graft: remove separate implementation of unparse_content_stream

This commit is contained in:
James R. Barlow
2021-09-15 00:25:06 -07:00
parent b4b32a35b5
commit 79fe7a0a85
+38 -50
View File
@@ -11,8 +11,19 @@ from contextlib import suppress
from pathlib import Path
from typing import Optional
import pikepdf
from pikepdf.objects import Dictionary, Name
from pikepdf import (
Dictionary,
Name,
Object,
Operator,
Page,
Pdf,
PdfError,
PdfMatrix,
Stream,
parse_content_stream,
unparse_content_stream,
)
log = logging.getLogger(__name__)
MAX_REPLACE_PAGES = 100
@@ -47,51 +58,28 @@ def strip_invisible_text(pdf, page):
render_mode = 0
text_objects = []
rich_page = pikepdf.Page(page)
rich_page = Page(page)
rich_page.contents_coalesce()
for operands, operator in pikepdf.parse_content_stream(page, ''):
for operands, operator in parse_content_stream(page, ''):
if not in_text_obj:
if operator == pikepdf.Operator('BT'):
if operator == Operator('BT'):
in_text_obj = True
render_mode = 0
text_objects.append((operands, operator))
else:
stream.append((operands, operator))
else:
if operator == pikepdf.Operator('Tr'):
if operator == Operator('Tr'):
render_mode = operands[0]
text_objects.append((operands, operator))
if operator == pikepdf.Operator('ET'):
if operator == Operator('ET'):
in_text_obj = False
if render_mode != 3:
stream.extend(text_objects)
text_objects.clear()
def convert(op):
try:
return op.unparse()
except AttributeError:
return str(op).encode('ascii')
if hasattr(pikepdf, 'unparse_content_stream'):
content_stream = pikepdf.unparse_content_stream(stream)
else:
lines = []
for operands, operator in stream:
if operator == pikepdf.Operator('INLINE IMAGE'):
iim = operands[0]
line = iim.unparse()
else:
line = (
b' '.join(convert(op) for op in operands)
+ b' '
+ operator.unparse()
)
lines.append(line)
content_stream = b'\n'.join(lines)
page.Contents = pikepdf.Stream(pdf, content_stream)
content_stream = unparse_content_stream(stream)
page.Contents = Stream(pdf, content_stream)
class OcrGrafter:
@@ -99,14 +87,14 @@ class OcrGrafter:
self.context = context
self.path_base = context.origin
self.pdf_base = pikepdf.open(self.path_base)
self.pdf_base = Pdf.open(self.path_base)
self.font, self.font_key = None, None
self.pdfinfo = context.pdfinfo
self.output_file = context.get_path('graft_layers.pdf')
self.procset = self.pdf_base.make_indirect(
pikepdf.Object.parse(b'[ /PDF /Text /ImageB /ImageC /ImageI ]')
Object.parse(b'[ /PDF /Text /ImageB /ImageC /ImageI ]')
)
self.emplacements = 1
@@ -130,7 +118,7 @@ class OcrGrafter:
# We are updating the old page with a rasterized PDF of the new
# page (without changing objgen, to preserve references)
log.debug("Emplacement update")
with pikepdf.open(image) as pdf_image:
with Pdf.open(path_image) as pdf_image:
self.emplacements += 1
foreign_image_page = pdf_image.pages[0]
self.pdf_base.pages.append(foreign_image_page)
@@ -203,7 +191,7 @@ class OcrGrafter:
self.pdf_base.save(next_file)
self.pdf_base.close()
self.pdf_base = pikepdf.open(next_file)
self.pdf_base = Pdf.open(next_file)
self.procset = self.pdf_base.pages[0].Resources.ProcSet
self.font, self.font_key = None, None # Ensure we reacquire this information
self.interim_count += 1
@@ -219,7 +207,7 @@ class OcrGrafter:
font, font_key = None, None
possible_font_names = ('/f-0-0', '/F1')
try:
with pikepdf.open(text) as pdf_text:
with Pdf.open(text) as pdf_text:
try:
pdf_text_fonts = pdf_text.pages[0].Resources.get('/Font', {})
except (AttributeError, IndexError, KeyError):
@@ -233,7 +221,7 @@ class OcrGrafter:
if pdf_text_font:
font = self.pdf_base.copy_foreign(pdf_text_font)
return font, font_key
except (FileNotFoundError, pikepdf.PdfError):
except (FileNotFoundError, PdfError):
# PdfError occurs if a 0-length file is written e.g. due to OCR timeout
return None, None
@@ -242,9 +230,9 @@ class OcrGrafter:
*,
page_num: int,
textpdf: Path,
font: pikepdf.Object,
font_key: pikepdf.Object,
procset: pikepdf.Object,
font: Object,
font_key: Object,
procset: Object,
text_rotation: int,
strip_old_text: bool,
):
@@ -255,7 +243,7 @@ class OcrGrafter:
return
# This is a pointer indicating a specific page in the base file
with pikepdf.open(textpdf) as pdf_text:
with Pdf.open(textpdf) as pdf_text:
pdf_text_contents = pdf_text.pages[0].Contents.read_bytes()
base_page = self.pdf_base.pages.p(page_num)
@@ -270,13 +258,13 @@ class OcrGrafter:
mediabox = [float(base_page.MediaBox[v]) for v in range(4)]
wp, hp = mediabox[2] - mediabox[0], mediabox[3] - mediabox[1]
translate = pikepdf.PdfMatrix().translated(-wt / 2, -ht / 2)
untranslate = pikepdf.PdfMatrix().translated(wp / 2, hp / 2)
corner = pikepdf.PdfMatrix().translated(mediabox[0], mediabox[1])
translate = PdfMatrix().translated(-wt / 2, -ht / 2)
untranslate = PdfMatrix().translated(wp / 2, hp / 2)
corner = PdfMatrix().translated(mediabox[0], mediabox[1])
# -rotation because the input is a clockwise angle and this formula
# uses CCW
text_rotation = -text_rotation % 360
rotate = pikepdf.PdfMatrix().rotated(text_rotation)
rotate = PdfMatrix().rotated(text_rotation)
# Because of rounding of DPI, we might get a text layer that is not
# identically sized to the target page. Scale to adjust. Normally this
@@ -287,7 +275,7 @@ class OcrGrafter:
scale_y = hp / ht
# log.debug('%r', scale_x, scale_y)
scale = pikepdf.PdfMatrix().scaled(scale_x, scale_y)
scale = PdfMatrix().scaled(scale_x, scale_y)
# Translate the text so it is centered at (0, 0), rotate it there, adjust
# for a size different between initial and text PDF, then untranslate, and
@@ -310,14 +298,14 @@ class OcrGrafter:
pdf_draw_xobj = (
(b'q %s cm\n' % ctm.encode()) + (b'%s Do\n' % text_xobj_name) + b'\nQ\n'
)
new_text_layer = pikepdf.Stream(self.pdf_base, pdf_draw_xobj)
new_text_layer = Stream(self.pdf_base, pdf_draw_xobj)
if strip_old_text:
strip_invisible_text(self.pdf_base, base_page)
if hasattr(pikepdf.Page, 'contents_add'):
if hasattr(Page, 'contents_add'):
# pikepdf >= 2.14 adds this method and deprecates the one below
pikepdf.Page(base_page).contents_add(new_text_layer, prepend=True)
Page(base_page).contents_add(new_text_layer, prepend=True)
else:
# pikepdf < 2.14
base_page.page_contents_add(