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OCRmyPDF/src/ocrmypdf/_pipelines/hocr_to_ocr_pdf.py
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James R. Barlow 580252a1a0 Merge branch 'feature/gscan2pdf'
Reconcile release notes and copy_final() with new pipeline.
2023-10-30 00:01:28 -07:00

135 lines
4.3 KiB
Python

# SPDX-FileCopyrightText: 2019-2023 James R. Barlow
# SPDX-FileCopyrightText: 2019 Martin Wind
# SPDX-License-Identifier: MPL-2.0
"""Implements the concurrent and page synchronous parts of the pipeline."""
from __future__ import annotations
import argparse
import logging
import logging.handlers
from collections.abc import Sequence
from functools import partial
import PIL
from ocrmypdf._concurrent import Executor
from ocrmypdf._graft import OcrGrafter
from ocrmypdf._jobcontext import PageContext, PdfContext
from ocrmypdf._pipeline import (
copy_final,
get_pdfinfo,
render_hocr_page,
)
from ocrmypdf._pipelines._common import (
HOCRResult,
manage_work_folder,
postprocess,
report_output_pdf,
set_thread_pageno,
setup_pipeline,
worker_init,
)
from ocrmypdf._plugin_manager import OcrmypdfPluginManager
from ocrmypdf._progressbar import ProgressBar
from ocrmypdf.exceptions import ExitCode
log = logging.getLogger(__name__)
def _exec_hocrtransform_sync(page_context: PageContext) -> HOCRResult:
"""Process each page."""
hocr_json = page_context.get_path('hocr.json')
if not hocr_json.exists():
# No hOCR file, so no OCR was performed on this page.
return HOCRResult(pageno=page_context.pageno)
hocr_result = HOCRResult.from_json(hocr_json.read_text())
hocr_result.textpdf = render_hocr_page(
page_context.get_path('ocr_hocr.hocr'), page_context
)
return hocr_result
def exec_hocr_to_ocr_pdf(context: PdfContext, executor: Executor) -> Sequence[str]:
"""Convert hOCR files to OCR PDF."""
# Run exec_page_sync on every page
options = context.options
max_workers = min(len(context.pdfinfo), options.jobs)
if max_workers > 1:
log.info("Continue processing %d pages concurrently", max_workers)
ocrgraft = OcrGrafter(context)
def graft_page(result: HOCRResult, pbar: ProgressBar):
"""Graft text only PDF on to main PDF's page."""
try:
set_thread_pageno(result.pageno + 1)
pbar.update()
ocrgraft.graft_page(
pageno=result.pageno,
image=result.pdf_page_from_image,
textpdf=result.textpdf,
autorotate_correction=result.orientation_correction,
)
pbar.update()
finally:
set_thread_pageno(None)
executor(
use_threads=options.use_threads,
max_workers=max_workers,
progress_kwargs=dict(
total=(2 * len(context.pdfinfo)),
desc='Grafting hOCR to PDF',
unit='page',
unit_scale=0.5,
disable=not options.progress_bar,
),
worker_initializer=partial(worker_init, PIL.Image.MAX_IMAGE_PIXELS),
task=_exec_hocrtransform_sync,
task_arguments=context.get_page_context_args(),
task_finished=graft_page,
)
pdf = ocrgraft.finalize()
messages: Sequence[str] = []
if options.output_type != 'none':
# PDF/A and metadata
log.info("Postprocessing...")
pdf, messages = postprocess(pdf, context, executor)
# Copy PDF file to destination (we don't know the input PDF file name)
copy_final(pdf, options.output_file, None)
return messages
def run_hocr_to_ocr_pdf_pipeline(
options: argparse.Namespace,
*,
plugin_manager: OcrmypdfPluginManager,
) -> ExitCode:
"""Run pipeline to convert hOCR to final output PDF."""
with manage_work_folder(
work_folder=options.work_folder, retain=True, print_location=False
) as work_folder:
executor = setup_pipeline(options, plugin_manager)
origin_pdf = work_folder / 'origin.pdf'
# Gather pdfinfo and create context
pdfinfo = get_pdfinfo(
origin_pdf,
executor=executor,
detailed_analysis=options.redo_ocr,
progbar=options.progress_bar,
max_workers=options.jobs,
use_threads=options.use_threads,
check_pages=options.pages,
)
context = PdfContext(options, work_folder, origin_pdf, pdfinfo, plugin_manager)
plugin_manager.hook.check_options(options=options)
optimize_messages = exec_hocr_to_ocr_pdf(context, executor)
return report_output_pdf(options, origin_pdf, optimize_messages)