PDF Babel

PDF Babel - Layout-Preserving PDF Translation

Translate a PDF document while preserving the original layout (images, borders, fonts, positioning). Only the text changes.

Supported document types: blood_test, urine_test, breast_ultrasound, pet_ct, immunohistochemistry, mri, general_medical.

Step 1: Check config

Read pdf_translate_config.yaml to understand the current settings. If it doesn't exist, create one:

source .venv/Scripts/activate && python -m pdf_translator.cli init-config

Key config fields to review:

• document_type — must match the PDF being translated
• header_detection / header_fixed_y — controls what's treated as non-translatable header
• instructions — free-text guidance tailored to the document type
• phrase_translations — additional phrase-level replacements for narrative text (ultrasound reports, etc.)
• do_not_translate_patterns — regex patterns for codes to preserve (e.g. BI-RADS)

If the document type doesn't match, update the config before proceeding. For a new document type, see the manual at docs/adding-document-types.md.

Step 2: Run pipeline

The user provides a PDF path as the argument. If not given, translate all PDFs in the pdfs/ directory.

source .venv/Scripts/activate && python -m pdf_translator.cli pipeline "<PDF_PATH>"

If no PDF_PATH argument was given:

source .venv/Scripts/activate && python -m pdf_translator.cli pipeline

Step 3: Check for unknown terms

After the pipeline completes, check for untranslated text:

source .venv/Scripts/activate && python -m pdf_translator.cli check "<PDF_PATH>" --json

If the check returns an empty list [], the translation is complete — skip to Step 5.

If unknown terms are found, proceed to Step 4.

Step 4: Resolve unknown terms interactively

For EACH unknown term returned by the check command, ask the user for help. Format your question like this:

I found an untranslated term on Page {page} that I don't recognize:

Unknown text: {text}

Surrounding context: ...{context_before} → {text} → {context_after}...

What does this mean? Should I:

1. Translate it to: _____ (please provide the translation)
2. Keep it as-is (it's a name, code, or shouldn't be translated)

Wait for the user to respond to ALL unknown terms before continuing.

After getting answers, decide where each translation belongs:

• Single words / exact span matches → add to custom_translations in config
• Phrases that appear within longer narrative spans → add to phrase_translations in config
• Terms to keep as-is → add to do_not_translate in config
• Patterns to keep as-is (codes, IDs) → add to do_not_translate_patterns in config

If many unknowns share a domain (e.g. a new type of medical report), consider adding a new dictionary section in pdf_translator/translate.py instead of piling entries into the config. See docs/adding-document-types.md for the full workflow.

Then re-run the pipeline:

source .venv/Scripts/activate && python -m pdf_translator.cli pipeline "<PDF_PATH>"

Run the check again to verify no unknowns remain. Repeat if needed.

Step 5: Report completion

Tell the user:

• Output file path
• Number of spans translated
• Confirm no unknown terms remain

Translation rules

Follow the instructions field from the config. Core rules:

• Header zone: NEVER translate (clinic info, logo area, document codes)
• Patient/doctor names: Keep as-is unless name_translations are configured
• Numbers, dates, order numbers: Keep as-is
• English medical codes (WBC, NEUT#, HGB, BI-RADS, etc.): Keep as-is
• Equipment brand/model names: Keep as-is
• Gender: "Ж" → "F", "Ч" → "M"
• Measurement units: Convert Cyrillic → Latin (ммоль/л → mmol/l)
• Medical terms: Standard medical terminology in target language
• Reference intervals: Translate words, keep numbers
• Narrative text (ultrasound reports, PET-CT scans, etc.): Phrase-level translation using longest-first matching — built-in dictionaries + phrase_translations from config
• PET-CT specific: SUVmax values kept as-is, radiation units (МБк→MBq, м3в→mSv, Гр→Gy), drug names transliterated to international names
• Immunohistochemistry specific: IHC marker names (ER, PgR, Ki67, HER-2, E-Cadherin) and clone IDs kept as-is; ICD-O / SNOMED codes preserved; grading codes (G1–G3, LVI(0), PnI(0), TILs, DCIS, LCIS, RCPath, H-score) kept unchanged
• Multi-page documents: Use header_first_page_only: true in config when only page 1 has a header; set false if the clinic letterhead appears on every page
• Rotated margin text: 90-degree text on the page margins is auto-detected by the extractor and assigned zone: rotated; include rotated in preserve_zones to skip it