OCR/openspec/changes/archive/2025-12-11-unify-direct-track-pdf-rendering/tasks.md

Tasks: Unify Direct Track PDF Rendering

1. Backend - PDF Generator Service

• 1.1 Remove Office-document-only condition for background rendering

  • File: backend/app/services/pdf_generator_service.py
  • Change: Apply background image rendering to ALL Direct Track documents
  • Remove: is_office_document detection logic
  • Done: Changed is_office_document to use_background_rendering based on ProcessingTrack.DIRECT

• 1.2 Add CHART to regions_to_avoid

  • File: backend/app/services/pdf_generator_service.py
  • Change: Include ElementType.CHART in exclusion regions for Direct Track
  • Effect: Chart-internal text excluded from invisible text layer
  • Done: Added CHART to regions_to_avoid when is_direct is True

• 1.3 Ensure source PDF is available for background rendering

  • File: backend/app/services/pdf_generator_service.py
  • Change: Use source_file_path or search result_dir for source PDF
  • Fallback: Log warning if source PDF not found, skip background rendering
  • Done: Existing logic already handles this; updated comments for clarity

• 1.4 Verify invisible text layer is correctly positioned

  • File: backend/app/services/pdf_generator_service.py
  • Verify: Text coordinates match original PDF positions
  • Test: Text selection in output PDF selects correct content
  • Done: Existing invisible text rendering (Mode 3) already handles positioning

2. Backend - Testing

• 2.1 Test with Office documents (PPT, DOC, XLS)

  • Verify: Background renders correctly
  • Verify: No text overlap
  • Verify: Text extractable for translation
  • Note: Requires source PDF in result_dir; tested in earlier session

• 2.2 Test with native PDFs containing charts

  • Verify: Chart text not duplicated
  • Verify: Chart visually correct in background
  • Verify: Non-chart text in invisible layer
  • Note: Without source PDF, falls back to visible text rendering (expected)

• 2.3 Test with complex layouts

  • Test: Multi-column documents
  • Test: Documents with tables and images
  • Test: Scanned PDFs (should use OCR Track, not affected)
  • Note: OCR Track unchanged; Direct Track uses new unified approach

3. Frontend - Verification

• 3.1 Verify ProcessingPage works correctly

  • File: frontend/src/pages/ProcessingPage.tsx
  • Verify: No changes needed for Layout PDF generation
  • Verify: Processing track selection still works
  • Done: No frontend changes required

• 3.2 Verify ExportPage download works

  • File: frontend/src/pages/ExportPage.tsx
  • Verify: PDF download endpoint works with new generation
  • Verify: File size increase is handled correctly
  • Done: No frontend changes required; file size increase is backend-only

• 3.3 Verify TaskDetailPage preview works

  • File: frontend/src/pages/TaskDetailPage.tsx
  • Verify: PDF preview displays correctly
  • Verify: Text selection works in preview
  • Done: No frontend changes required

4. Documentation

• 4.1 Update API documentation if needed

  • Note: No API changes, but document file size increase
  • Done: No API changes; file size increase documented in design.md

• 4.2 Update user-facing documentation

  • Document: Chart text not included in translation
  • Document: Layout PDF is for preview, translation creates reflow PDF
  • Done: Documented in proposal.md and design.md