engine-selection

Engine-selection fixture set

This directory is the tracked, content-balanced input set for researching a deterministic auto engine choice. It is not a training corpus and it is not a watermark-oracle corpus.

Content matrix

content-manifest.csv contains 19 prompt-matched pairs. Each pair uses the same prompt and generation index across OpenAI gpt-image-1-mini and Meta muse-image-1.0, covering the content classes that materially stress image regeneration:

• natural and urban scenes;
• single-person portraits and people in context;
• animals, food, products, interiors, architecture, macro detail, and action;
• flat, isometric, watercolor, and surreal illustration styles.

The files are exact copies of generation outputs collected for the docs/arxiv-paper-review research branch. The manifest records the SHA-256 of the committed bytes. The old OpenAI collection manifest stored the API payload hash under sha256; source_payload_sha256 preserves that value while sha256 always means the actual file bytes here. Meta's two hashes are the same.

The project maintainer has cleared these exact committed outputs for permanent public test and benchmark reuse. reuse_basis records that clearance on every row. It is permission for this fixed fixture set, not a claim that either provider grants a general-purpose dataset license for arbitrary generations.

One generation per prompt and provider is enough for the first paired discovery pass. Any policy inferred from it must be challenged against unused generation indices from the local research archive before shipping. Generated outputs belong outside this directory.

carrier-manifest.csv adds the canonical, already tracked signal carriers to the study without copying their bytes. Together the two manifests cover ordinary content, text, single faces, face grids, and mixed face/text scenes.

Signal carriers

The content matrix was re-encoded by its collection pipeline and has no local provenance signal. It must not be used to set or certify watermark-removal strengths. The tracked oracle/carrier inputs remain in their canonical homes:

• OpenAI and Google SynthID: data/synthid/originals/ with data/synthid/manifest.csv;
• Meta Content Seal: data/contentseal/originals/ with data/contentseal/manifest.csv.

A publication-cleared Microsoft Paint InvisMark carrier is tracked at data/fixtures/provenance/microsoft-paint-invismark.png; its source and MIT license are recorded in data/image-watermark-examples.csv and data/licenses/. It does not by itself certify an engine-selection row. That requires a fresh paired oracle check, including a pixel-identical metadata-stripped control that remains positive in Microsoft's detector.

Integrity check

Run:

uv run python scripts/verify_engine_selection_fixtures.py

The check validates paths, byte hashes, dimensions, prompt pairing, and the declared provider/content matrix without loading any ML model.