# SANS Courseware Watermark Remover

Removes personalized SANS “Licensed To …” watermarks (names, emails, hashes, dates) by deleting the actual `BT…ET` text objects in the PDF—no white boxes, no selection artefacts.

## Quickstart

1. **(If encrypted) Decrypt first with `qpdf`:**
   
   ```bash
   qpdf --password='<YOUR_PASSWORD>' --decrypt INPUT.pdf INPUT_unlocked.pdf
   ```

2. **Install dependencies (Python 3.9+):**

   ```bash
   python -m venv .venv
   source .venv/bin/activate            # Windows: .venv\Scripts\activate
   pip install -r requirements.txt
   ```

3. **Run the sanitizer (auto-creates `<input>_clean.pdf`):**
4. 
   ```bash
   # Recommended latest script:
   python enhanced_sanitize_pdf.py INPUT_unlocked.pdf
   ```

## Notes

* The tool targets common SANS watermark patterns:
  * Invisible 36-pt text with rendering modes 1/3,
  * Rotated diagonal overlay using −25-pt fonts,
  * Footer lines at 10/18-pt.
* If your course PDFs use different fonts/sizes, adjust the regex patterns inside the script.