jbig2_lossy is deprecated and will be ignored. Lossy JBIG2 h

Error message

jbig2_lossy is deprecated and will be ignored. Lossy JBIG2 has been removed due to character substitution risks.

What it means

Lossy JBIG2 encoding was removed from OCRmyPDF due to character substitution risks (lossy JBIG2 can swap visually similar characters). Passing jbig2_lossy=True now only triggers this warning; the option is discarded.

Source

Thrown at src/ocrmypdf/api.py:837

                'input_file',
                'output_file',
                'kwargs',
                'plugin_manager',
            }
        }
        create_options_kwargs.update(kwargs)

        parser = get_parser()
        with _plugin_session(plugins, plugin_manager, parser=parser) as plugin_manager:
            if 'verbose' in kwargs:
                warn(
                    "ocrmypdf.ocr(verbose=) is ignored. "
                    "Use ocrmypdf.configure_logging()."
                )

            # Warn about deprecated jbig2 options and remove from kwargs
            if jbig2_lossy:
                warn(
                    "jbig2_lossy is deprecated and will be ignored. "
                    "Lossy JBIG2 has been removed due to character substitution risks."
                )
                create_options_kwargs.pop('jbig2_lossy', None)
            if jbig2_page_group_size:
                warn("jbig2_page_group_size is deprecated and will be ignored.")
                create_options_kwargs.pop('jbig2_page_group_size', None)

            options = create_options(
                input_file=input_file,
                output_file=output_file,
                parser=parser,
                **create_options_kwargs,
            )
            check_options(options, plugin_manager)
            return run_pipeline(options=options, plugin_manager=plugin_manager)

View on GitHub (pinned to 5074a0b0e1)

Solutions

Remove jbig2_lossy from your call — it does nothing now
Use standard (lossless) JBIG2 if the encoder is available, or accept higher file size
If size matters, tune jpeg_quality instead for image-only pages

Example fix

# before
ocrmypdf.ocr('in.pdf', 'out.pdf', jbig2_lossy=True)
# after
ocrmypdf.ocr('in.pdf', 'out.pdf')  # lossy JBIG2 removed for correctness

Defensive patterns

Strategy: validation

Validate before calling

kwargs.pop('jbig2_lossy', None)

Prevention

Remove removed options from shared config dicts after upgrades
Use lossless compression settings only

When it happens

Trigger: Calling ocrmypdf.ocr(..., jbig2_lossy=True); the argument is popped from create_options_kwargs after warning.

Common situations: Scripts written for older OCRmyPDF versions that supported lossy JBIG2 compression; users chasing smaller file sizes for scanned documents.

Related errors

AI-assisted analysis of ocrmypdf/OCRmyPDF@5074a0b0e1 (2026-08-27). Data as JSON: /api/errors/14b06780bfd3539b. Report an issue: GitHub.