rubbing-image-preparationlisted

# Rubbing Image Preparation Prepare auditable image baselines for research. Treat every output as a deterministic derivative (`DER`), never as newly recovered writing. ## Preconditions 1. Register the source and rights with `research-provenance-ledger`. 2. Keep the original file immutable and outside public serving directories. 3. Inspect untrusted downloads in quarantine before decoding them. 4. Use a Python runtime with the versions in `requirements.txt`. Read [method-policy.md](references/method-policy.md) before interpreting metrics or choosing an OCR input. Read [output-contract.md](references/output-contract.md) when another Skill will consume the manifest. Read [destain-derivation.md](references/destain-derivation.md) before removing anything from an image. ## Workflow ### 1. Inspect without deriving ```bash python3 scripts/prepare_image.py inspect \ --input /path/to/immutable-image.tif \ --output-report /path/to/inspection.json ``` Review dimensions, mode, frame count, clipping, entropy, contrast, gradient energy, and warnings. A metric describes the decoded pixels; it does not prove legibility or authenticity. ### 2. Produce deterministic baselines ```bash python3 scripts/prepare_image.py derive \ --input /path/to/immutable-image.tif \ --output-dir /path/to/new-run ``` The command refuses an existing output directory and writes: - `grayscale.png`; - `contrast.png`; - `binary-dark-foreground.png`; - `binary-light-foreground.png`; - `manifest.json`.