Harden TrustMark detection with an official fixture

data/README.md

@@ -6,6 +6,7 @@ Tracked data is organized by purpose:
 data/
   fixtures/
     provenance/   Real format and provenance fixtures used by tests
+                  (source records live in fixtures/README.md)
   calibration/
     <vendor>/     Minimal controlled inputs needed to rebuild detector assets
   synthid/
@@ -31,7 +32,9 @@ data/
    commands, hashes, and oracle verdicts instead of committing another corpus
    copy. A small curated before-and-after example may live in `docs/images/`
    when it is part of the public documentation.
-6. Runtime detector assets belong in `src/remove_ai_watermarks/assets/`.
+6. Keep third-party fixture license notices in `licenses/`, outside directories
+   that tests enumerate as media inputs.
+7. Runtime detector assets belong in `src/remove_ai_watermarks/assets/`.
    Unregistered research candidates belong in
    `scripts/assets/visible-mark-candidates/` so they are not shipped in the
    wheel.

data/fixtures/README.md

@@ -0,0 +1,15 @@
+# Provenance fixtures
+
+These files exercise real container, metadata, and pixel-provenance formats.
+They are test inputs, not evaluation corpora.
+
+## Adobe TrustMark
+
+`adobe-trustmark-p.png` is Adobe's official `images/ghost_P.png` Variant P
+example from [`adobe/trustmark`](https://github.com/adobe/trustmark) at commit
+`0ed40cbe8188f664fd9cbbeacd969807de27440a`.
+
+- Source: `https://raw.githubusercontent.com/adobe/trustmark/0ed40cbe8188f664fd9cbbeacd969807de27440a/images/ghost_P.png`
+- SHA-256: `e58c5825ed7e5d9fb04710ea541b61bd55879cad65554c0d46260aa24b3d0755`
+- Expected signal: TrustMark Variant P, schema 1
+- License: MIT, reproduced in `../licenses/adobe-trustmark-MIT.txt`

data/licenses/adobe-trustmark-MIT.txt

@@ -0,0 +1,25 @@
+Copyright 2023 Adobe
+All Rights Reserved.
+
+NOTICE: Adobe permits you to use, modify, and distribute this file in
+accordance with the terms of the license agreement accompanying it.
+
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.