskInData"] = 1
elif im.mode == "P":
filter = "ASCIIHexDecode"
palette = im.getpalette()
dict_obj["ColorSpace"] = [
PdfParser.PdfName("Indexed"),
PdfParser.PdfName("DeviceRGB"),
len(palette) // 3 - 1,
PdfParser.PdfBinary(palette),
]
procset = "ImageI" # indexed color
if "transparency" in im.info:
smask = im.convert("LA").getchannel("A")
smask.encoderinfo = {}
image_ref = _write_image(smask, filename, existing_pdf, image_refs)[0]
dict_obj["SMask"] = image_ref
elif im.mode == "RGB":
filter = "DCTDecode"
dict_obj["ColorSpace"] = PdfParser.PdfName("DeviceRGB")
procset = "ImageC" # color images
elif im.mode == "RGBA":
filter = "JPXDecode"
procset = "ImageC" # color images
dict_obj["SMaskInData"] = 1
elif im.mode == "CMYK":
filter = "DCTDecode"
dict_obj["ColorSpace"] = PdfParser.PdfName("DeviceCMYK")
procset = "ImageC" # color images
decode = [1, 0, 1, 0, 1, 0, 1, 0]
else:
msg = f"cannot save mode {im.mode}"
raise ValueError(msg)
#
# image
op = io.BytesIO()
if filter == "ASCIIHexDecode":
ImageFile._save(im, op, [("hex", (0, 0) + im.size, 0, im.mode)])
elif filter == "CCITTFaxDecode":
im.save(
op,
"TIFF",
compression="group4",
# use a single strip
strip_size=math.ceil(width / 8) * height,
)
elif filter == "DCTDecode":
Image.SAVE["JPEG"](im, op, filename)
elif filter == "JPXDecode":
del dict_obj["BitsPerComponent"]
Image.SAVE["JPEG2000"](im, op, filename)
else:
msg = f"unsupported PDF filter ({filter})"
raise ValueError(msg)
stream = op.getvalue()
if filter == "CCITTFaxDecode":
stream = stream[8:]
filter = PdfParser.PdfArray([PdfParser.PdfName(filter)])
else:
filter = PdfParser.PdfName(filter)
image_ref = image_refs.pop(0)
existing_pdf.write_obj(
image_ref,
stream=stream,
Type=PdfParser.PdfName("XObject"),
Subtype=PdfParser.PdfName("Image"),
Width=width, # * 72.0 / x_resolution,
Height=height, # * 72.0 / y_resolution,
Filter=filter,
Decode=decode,
DecodeParms=params,
**dict_obj,
)
return image_ref, procset
def _save(im, fp, filename, save_all=False):
is_appending = im.encoderinfo.get("append", False)
if is_appending:
existing_pdf = PdfParser.PdfParser(f=fp, filename=filename, mode="r+b")
else:
existing_pdf = PdfParser.PdfParser(f=fp, filename=filename, mode="w+b")
dpi = im.encoderinfo.get("dpi")
if dpi:
x_resolution = dpi[0]
y_resolution = dpi[1]
else:
x_resolution = y_resolution = im.encoderinfo.get("resolution", 72.0)
info = {
"title": (
None if is_appending else os.path.splitext(os.path.basename(filename))[0]
),
"author": None,
"subject": None,
"keywords": None,
"creator": None,
"producer": None,
"creationDate": None if is_appending else time.gmtime(),
"modDate": None if is_appending else time.gmtime(),
}
for k, default in info.items():
v = im.encoderinfo.get(k) if k in im.encoderinfo else default
if v:
existing_pdf.info[k[0].upper() + k[1:]] = v
#
# make sure image data is available
im.load()
existing_pdf.start_writing()
existing_pdf.write_header()
existing_pdf.write_comment(f"created by Pillow {__version__} PDF driver")
#
# pages
ims = [im]
if save_all:
append_images = im.encoderinfo.get("append_images", [])
for append_im in append_images:
append_im.encoderinfo = im.encoderinfo.copy()
ims.append(append_im)
number_of_pages = 0
image_refs = []
page_refs = []
contents_refs = []
for im in ims:
im_number_of_pages = 1
if save_all:
try:
im_number_of_pages = im.n_frames
except AttributeError:
# Image format does not have n_frames.
# It is a single frame image
pass
number_of_pages += im_number_of_pages
for i in range(im_number_of_pages):
image_refs.append(existing_pdf.next_object_id(0))
if im.mode == "P" and "transparency" in im.info:
image_refs.append(existing_pdf.next_object_id(0))
page_refs.append(existing_pdf.next_object_id(0))
contents_refs.append(existing_pdf.next_object_id(0))
existing_pdf.pages.append(page_refs[-1])
#
# catalog and list of pages
existing_pdf.write_catalog()
page_number = 0
for im_sequence in ims:
im_pages = ImageSequence.Iterator(im_sequence) if save_all else [im_sequence]
for im in im_pages:
image_ref, procset = _write_image(im, filename, existing_pdf, image_refs)
#
# page
existing_pdf.write_page(
page_refs[page_number],
Resources=PdfParser.PdfDict(
ProcSet=[PdfParser.PdfName("PDF"), PdfParser.PdfName(procset)],
XObject=PdfParser.PdfDict(image=image_ref),
),
MediaBox=[
0,
0,
im.width * 72.0 / x_resolution,
im.height * 72.0 / y_resolution,
],
Contents=contents_refs[page_number],
)
#
# page contents
page_contents = b"q %f 0 0 %f 0 0 cm /image Do Q\n" % (
im.width * 72.0 / x_resolution,
im.height * 72.0 / y_resolution,
)
existing_pdf.write_obj(contents_refs[page_number], stream=page_contents)
page_number += 1
#
# trailer
existing_pdf.write_xref_and_trailer()
if hasattr(fp, "flush"):
fp.flush()
existing_pdf.close()
#
# --------------------------------------------------------------------
Image.register_save("PDF", _save)
Image.register_save_all("PDF", _save_all)
Image.register_extension("PDF", ".pdf")
Image.register_mime("PDF", "application/pdf")