Working HOCR folder to PDF converter

src/ocrmypdf/__init__.py

@@ -11,7 +11,7 @@ from ocrmypdf import helpers, hocrtransform, pdfa, pdfinfo
 from ocrmypdf._concurrent import Executor
 from ocrmypdf._jobcontext import PageContext, PdfContext
 from ocrmypdf._version import PROGRAM_NAME, __version__
-from ocrmypdf.api import Verbosity, configure_logging, ocr, pdf_to_hocr
+from ocrmypdf.api import Verbosity, configure_logging, hocr_to_ocr_pdf, ocr, pdf_to_hocr
 from ocrmypdf.exceptions import (
     BadArgsError,
     DpiError,
@@ -40,6 +40,7 @@ __all__ = [
     'ExitCode',
     'ExitCodeException',
     'helpers',
+    'hocr_to_ocr_pdf',
     'hocrtransform',
     'hookimpl',
     'InputFileError',
@@ -49,6 +50,7 @@ __all__ = [
     'OrientationConfidence',
     'OutputFileAccessError',
     'PageContext',
+    'pdf_to_hocr',
     'pdfa',
     'PdfContext',
     'pdfinfo',

src/ocrmypdf/_pipelines/common.py

@@ -108,7 +108,11 @@ class HOCRResult:
     def __getstate__(self):
         """Return state values to be pickled."""
         return {
-            k: (str(v) if k in ('pdf_page_from_image', 'hocr', 'textpdf') else v)
+            k: (
+                ('Path://' + str(v))
+                if k in ('pdf_page_from_image', 'hocr', 'textpdf') and v is not None
+                else v
+            )
             for k, v in self.__dict__.items()
         }
 
@@ -116,7 +120,11 @@ class HOCRResult:
         """Restore state from the unpickled state values."""
         self.__dict__.update(
             {
-                k: (Path(v) if k in ('pdf_page_from_image', 'hocr', 'textpdf') else v)
+                k: (
+                    Path(v.removeprefix('Path://'))
+                    if k in ('pdf_page_from_image', 'hocr', 'textpdf') and v is not None
+                    else v
+                )
                 for k, v in state.items()
             }
         )

src/ocrmypdf/_pipelines/hocr_to_ocr_pdf.py

@@ -114,26 +114,22 @@ def run_hocr_to_ocr_pdf_pipeline(
     plugin_manager: OcrmypdfPluginManager,
 ) -> ExitCode:
     with manage_work_folder(
-        work_folder=options.input_folder, retain=True, print_location=False
+        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'
-        shutil.copy2(options.input_file, origin_pdf)
 
         # Gather pdfinfo and create context
         pdfinfo = get_pdfinfo(
-            options.input_file,
+            origin_pdf,
             executor=executor,
             detailed_analysis=options.redo_ocr,
             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, options.input_file, pdfinfo, plugin_manager
-        )
-        # Validate options are okay for this pdf
-        validate_pdfinfo_options(context)
+        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)

src/ocrmypdf/api.py

@@ -20,6 +20,7 @@ from warnings import warn
 import pluggy
 
 from ocrmypdf._logging import PageNumberFilter
+from ocrmypdf._pipelines.hocr_to_ocr_pdf import run_hocr_to_ocr_pdf_pipeline
 from ocrmypdf._plugin_manager import get_plugin_manager
 from ocrmypdf._sync import run_hocr_pipeline, run_pipeline, run_pipeline_cli
 from ocrmypdf._validation import check_options
@@ -454,6 +455,63 @@ def pdf_to_hocr(
         return run_hocr_pipeline(options=options, plugin_manager=plugin_manager)
 
 
+def hocr_to_ocr_pdf(
+    work_folder: Path,
+    output_file: Path,
+    *,
+    jobs: int | None = None,
+    use_threads: bool | None = None,
+    optimize: int | None = None,
+    jpg_quality: int | None = None,
+    png_quality: int | None = None,
+    jbig2_lossy: bool | None = None,
+    jbig2_page_group_size: int | None = None,
+    jbig2_threshold: float | None = None,
+    pdfa_image_compression: str | None = None,
+    color_conversion_strategy: str | None = None,
+    fast_web_view: float | None = None,
+    plugin_manager=None,
+    plugins: Iterable[StrPath] | None = None,
+    **kwargs,
+):
+    """Run OCRmyPDF and produces an output folder containing hOCR files."""
+    # No new variable names should be assigned until these two steps are run
+    create_options_kwargs = {
+        k: v
+        for k, v in locals().items()
+        if k not in {'work_folder', 'output_pdf', 'kwargs'}
+    }
+    create_options_kwargs.update(kwargs)
+
+    parser = get_parser()
+
+    with _api_lock:
+        # We can't allow multiple ocrmypdf.ocr() threads to run in parallel, because
+        # they might install different plugins, and generally speaking we have areas
+        # of code that use global state.
+
+        if not plugin_manager:
+            plugin_manager = get_plugin_manager(plugins)
+        plugin_manager.hook.add_options(parser=parser)  # pylint: disable=no-member
+
+        cmdline, deferred = _kwargs_to_cmdline(
+            defer_kwargs={'work_folder', 'output_file', 'plugins'},
+            **create_options_kwargs,
+        )
+        cmdline.append(str(work_folder))
+        cmdline.append(str(output_file))
+        parser.enable_api_mode()
+        options = parser.parse_args(cmdline)
+        for keyword, val in deferred.items():
+            setattr(options, keyword, val)
+        delattr(options, 'input_file')
+        setattr(options, 'work_folder', work_folder)
+
+        return run_hocr_to_ocr_pdf_pipeline(
+            options=options, plugin_manager=plugin_manager
+        )
+
+
 __all__ = [
     'PageNumberFilter',
     'Verbosity',
@@ -466,4 +524,5 @@ __all__ = [
     'pdf_to_hocr',
     'run_pipeline',
     'run_pipeline_cli',
+    'hocr_to_ocr_pdf',
 ]

tests/test_api.py

@@ -39,3 +39,19 @@ def test_hocr_api(resources: Path, outdir: Path):
     assert (outdir / '000006_ocr_hocr.hocr').exists()
 
     assert not (outdir / '000004_ocr_hocr.hocr').exists()
+
+
+def test_hocr_to_pdf_api(resources: Path, outdir: Path, outpdf: Path):
+    ocrmypdf.pdf_to_hocr(
+        resources / 'ccitt.pdf',
+        outdir,
+        language='eng',
+        skip_text=True,
+        plugins=['tests/plugins/tesseract_cache.py'],
+    )
+    assert (outdir / '000001_ocr_hocr.hocr').exists()
+    hocr = (outdir / '000001_ocr_hocr.hocr').read_text(encoding='utf-8')
+    mangled = hocr.replace('the', 'hocr')
+    (outdir / '000001_ocr_hocr.hocr').write_text(mangled, encoding='utf-8')
+
+    ocrmypdf.hocr_to_ocr_pdf(outdir, outpdf)