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Direktori : /usr/lib/python3/dist-packages/PIL/ |
Current File : //usr/lib/python3/dist-packages/PIL/PdfImagePlugin.py |
# # 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")