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OCRmyPDF/src/ocrmypdf/_sync.py
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Python

# © 2016 James R. Barlow: github.com/jbarlow83
#
# This file is part of OCRmyPDF.
#
# OCRmyPDF is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# OCRmyPDF is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with OCRmyPDF. If not, see <http://www.gnu.org/licenses/>.
import logging
import logging.handlers
import os
import sys
import threading
from collections import namedtuple
from functools import partial
from pathlib import Path
from tempfile import mkdtemp
import PIL
from ocrmypdf._concurrent import exec_progress_pool
from ocrmypdf._graft import OcrGrafter
from ocrmypdf._jobcontext import PdfContext, cleanup_working_files
from ocrmypdf._pipeline import (
convert_to_pdfa,
copy_final,
create_ocr_image,
create_pdf_page_from_image,
create_visible_page_jpg,
generate_postscript_stub,
get_orientation_correction,
get_pdfinfo,
is_ocr_required,
merge_sidecars,
metadata_fixup,
ocr_engine_hocr,
ocr_engine_textonly_pdf,
optimize_pdf,
preprocess_clean,
preprocess_deskew,
preprocess_remove_background,
rasterize,
rasterize_preview,
render_hocr_page,
should_visible_page_image_use_jpg,
triage,
validate_pdfinfo_options,
)
from ocrmypdf._plugin_manager import get_plugin_manager
from ocrmypdf._validation import (
check_requested_output_file,
create_input_file,
report_output_file_size,
)
from ocrmypdf.exceptions import ExitCode, ExitCodeException
from ocrmypdf.helpers import available_cpu_count, check_pdf, samefile
from ocrmypdf.pdfa import file_claims_pdfa
log = logging.getLogger(__name__)
PageResult = namedtuple(
'PageResult', 'pageno, pdf_page_from_image, ocr, text, orientation_correction'
)
tls = threading.local()
tls.pageno = None
def preprocess(page_context, image, remove_background, deskew, clean):
if remove_background:
image = preprocess_remove_background(image, page_context)
if deskew:
image = preprocess_deskew(image, page_context)
if clean:
image = preprocess_clean(image, page_context)
return image
old_factory = logging.getLogRecordFactory()
def record_factory(*args, **kwargs):
record = old_factory(*args, **kwargs)
if hasattr(tls, 'pageno'):
record.pageno = tls.pageno
return record
logging.setLogRecordFactory(record_factory)
def exec_page_sync(page_context):
options = page_context.options
tls.pageno = page_context.pageno + 1
orientation_correction = 0
pdf_page_from_image_out = None
ocr_out = None
text_out = None
if is_ocr_required(page_context):
if options.rotate_pages:
# Rasterize
rasterize_preview_out = rasterize_preview(page_context.origin, page_context)
orientation_correction = get_orientation_correction(
rasterize_preview_out, page_context
)
rasterize_out = rasterize(
page_context.origin,
page_context,
correction=orientation_correction,
remove_vectors=False,
)
if not any([options.clean, options.clean_final, options.remove_vectors]):
ocr_image = preprocess_out = preprocess(
page_context,
rasterize_out,
options.remove_background,
options.deskew,
clean=False,
)
else:
if not options.lossless_reconstruction:
preprocess_out = preprocess(
page_context,
rasterize_out,
options.remove_background,
options.deskew,
clean=options.clean_final,
)
if options.remove_vectors:
rasterize_ocr_out = rasterize(
page_context.origin,
page_context,
correction=orientation_correction,
remove_vectors=True,
output_tag='_ocr',
)
else:
rasterize_ocr_out = rasterize_out
ocr_image = preprocess(
page_context,
rasterize_ocr_out,
options.remove_background,
options.deskew,
clean=options.clean,
)
ocr_image_out = create_ocr_image(ocr_image, page_context)
pdf_page_from_image_out = None
if not options.lossless_reconstruction:
visible_image_out = preprocess_out
if should_visible_page_image_use_jpg(page_context.pageinfo):
visible_image_out = create_visible_page_jpg(
visible_image_out, page_context
)
visible_image_out = (
page_context.plugin_manager.hook.filter_page_image(
page=page_context, image_filename=Path(visible_image_out)
)
or visible_image_out
)
pdf_page_from_image_out = create_pdf_page_from_image(
visible_image_out, page_context
)
if options.pdf_renderer == 'hocr':
(hocr_out, text_out) = ocr_engine_hocr(ocr_image_out, page_context)
ocr_out = render_hocr_page(hocr_out, page_context)
if options.pdf_renderer == 'sandwich':
(ocr_out, text_out) = ocr_engine_textonly_pdf(ocr_image_out, page_context)
return PageResult(
pageno=page_context.pageno,
pdf_page_from_image=pdf_page_from_image_out,
ocr=ocr_out,
text=text_out,
orientation_correction=orientation_correction,
)
def post_process(pdf_file, context):
pdf_out = pdf_file
if context.options.output_type.startswith('pdfa'):
ps_stub_out = generate_postscript_stub(context)
pdf_out = convert_to_pdfa(pdf_out, ps_stub_out, context)
pdf_out = metadata_fixup(pdf_out, context)
return optimize_pdf(pdf_out, context)
def worker_init(max_pixels):
# In Windows, child process will not inherit our change to this value in
# the parent process, so ensure workers get it set. Not needed when running
# threaded, but harmless to set again.
PIL.Image.MAX_IMAGE_PIXELS = max_pixels
def exec_concurrent(context):
"""Execute the pipeline concurrently"""
# Run exec_page_sync on every page context
max_workers = min(len(context.pdfinfo), context.options.jobs)
if max_workers > 1:
log.info("Start processing %d pages concurrently", max_workers)
sidecars = [None] * len(context.pdfinfo)
ocrgraft = OcrGrafter(context)
def update_page(result, pbar):
sidecars[result.pageno] = result.text
pbar.update()
ocrgraft.graft_page(
pageno=result.pageno,
image=result.pdf_page_from_image,
textpdf=result.ocr,
autorotate_correction=result.orientation_correction,
)
pbar.update()
exec_progress_pool(
use_threads=context.options.use_threads,
max_workers=max_workers,
tqdm_kwargs=dict(
total=(2 * len(context.pdfinfo)),
desc='OCR',
unit='page',
unit_scale=0.5,
disable=not context.options.progress_bar,
),
task_initializer=partial(worker_init, PIL.Image.MAX_IMAGE_PIXELS),
task=exec_page_sync,
task_arguments=context.get_page_contexts(),
task_finished=update_page,
)
# Output sidecar text
if context.options.sidecar:
text = merge_sidecars(sidecars, context)
# Copy text file to destination
copy_final(text, context.options.sidecar, context)
# Merge layers to one single pdf
pdf = ocrgraft.finalize()
# PDF/A and metadata
pdf = post_process(pdf, context)
# Copy PDF file to destination
copy_final(pdf, context.options.output_file, context)
class NeverRaise(Exception):
"""An exception that is never raised"""
pass # pylint: disable=unnecessary-pass
def configure_debug_logging(log_filename, prefix=''):
log_file_handler = logging.FileHandler(log_filename, delay=True)
log_file_handler.setLevel(logging.DEBUG)
formatter = logging.Formatter(
'[%(asctime)s] - %(name)s - %(levelname)7s -%(pageno)s %(message)s'
)
log_file_handler.setFormatter(formatter)
logging.getLogger(prefix).addHandler(log_file_handler)
return log_file_handler
def run_pipeline(options, *, plugin_manager, api=False):
# Any changes to options will not take effect for options that are already
# bound to function parameters in the pipeline. (For example
# options.input_file, options.pdf_renderer are already bound.)
if not options.jobs:
options.jobs = available_cpu_count()
if not plugin_manager:
plugin_manager = get_plugin_manager(options.plugins)
work_folder = Path(mkdtemp(prefix="com.github.ocrmypdf."))
debug_log_handler = None
if (options.keep_temporary_files or options.verbose >= 1) and not os.environ.get(
'PYTEST_CURRENT_TEST', ''
):
debug_log_handler = configure_debug_logging(Path(work_folder) / "debug.log")
try:
check_requested_output_file(options)
start_input_file, original_filename = create_input_file(options, work_folder)
# Triage image or pdf
origin_pdf = triage(
original_filename, start_input_file, work_folder / 'origin.pdf', options
)
# Gather pdfinfo and create context
pdfinfo = get_pdfinfo(
origin_pdf,
progbar=options.progress_bar,
max_workers=options.jobs if not options.use_threads else 1, # To help debug
check_pages=options.pages,
)
context = PdfContext(options, work_folder, origin_pdf, pdfinfo, plugin_manager)
# Validate options are okay for this pdf
validate_pdfinfo_options(context)
# Execute the pipeline
exec_concurrent(context)
if options.output_file == '-':
log.info("Output sent to stdout")
elif samefile(options.output_file, os.devnull):
pass # Say nothing when sending to dev null
else:
if options.output_type.startswith('pdfa'):
pdfa_info = file_claims_pdfa(options.output_file)
if pdfa_info['pass']:
log.info(
"Output file is a %s (as expected)", pdfa_info['conformance']
)
else:
log.warning(
"Output file is okay but is not PDF/A (seems to be %s)",
pdfa_info['conformance'],
)
return ExitCode.pdfa_conversion_failed
if not check_pdf(options.output_file):
log.warning('Output file: The generated PDF is INVALID')
return ExitCode.invalid_output_pdf
report_output_file_size(options, start_input_file, options.output_file)
except (KeyboardInterrupt if not api else NeverRaise) as e:
if options.verbose >= 1:
log.exception("KeyboardInterrupt")
else:
log.error("KeyboardInterrupt")
return ExitCode.ctrl_c
except (ExitCodeException if not api else NeverRaise) as e:
if str(e):
log.error("%s: %s", type(e).__name__, str(e))
else:
log.error(type(e).__name__)
return e.exit_code
except (Exception if not api else NeverRaise) as e: # pylint: disable=broad-except
log.exception("An exception occurred while executing the pipeline")
return ExitCode.other_error
finally:
if debug_log_handler:
try:
debug_log_handler.close()
log.removeHandler(debug_log_handler)
except EnvironmentError as e:
print(e, file=sys.stderr)
cleanup_working_files(work_folder, options)
return ExitCode.ok