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jedarden 8910e934da test(bf-cc7ru): create ground truth text for degraded 200 DPI PDF fixture 
- Updated degraded-200dpi-ground-truth.txt with accurate transcription
- Matches first 2500 chars of source document (as created by PDF generation script)
- Contains Abraham Lincoln public domain text with metadata
- Verified with diff against source content
- Includes verification note at notes/bf-cc7ru.md

Acceptance criteria:
✓ Ground truth file exists in tests/fixtures/scanned/low-quality/
✓ Accurately reflects source document content (verified)
✓ Properly formatted and readable
✓ Special characters handled appropriately

Closes bf-cc7ru
2026-07-06 12:17:43 -04:00

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Verification Note: bf-cc7ru - Ground Truth Text File for Degraded Fixture

Task Completed

Created accurate ground truth text file for degraded 200 DPI PDF fixture.

What Was Done

1. Analyzed Source Content

  • Examined tests/fixtures/scanned/low-quality/source-document-abraham-lincoln-public-domain.txt
  • Reviewed the creation script create_degraded_200dpi.py to understand PDF generation
  • Confirmed the PDF contains the first 2500 characters of the source document

2. Created Ground Truth File

  • File: tests/fixtures/scanned/low-quality/degraded-200dpi-ground-truth.txt
  • Content: Exact transcription of the Abraham Lincoln public domain text
  • Size: 1967 characters (entire source document is <2500 chars)
  • Includes:
    • Title and author information
    • Introductory note with historical context
    • Public domain metadata and source attribution
    • OCR testing suitability notes

3. Verification

  • Confirmed ground truth matches source content exactly (verified with diff)
  • Character count: 1967 characters
  • File is properly formatted and readable
  • Suitable for WER (Word Error Rate) measurement against OCR output

Acceptance Criteria Status

✅ PASS - degraded-200dpi-ground-truth.txt exists in tests/fixtures/scanned/low-quality/ ✅ PASS - Ground truth text accurately reflects the source document content (verified with diff) ✅ PASS - File is properly formatted and readable by the measurement script ✅ PASS - Special characters and formatting handled appropriately (punctuation, dates, proper names)

Technical Details

The ground truth contains the complete text that would be extracted from degraded-200dpi.pdf if OCR were perfect. This includes:

  • Historical biographical text from 1909 about Abraham Lincoln
  • Dates, names, places suitable for OCR testing
  • Public domain metadata
  • Varied vocabulary and sentence structures

Files Modified

  • tests/fixtures/scanned/low-quality/degraded-200dpi-ground-truth.txt (updated)

Related Files

  • tests/fixtures/scanned/low-quality/degraded-200dpi.pdf - the degraded PDF fixture
  • tests/fixtures/scanned/low-quality/source-document-abraham-lincoln-public-domain.txt - source document
  • tests/fixtures/scanned/low-quality/create_degraded_200dpi.py - PDF generation script

Testing Notes

The ground truth file can now be used by OCR measurement scripts to calculate Word Error Rate (WER) by comparing OCR output against this known-correct text.

Generated: 2026-07-06 Bead ID: bf-cc7ru Status: COMPLETE