Turn the verified-text fidelity anchor off by default

The whole-frame 15% Qwen-VAE blend returned detector-visible OpenAI
SynthID on poster-scale manifests through the engine text-manifest
path (official Content Provenance API, 2026-08-19: restored detected
x6 with the anchor, clean x6 without it; base outputs clean x6;
pixel-identical stripped controls detected, proving the pixel channel).
Add fidelity_anchor=False to remove_watermark and InvisibleOptions and
--fidelity-anchor on the CLI to reproduce the 0.27.0 research
behavior. Text-box MAE cost of the new default is under one point on
all three fixtures (11.60->11.72, 7.79->7.86, 7.57->8.13).

src/remove_ai_watermarks/__init__.py

@@ -32,7 +32,7 @@ _os.environ.setdefault("TRANSFORMERS_VERBOSITY", "error")
 _warnings.filterwarnings("ignore", message=r".*ImageProcessorFast.*")
 
 
-__version__ = "0.27.0"
+__version__ = "0.27.1"
 
 __all__ = [
     "BatchSummary",

src/remove_ai_watermarks/_internal/qwen_zimage_pipeline.py

@@ -1071,6 +1071,7 @@ class QwenZImagePipeline:
         tile_size: int = 1024,
         tile_overlap: int = 128,
         text_manifest: VerifiedTextManifest | None = None,
+        fidelity_anchor: bool = False,
     ) -> Image.Image:
         """Execute global regeneration and masked face repair."""
         self._require_cuda()
@@ -1120,7 +1121,16 @@ class QwenZImagePipeline:
             restore_verified_text,
         )
 
-        self._progress("Blending the Qwen-VAE fidelity anchor...")
-        anchor = blend_fidelity_anchor(result, donor)
+        # The anchor is OFF by default since 0.27.1: blending 15% of the Qwen-VAE
+        # donor ACROSS THE WHOLE FRAME returned detector-visible OpenAI SynthID on
+        # poster-scale manifests (official Content Provenance API, 2026-08-19:
+        # detected x6 with the anchor, clean x6 without it, base clean throughout;
+        # see docs/text-protection-research.md). ``fidelity_anchor=True`` keeps the
+        # 0.27.0 research behavior for reproduction.
+        if fidelity_anchor:
+            self._progress("Blending the Qwen-VAE fidelity anchor...")
+            anchor = blend_fidelity_anchor(result, donor)
+        else:
+            anchor = result
         self._progress(f"Restoring {len(text_manifest.lines)} verified text lines...")
         return restore_verified_text(image, anchor, donor, text_manifest.lines)

src/remove_ai_watermarks/api.py

@@ -244,6 +244,7 @@ class InvisibleOptions:
     tile_size: int = 1024
     tile_overlap: int = 128
     text_manifest: Path | None = None
+    fidelity_anchor: bool = False
 
 
 # What the invisible stage did. "unavailable" is the one outcome the caller must
@@ -525,6 +526,7 @@ def _run_invisible(
         tile_size=opts.tile_size,
         tile_overlap=opts.tile_overlap,
         text_manifest=opts.text_manifest,
+        fidelity_anchor=opts.fidelity_anchor,
     )
     say("invisible", "removed")
     return "removed"

src/remove_ai_watermarks/cli.py

@@ -321,6 +321,16 @@ _text_manifest_option = click.option(
     ),
 )
 
+_fidelity_anchor_option = click.option(
+    "--fidelity-anchor/--no-fidelity-anchor",
+    default=False,
+    help=(
+        "With --text-manifest: blend 15% of the Qwen-VAE donor across the whole "
+        "frame. Off by default - the global blend was measured to return "
+        "detector-visible OpenAI SynthID on poster-scale manifests."
+    ),
+)
+
 
 _visible_backend_option = click.option(
     "--backend",
@@ -798,6 +808,7 @@ def cmd_erase(
 @_force_option
 @_cpu_offload_option
 @_text_manifest_option
+@_fidelity_anchor_option
 @click.pass_context
 def cmd_invisible(
     ctx: click.Context,
@@ -818,6 +829,7 @@ def cmd_invisible(
     force: bool,
     cpu_offload: bool,
     text_manifest: Path | None,
+    fidelity_anchor: bool,
 ) -> None:
     """Remove invisible AI watermarks (SynthID, StableSignature, TreeRing).
 
@@ -880,6 +892,7 @@ def cmd_invisible(
             tile_size=tile_size,
             tile_overlap=tile_overlap,
             text_manifest=text_manifest,
+            fidelity_anchor=fidelity_anchor,
         )
     except (OSError, RuntimeError, ValueError) as exc:
         console.print(f"  Error: {exc}")
@@ -1428,6 +1441,7 @@ def cmd_identify(ctx: click.Context, source: Path, no_visible: bool, as_json: bo
 @_force_option
 @_cpu_offload_option
 @_text_manifest_option
+@_fidelity_anchor_option
 @click.pass_context
 def cmd_all(
     ctx: click.Context,
@@ -1450,6 +1464,7 @@ def cmd_all(
     force: bool,
     cpu_offload: bool,
     text_manifest: Path | None,
+    fidelity_anchor: bool,
 ) -> None:
     """Remove ALL watermarks: visible + invisible + metadata.
 
@@ -1528,6 +1543,7 @@ def cmd_all(
                 tile_size=tile_size,
                 tile_overlap=tile_overlap,
                 text_manifest=text_manifest,
+                fidelity_anchor=fidelity_anchor,
             ),
             force=force,
             progress=progress,

src/remove_ai_watermarks/invisible_engine.py

@@ -150,6 +150,7 @@ class InvisibleEngine:
         tile_size: int = 1024,
         tile_overlap: int = 128,
         text_manifest: Path | None = None,
+        fidelity_anchor: bool = False,
     ) -> Path:
         """Remove invisible watermark from an image.
 
@@ -187,6 +188,13 @@ class InvisibleEngine:
                 Requires the ``text-restoration`` extra and the ``qwen-zimage``
                 profile. Incompatible with tiling, downscaling, humanize, unsharp,
                 and adaptive polish because those combinations are not calibrated.
+            fidelity_anchor: Blend 15% of the Qwen-VAE donor across the whole frame
+                before glyph restoration. OFF by default since 0.27.1: that global
+                blend was measured to return detector-visible OpenAI SynthID on
+                poster-scale manifests (detected x6 with the anchor vs clean x6
+                without it, base clean; official Content Provenance API,
+                2026-08-19 - docs/text-protection-research.md). ``True`` reproduces
+                the 0.27.0 research behavior. Requires ``text_manifest``.
 
         Returns:
             Path to the cleaned image.
@@ -196,6 +204,8 @@ class InvisibleEngine:
         seed = resolve_seed(seed)
         adaptive_polish = resolve_adaptive_polish(adaptive_polish, self._remover.model_profile)
 
+        if fidelity_anchor and text_manifest is None:
+            raise ValueError("fidelity_anchor requires a text manifest")
         if text_manifest is not None:
             if self._remover.model_profile != QWEN_ZIMAGE_PROFILE:
                 raise ValueError("--text-manifest is supported only by the qwen-zimage profile")
@@ -270,6 +280,7 @@ class InvisibleEngine:
                 tile_size=tile_size,
                 tile_overlap=tile_overlap,
                 text_manifest=verified_text,
+                fidelity_anchor=fidelity_anchor,
             )
 
             # Post-processing chain: decode the diffusion output ONCE, apply the