Image PII Redaction with OCR
Source: anonym.community research
Summary
Research Source Scanned Documents Bypass Text-Based PII Detection Entirely anonym.community March 2026 crawl View Source Organizations digitize paper records by scanning, creating image files (PNG, JPEG, TIFF) and scanned PDFs. These contain PII visible to humans but invisible to text-based PII detection. Names, addresses, government IDs, and medical information in scanned documents pass through every text-based anonymization tool undetected. OCR (Optical Character Recognition) bridges this gap by extracting text from images for PII detection.
Evidence & Data Points
- Organizations digitize paper records by scanning, creating image files (PNG, JPEG, TIFF) and scanned PDFs. These contain PII visible to humans but invisible to text-based PII detection. Names, addresses, government IDs, and medical information in scanned documents pass through every text-based anony
Solution
The Solution: How cloak.business Addresses This Tesseract OCR Engine cloak.business uses Tesseract OCR to extract text from images with 95%+ accuracy on clean documents. Supports 37 languages including Latin, Cyrillic, CJK, Arabic, and Devanagari scripts. EXIF auto-orientation ensures correct text extraction regardless of image rotation. Bounding-Box Redaction Detected PII regions are redacted with black rectangles precisely positioned over the text. Adjacent boxes are automatically merged to prevent partial character visibility. The document layout, non-PII content, and formatting remain intact. Supported Formats and Limits PNG, JPEG/JPG, TIFF, BMP, WebP, and GIF. Maximum 10MB per image, 150MP maximum resolution. Batch processing available via API and MCP Server (analyze_image and redact_
Compliance Context
Compliance Mapping This feature addresses GDPR Article 4(1) (personal data in any form — including images), HIPAA §164.514 (de-identification of scanned medical records), and archival/FOIA requirements where scanned government documents must be redacted before public release. cloak.business's GDPR, HIPAA, PCI-DSS, ISO 27001, SOC 2 compliance coverage, combined with Customer-selected hosting, provides documented technical measures organizations can reference in their compliance documentation.