mirror of
https://github.com/wiltodelta/remove-ai-watermarks.git
synced 2026-06-05 02:28:00 +02:00
fix(invisible): disable protect-text/protect-faces by default; add docs/synthid.md
Both text and face protection were shielding SynthID from removal. The text-protection high-res re-scrub regenerates pixels at an upscaled resolution where the per-region pass may not be strong enough to re-destroy the SynthID payload, allowing it to survive in text areas. Face protection has an even more direct mechanism: it pastes back the original (pre-diffusion, watermarked) face pixels after the global pass, guaranteeing SynthID survives in face regions regardless of strength. Both --protect-text and --protect-faces are now off by default and opt-in. Rename from --no-protect-text / --no-protect-faces to --protect-text / --protect-faces. Extract shared click.option decorators to module-level constants (_protect_text_option, _protect_faces_option) to eliminate copy-paste between cmd_invisible and cmd_all. Add docs/synthid.md: primary-source-cited technical reference for SynthID-Image covering mechanism (post-hoc encoder/decoder, 136-bit payload, pixel-space, no model-weight modification), robustness numbers (arXiv:2510.09263: ~99.98% TPR at 0.1% FPR across 30 transforms), removal attacks and forensic detectability (arXiv:2605.09203: all 6 attacks detectable >98% TPR@1%FPR), detectability limits, oracle scope, adoption landscape, and practical implications including the protect-text/faces SynthID-preservation finding. Verified June 2026 on gpt-image 1600x1600 via openai.com/verify: with --protect-text SynthID detected; without, SynthID removed. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
@@ -116,7 +116,7 @@ image → encode to latent space (VAE) at native resolution
|
||||
|
||||
> **Default strength is `0.30`, tuned to remove the current Google SynthID.** An oracle-verified study (fresh Gemini images, "Verify with SynthID") found the current SynthID survives `0.10`/`0.15`/`0.20` and clears only at `0.30`. SynthID is a moving target (the threshold has climbed `0.05` → `0.10` → `~0.30` as Google hardens it), and there is no local SynthID detector, so the tool cannot self-check and auto-tune. If the oracle still reads SynthID, raise `--strength` further; if you care more about preserving fine text, lower it. `0.30` softens dense typography somewhat, so use the lowest value that comes back clean on the oracle.
|
||||
>
|
||||
> **Keep text protection on (the default) — it does not block SynthID removal.** SynthID is a global watermark, so strength `0.30` clears it whether or not text is protected, and text protection keeps headings and body text readable through the pass (only the very finest print still softens at `0.30`). You do not need to disable it for removal; `--no-protect-text` only trades text quality for a faster run.
|
||||
> **Text and face protection are OFF by default.** The high-resolution text re-scrub can shield SynthID in text regions, leaving the watermark intact there even after the global pass clears it everywhere else (verified June 2026: same image, with `--protect-text` → SynthID detected; without → SynthID removed). Both features are opt-in with `--protect-text` / `--protect-faces` and considered **experimental**. If you enable them, verify the result with the oracle.
|
||||
>
|
||||
> **OpenAI / ChatGPT images do not carry Google SynthID** (they use C2PA metadata, stripped by the metadata step), so `0.30` is overkill there; `--strength 0.10` preserves quality and the metadata strip is what matters.
|
||||
>
|
||||
@@ -126,11 +126,13 @@ SDXL is the default since May 2026: empirically defeats SynthID v2 on Gemini 3 P
|
||||
|
||||
> **Oracle vs `identify` can disagree, and that is expected.** An online verifier reads the actual SynthID *pixel* watermark and detects only its own vendor's content — [openai.com/research/verify](https://openai.com/research/verify/) states "OpenAI generation signals will only be detected if the image was generated with our tools". Our `identify` cannot decode the pixel watermark (no vendor ships a local decoder), so it infers SynthID from the **C2PA metadata** instead. So after the SDXL pass the oracle can read "no SynthID" (pixel watermark gone) while `identify` still reports SynthID from a surviving C2PA manifest. They measure different signals. Run `metadata --remove` (or `all`) to also strip the manifest; note that a quiet metadata proxy is not proof the pixel watermark itself is gone.
|
||||
|
||||
**Face Protection**: before diffusion, YOLO detects people in the image and extracts them. After diffusion, the original faces are blended back with a soft elliptical mask to prevent AI distortion of facial features. Pass `--no-protect-faces` to skip the detector entirely (useful when the image has no people).
|
||||
> **Technical deep-dive:** see [`docs/synthid.md`](docs/synthid.md) for a primary-source-cited breakdown of how SynthID works mechanically (post-hoc encoder/decoder, 136-bit payload, pixel-space embedding), what it empirically survives (JPEG, crop, resize: ~99.98% TPR at 0.1% FPR from arXiv:2510.09263), what removes it, and the forensic-stealth tradeoff (all known removal attacks are detectable at >98% TPR@1%FPR per arXiv:2605.09203).
|
||||
|
||||
**Face Protection** (experimental, opt-in `--protect-faces`): before diffusion, YOLO detects people in the image and extracts them; after diffusion the original faces are blended back. Off by default — enable only when face fidelity matters more than SynthID removal completeness.
|
||||
|
||||
**Analog Humanizer**: optional film grain and chromatic aberration injection that mimics a photo of a screen, raising the bar for AI-generated image classifiers. (It frustrates generic classifiers but does not guarantee forensic invisibility — see the [arXiv:2605.09203](https://arxiv.org/abs/2605.09203) note above.)
|
||||
|
||||
**Text Protection** (automatic): SDXL img2img regenerates every pixel, so small text and glyphs get deformed at the strengths that defeat SynthID. The SDXL pipeline guards against this by default: a PP-OCRv3 text detector (a 2.4 MB ONNX model run on CPU via OpenCV's DNN module, downloaded and cached on first use) locates text regions, and if any are found the whole image is scrubbed normally and then each text block is **re-scrubbed at high resolution** and composited back. Because the text is regenerated (not copied), the watermark is still removed inside it, while running the text region at higher resolution keeps small strokes crisp through the regeneration. Detection is **language-agnostic** (it finds text regions, not characters), so Latin, Cyrillic, CJK, Hangul, Arabic, and digits are all protected, and it runs at the image's native resolution so small text on large images is not missed. Text-free images run the standard pass at no extra cost. Pass `--no-protect-text` to turn it off. SDXL default pipeline only.
|
||||
**Text Protection** (experimental, opt-in `--protect-text`): re-scrubs detected text blocks at high resolution after the global pass to keep small glyphs crisp. **Off by default** because the high-resolution re-scrub can preserve SynthID in text regions even after the global pass removes it elsewhere. Enable only when text fidelity matters more than watermark removal completeness, and verify the oracle result. SDXL pipeline only.
|
||||
|
||||
### Stripping C2PA, EXIF, and "Made with AI" metadata
|
||||
|
||||
|
||||
+429
@@ -0,0 +1,429 @@
|
||||
# SynthID-Image: technical reference
|
||||
|
||||
This document covers how Google SynthID for images works mechanically, what it
|
||||
survives, what removes it, and the current deployment landscape. It is written
|
||||
for engineers working on watermark detection and removal -- specifically to
|
||||
inform decisions about strength settings, test methodology, and what oracle
|
||||
results mean.
|
||||
|
||||
Primary sources are cited inline. Marketing-only claims are flagged separately
|
||||
from independently-verified results.
|
||||
|
||||
---
|
||||
|
||||
## 1. Mechanism
|
||||
|
||||
### 1.1 Post-hoc, model-independent design
|
||||
|
||||
SynthID-Image is **not** baked into a diffusion model's weights. It is a
|
||||
post-hoc, model-independent system: a separate encoder `f` is applied to an
|
||||
already-generated image, and a separate decoder `g` reads it back.
|
||||
|
||||
> "We deliberately designed SynthID-Image as a post-hoc, model-independent
|
||||
> approach, a choice largely based on deployment considerations."
|
||||
> -- Gowal et al., arXiv:2510.09263
|
||||
|
||||
The formal definition from the paper:
|
||||
|
||||
> "A post-hoc watermarking scheme is a pair f, g consisting of an encoder
|
||||
> function f: X -> X, which adds an identification mark, and a decoder
|
||||
> function g: X -> {+-1}, which tries to detect if the mark is present."
|
||||
|
||||
This is the key architectural fact: **the generative model (Imagen, Gemini's
|
||||
image model) is not modified**. The watermark is stamped onto the pixel output
|
||||
after generation, by a separate neural network. This means:
|
||||
|
||||
- The watermark is in **pixel space**, not in the model's latent activations.
|
||||
- Replacing the generative model does not remove the watermarking capability.
|
||||
- The encoder/decoder pair can be updated independently of the generative model.
|
||||
|
||||
The paper does not disclose the internal architecture of the encoder/decoder
|
||||
networks (layer types, capacity). The external variant SynthID-O is available
|
||||
to partners; the production internal variant is not published.
|
||||
|
||||
### 1.2 How it differs from classical DWT-DCT watermarks
|
||||
|
||||
The open watermarks used by Stable Diffusion / SDXL / FLUX (via the
|
||||
`imwatermark` library) use classical **DWT-DCT** frequency-domain embedding: a
|
||||
fixed bit pattern is added to specific frequency coefficients of the image's
|
||||
wavelet transform. This is fast, key-free, and locally detectable with a public
|
||||
decoder.
|
||||
|
||||
SynthID-Image uses **jointly-trained deep learning models**:
|
||||
|
||||
> "SynthID uses two deep learning models -- for watermarking and identifying --
|
||||
> that have been trained together on a diverse set of images. The combined model
|
||||
> is optimised on a range of objectives, including correctly identifying
|
||||
> watermarked content and improving imperceptibility by visually aligning the
|
||||
> watermark to the original content."
|
||||
> -- Google DeepMind blog, 2023
|
||||
|
||||
The practical difference for robustness: the deep learning encoder learns to
|
||||
spread the signal across the image in a way that is optimized to survive a
|
||||
specific perturbation distribution seen during training. Classical DWT-DCT
|
||||
embeds in fixed, predictable frequency bins, making it brittle to any
|
||||
operation that hits those bins (e.g., JPEG re-quantization wipes it cleanly at
|
||||
quality <= 90).
|
||||
|
||||
### 1.3 Payload capacity
|
||||
|
||||
SynthID-O (the external/partnership variant) encodes:
|
||||
|
||||
- **136 bits** within a **512x512 pixel image**
|
||||
|
||||
For comparison (from the same paper):
|
||||
|
||||
| Method | Bits | Resolution |
|
||||
|-------------|------|------------|
|
||||
| SynthID-O | 136 | 512x512 |
|
||||
| StegaStamp | 100 | 400x400 |
|
||||
| TrustMark | 100 | 256x256 |
|
||||
| WAM | 32 | 256x256 |
|
||||
|
||||
The payload carries an identification mark (not a user-readable secret). The
|
||||
paper separates watermark **detection** (is this watermarked?) from payload
|
||||
**recovery** (what does the payload say?): the detection path is what oracles
|
||||
like the Gemini app's "Verify with SynthID" exercise.
|
||||
|
||||
### 1.4 Where in the pipeline it lives
|
||||
|
||||
```
|
||||
[Diffusion model]
|
||||
|
|
||||
raw pixel output
|
||||
|
|
||||
[SynthID encoder f] <-- separate neural net, stamps the watermark
|
||||
|
|
||||
watermarked image
|
||||
|
|
||||
[served / downloaded]
|
||||
|
|
||||
[SynthID decoder g] <-- separate neural net, run by Google's verifier only
|
||||
|
|
||||
present / not present
|
||||
```
|
||||
|
||||
The VAE decoder of the diffusion model is **not** involved in watermarking.
|
||||
Some in-generation watermark approaches (like the research method "Tree Ring")
|
||||
inject the signal into the initial noise latent so it propagates through the
|
||||
diffusion process and appears in the final image; SynthID-Image does not do
|
||||
this -- it is applied after the VAE has already decoded latents to pixels.
|
||||
|
||||
---
|
||||
|
||||
## 2. Robustness
|
||||
|
||||
### 2.1 What the paper claims it survives (primary-source verified)
|
||||
|
||||
The SynthID-Image paper (arXiv:2510.09263) evaluates SynthID-O against **30
|
||||
image transformations** grouped into 6 categories:
|
||||
|
||||
| Category | Examples |
|
||||
|-------------|-----------------------------------------------|
|
||||
| Color | brightness, contrast, saturation, hue shifts |
|
||||
| Combination | combinations of multiple transforms |
|
||||
| Noise | Gaussian noise, impulse noise, median filter |
|
||||
| Overlay | text overlays, logos, stickers |
|
||||
| Quality | JPEG compression, WebP, format conversion |
|
||||
| Spatial | crop, resize, rotate, flip, padding |
|
||||
|
||||
**TPR at 0.1% FPR -- SynthID-O vs. baselines (resized to 512x512):**
|
||||
|
||||
| Category | SynthID-O | Best baseline (WAM) | Worst baseline (StegaStamp spatial) |
|
||||
|------------------|-----------|---------------------|--------------------------------------|
|
||||
| Identity (none) | 100.00% | 100.00% | 100.00% |
|
||||
| Aggregated | 99.98% | 90.62% | ~70% |
|
||||
| Color | 100.00% | 81.29% | ~75% |
|
||||
| Combination | 99.96% | 96.08% | ~22% |
|
||||
| Noise | 99.98% | 100.00% | ~92% |
|
||||
| Overlay | 100.00% | 100.00% | 100.00% |
|
||||
| Quality | 99.99% | -- | ~89% |
|
||||
| Spatial (worst) | 99.97% | 76.04% | 15.25% |
|
||||
|
||||
The "Spatial worst" row is the hardest case (aggressive crop + resize).
|
||||
SynthID-O retains 99.97% TPR; StegaStamp collapses to 15.25%. This is where
|
||||
the deep-learning approach gains the most over classical methods.
|
||||
|
||||
Google's marketing page states the watermark is:
|
||||
|
||||
> "designed to stand up to modifications like cropping, adding filters, changing
|
||||
> frame rates, or lossy compression."
|
||||
> -- deepmind.google/models/synthid/
|
||||
|
||||
The marketing claim is broadly consistent with the paper's numbers for these
|
||||
specific categories.
|
||||
|
||||
**JPEG and format conversion specifically** fall under the "Quality" category,
|
||||
where SynthID-O achieves 99.99% TPR. This is the empirical basis for the fact
|
||||
that **GitHub-recompressed JPEGs from issue attachments are valid SynthID test
|
||||
subjects**: the re-encoding does not remove the pixel watermark.
|
||||
|
||||
### 2.2 Stated limits (vendor claim, not independently verified)
|
||||
|
||||
> "SynthID isn't foolproof against extreme image manipulations."
|
||||
> -- Google DeepMind blog, 2023
|
||||
|
||||
This is the only public failure-mode statement Google has made. No specific
|
||||
perturbation type, threshold, or quantitative boundary is named. The
|
||||
Limitations section of the paper (Section 10) was not recoverable from the
|
||||
public HTML version of arXiv:2510.09263v1 due to a rendering failure in the
|
||||
conversion (the body text of Section 10 is absent from the HTML).
|
||||
|
||||
**What is known empirically from independent work and our own testing:**
|
||||
|
||||
- **Diffusion regeneration / img2img** at sufficient strength degrades or
|
||||
removes the watermark. Our testing (May-June 2026, Gemini oracle):
|
||||
- strength 0.05: insufficient for current Gemini SynthID (survives)
|
||||
- strength 0.10: removes Gemini SynthID (verified via Gemini app oracle, n=1)
|
||||
- strength 0.30: current DEFAULT; removes Gemini SynthID (verified n=3 via
|
||||
Gemini app oracle on fresh Gemini images, June 2026 oracle study)
|
||||
- strength 0.30: **does NOT reliably remove OpenAI gpt-image SynthID on
|
||||
1600x1600 images** (verified via openai.com/verify, issue #14 reports,
|
||||
June 2026)
|
||||
- strength 0.35 and 0.40: not yet oracle-verified on 1600x1600 gpt-image;
|
||||
0.40 visibly corrupts text-heavy images
|
||||
- **Resolution dependence confirmed**: same strength removes watermark on
|
||||
small images (376x429) but not on large ones (1600x1600) -- larger images
|
||||
appear to carry a stronger or more spatially distributed signal
|
||||
- The production SynthID has been progressively hardened: 0.05 worked earlier
|
||||
(pre-May 2026 Gemini), then 0.10 was needed, now 0.30 for Gemini and still
|
||||
failing at 0.30 for 1600x1600 gpt-image. It is a moving target.
|
||||
|
||||
- **Heavy JPEG compression** (quality < ~50-60): not specifically tested with
|
||||
oracle verification; the DL approach is more robust than DWT-DCT but Google
|
||||
acknowledges limits at "extreme" manipulation.
|
||||
|
||||
### 2.3 Removal attacks and forensic detectability
|
||||
|
||||
The paper arXiv:2605.09203 ("Removing the Watermark Is Not Enough",
|
||||
Goonatilake & Ateniese, 2026) evaluates 6 removal attacks against a ResNet-50
|
||||
forensic detector. All attacks defeat the watermark verifier but are detected
|
||||
by the forensic classifier:
|
||||
|
||||
| Attack | Family | AUROC | TPR @ 1% FPR | TPR @ 0.1% FPR |
|
||||
|-----------------|------------------|--------|--------------|----------------|
|
||||
| UnMarker | Distortion | 0.9994 | 99.81% | 98.28% |
|
||||
| WatermarkAttacker| Regeneration | 0.9997 | 99.95% | 99.38% |
|
||||
| CtrlRegen+ | Regeneration | 0.9999 | 99.97% | 99.64% |
|
||||
| NFPA | Inversion/Pert. | 0.9984 | 99.24% | 62.10% |
|
||||
| Boundary Leak. | Inversion/Pert. | 0.9991 | 99.24% | 88.34% |
|
||||
| WiTS | Erosion | 0.9999 | 99.80% | 99.55% |
|
||||
|
||||
The forensic detector is a standard ResNet-50 fine-tuned end-to-end; no exotic
|
||||
architecture needed. The key finding:
|
||||
|
||||
> "These removers do not return images to a clean forensic state. They often
|
||||
> trade an explicit watermark for an implicit watermark: a detectable artifact
|
||||
> introduced by the removal process itself."
|
||||
|
||||
This means: even when our SDXL img2img pass defeats the SynthID pixel
|
||||
watermark (oracle reads negative), the output may still be classifiable as
|
||||
"an image that went through a removal pipeline" by an independent detector --
|
||||
even if that detector is not trained on SynthID specifically. **Defeating the
|
||||
verifier does not restore forensic deniability.**
|
||||
|
||||
CtrlRegen+ is the most detectable removal method (AUROC 0.9999), which is
|
||||
notable because it is also the most powerful removal attack. The paper notes
|
||||
that diffusion regeneration "leaves a strong reconstruction signature from the
|
||||
diffusion prior."
|
||||
|
||||
---
|
||||
|
||||
## 3. Detectability and verifier access
|
||||
|
||||
### 3.1 No public local detector
|
||||
|
||||
The SynthID decoder is proprietary and not released:
|
||||
|
||||
> "SynthID-Image has been used to watermark over ten billion images and video
|
||||
> frames across Google's services and its corresponding verification service is
|
||||
> available to trusted testers."
|
||||
> -- Gowal et al., arXiv:2510.09263
|
||||
|
||||
There is no public API, no released decoder weights, and no reproducible
|
||||
algorithm for local detection. The verification service (SynthID Detector) is:
|
||||
|
||||
> "a verification portal" in early testing with "journalists and media
|
||||
> professionals" on a waitlist
|
||||
> -- deepmind.google/models/synthid/
|
||||
|
||||
The external variant SynthID-O is available "through partnerships" only. Our
|
||||
tool cannot locally detect SynthID presence or absence -- this is by design,
|
||||
not a gap we can fill.
|
||||
|
||||
### 3.2 How our tool detects SynthID (metadata proxy)
|
||||
|
||||
We detect SynthID indirectly: if the image's C2PA manifest is signed by a
|
||||
known SynthID-using issuer (Google, OpenAI), we infer SynthID is present. This
|
||||
is a **metadata proxy**, not a pixel watermark decode. It works while the C2PA
|
||||
manifest is intact, and is silent once the manifest is stripped or the image
|
||||
is re-encoded without C2PA (e.g., a screenshot, a social-media re-upload, or
|
||||
after `metadata --remove`).
|
||||
|
||||
This is why:
|
||||
- `identify` on a GitHub-recompressed issue attachment returns Unknown (C2PA is
|
||||
gone) even though the pixel SynthID is still present and detectable by
|
||||
openai.com/verify.
|
||||
- A quiet `identify` output is not proof that SynthID was removed -- it only
|
||||
means the metadata signal is gone.
|
||||
|
||||
### 3.3 Oracle scope: each vendor detects only their own
|
||||
|
||||
From openai.com/research/verify (verbatim, verified 2026-05-31):
|
||||
|
||||
> "OpenAI generation signals will only be detected if the image was generated
|
||||
> with our tools."
|
||||
> "Content could also still be AI-generated by another company's model, which
|
||||
> the tool currently does not detect."
|
||||
|
||||
SynthID technology is used by multiple vendors, but each verifier is keyed to
|
||||
its own payload:
|
||||
|
||||
| Oracle | Detects | Does NOT detect |
|
||||
|-------------------------------|------------------|-------------------------|
|
||||
| Gemini app "Verify with SynthID" | Google SynthID | OpenAI SynthID |
|
||||
| openai.com/research/verify | OpenAI SynthID | Google SynthID |
|
||||
|
||||
A Google-SynthID image reads clean on openai.com/verify. An OpenAI image reads
|
||||
clean in the Gemini oracle. They are different payloads within the same
|
||||
framework.
|
||||
|
||||
---
|
||||
|
||||
## 4. Adoption and current state (as of June 2026)
|
||||
|
||||
### 4.1 Google products
|
||||
|
||||
Google has watermarked **over 10 billion** images and video frames. The
|
||||
deployment split by surface matters for our tool:
|
||||
|
||||
| Surface | SynthID pixel | C2PA metadata | Visible sparkle |
|
||||
|--------------------------------------|---------------|---------------|-----------------|
|
||||
| Gemini app (generated images) | YES | YES (Google) | YES |
|
||||
| Gemini API / AI Studio / Nano Banana | YES | NO | YES |
|
||||
|
||||
The Gemini API surface is a key blind spot: it embeds the pixel watermark and
|
||||
the visible sparkle but **no C2PA or IPTC at all**. Our `identify` returns
|
||||
Unknown on API-generated images unless the visible sparkle is detected (via
|
||||
`check_visible=True`) or the user runs the Gemini app oracle.
|
||||
|
||||
### 4.2 OpenAI
|
||||
|
||||
OpenAI confirmed SynthID adoption (Help Center, updated 2026-05-21):
|
||||
|
||||
> "ChatGPT images include both C2PA metadata and SynthID watermarks."
|
||||
|
||||
This is time-gated: pre-rollout ChatGPT/gpt-image images carry C2PA without
|
||||
SynthID. Our C2PA proxy therefore over-reports SynthID presence on old images
|
||||
(hence the `_OPENAI_CAVEAT` hedging flag in the codebase).
|
||||
|
||||
### 4.3 Other vendors
|
||||
|
||||
- **Kakao** (South Korea): SynthID adopter as of May 2026 (Google announcement)
|
||||
- **NVIDIA Cosmos**: SynthID for video (not still images; different pipeline)
|
||||
- **Meta AI**: does NOT use SynthID; uses IPTC `digitalSourceType` marker instead
|
||||
|
||||
### 4.4 Version evolution (v1 vs v2 hardening)
|
||||
|
||||
Google has not publicly documented version numbers for the SynthID image
|
||||
watermark in a way that maps to our testing observations. What is known
|
||||
empirically from oracle tests:
|
||||
|
||||
- **Before May 2026 (Gemini)**: strength 0.05 removed the watermark
|
||||
- **May 2026 (Gemini)**: strength 0.05 insufficient; 0.10 required
|
||||
- **Current (Gemini, June 2026)**: strength 0.10 insufficient for fresh images;
|
||||
0.30 verified clean (Gemini app oracle, n=3, A100 GPU, native resolution)
|
||||
- **Current (OpenAI gpt-image 1600x1600, June 2026)**: strength 0.30 still
|
||||
detected by openai.com/verify (issue #14, user qw1212ss report)
|
||||
|
||||
The progression suggests Google has progressively hardened the watermark -- the
|
||||
embedding signal strength or spatial distribution has increased across model
|
||||
generations. No Google announcement confirms this; the observation is purely
|
||||
empirical from oracle tests.
|
||||
|
||||
---
|
||||
|
||||
## 5. Practical implications for this tool
|
||||
|
||||
### 5.1 Text and face protection: OFF by default
|
||||
|
||||
**Text protection (`--protect-text`) can preserve SynthID in text regions.**
|
||||
Verified June 2026 on gpt-image at 1600x1600: same image processed twice --
|
||||
with `--protect-text` the oracle detected SynthID; without it, SynthID was
|
||||
removed. The mechanism: the global img2img pass clears SynthID everywhere, but
|
||||
the text-protection high-resolution re-scrub regenerates those pixels from an
|
||||
upscaled crop. At the effective resolution of the upscaled crop, the per-region
|
||||
pass may be insufficient to re-destroy the payload, reconstituting SynthID in
|
||||
text regions.
|
||||
|
||||
**Face protection (`--protect-faces`) has an even more direct preservation
|
||||
mechanism.** The pipeline extracts face regions from the ORIGINAL (watermarked)
|
||||
image BEFORE the diffusion pass, runs the global pass (which removes SynthID
|
||||
everywhere), then blends the original face pixels BACK onto the result
|
||||
(`invisible_engine.py`: `original_faces = protector.extract_faces(cv_img)`
|
||||
before `remove_watermark`, then `protector.restore_faces(out_cv, original_faces)`
|
||||
after). Those restored pixels are the original watermarked pixels -- SynthID is
|
||||
guaranteed to survive in face regions, not just possibly. The text-protection
|
||||
case is at least re-generating (uncertain); face protection is literally
|
||||
restoring the original SynthID-bearing pixels.
|
||||
|
||||
Both `--protect-text` and `--protect-faces` are therefore **experimental and
|
||||
OFF by default**. Enable only when text/face fidelity matters more than
|
||||
watermark removal completeness, and always verify the result with the oracle.
|
||||
|
||||
### 5.2 Strength setting
|
||||
|
||||
There is no single permanent correct strength. The default 0.30 was set based
|
||||
on the June 2026 oracle study (Gemini, n=3). Known gaps:
|
||||
|
||||
- **OpenAI gpt-image at 1600x1600**: 0.30 does not clear it (oracle-verified,
|
||||
June 2026). 0.35 and 0.40 untested with oracle. 0.40 visibly corrupts text.
|
||||
- **Resolution matters**: the same strength that clears a 376x429 image fails
|
||||
at 1600x1600 (qw1212ss observation, issue #14, multiple images)
|
||||
|
||||
If the watermark survives at 0.30, the correct guidance is to try 0.35 then
|
||||
0.40, using the lowest value that reads clean on the vendor oracle.
|
||||
|
||||
### 5.3 Test methodology
|
||||
|
||||
- **GitHub-recompressed JPEGs from issue attachments are valid SynthID test
|
||||
subjects.** JPEG re-encoding removes C2PA metadata but does NOT remove the
|
||||
SynthID pixel watermark (verified June 2026 on issue #14 pic3). Do not
|
||||
dismiss these as "not faithful originals" for SynthID-removal tests.
|
||||
- **The correct oracle for OpenAI images is openai.com/verify**, not the Gemini
|
||||
app. The two oracles detect different payloads.
|
||||
- **A quiet `identify` output after processing is not proof of removal.** It
|
||||
means the metadata proxy is gone. The pixel watermark state is unknown without
|
||||
an oracle check.
|
||||
- **After removal, the output may carry forensic artifacts** detectable by an
|
||||
independent classifier even if the vendor oracle reads negative. Defeating the
|
||||
verifier is not the same as being forensically indistinguishable from clean
|
||||
content (arXiv:2605.09203).
|
||||
|
||||
### 5.4 ctrlregen and img2img: the tradeoff
|
||||
|
||||
Both the paper and our testing confirm: higher img2img strength removes the
|
||||
watermark but introduces detectable regeneration artifacts. The Goonatilake &
|
||||
Ateniese paper shows CtrlRegen+ (the most powerful remover) is simultaneously
|
||||
the most forensically detectable (AUROC 0.9999). The tradeoff is unavoidable
|
||||
with current diffusion-based approaches.
|
||||
|
||||
---
|
||||
|
||||
## References
|
||||
|
||||
1. Gowal et al. (2025). **SynthID-Image: Image watermarking at internet scale.**
|
||||
arXiv:2510.09263. https://arxiv.org/abs/2510.09263
|
||||
|
||||
2. Google DeepMind. **Identifying AI-generated images with SynthID.** Blog post,
|
||||
2023. https://deepmind.google/blog/identifying-ai-generated-images-with-synthid/
|
||||
|
||||
3. Google DeepMind. **SynthID.** Product page.
|
||||
https://deepmind.google/models/synthid/
|
||||
|
||||
4. Goonatilake & Ateniese (2026). **Removing the Watermark Is Not Enough:
|
||||
Forensic Stealth in Generative-AI Watermark Removal.** arXiv:2605.09203.
|
||||
https://arxiv.org/abs/2605.09203
|
||||
|
||||
5. OpenAI. **Verify tool for AI-generated images.** openai.com/research/verify.
|
||||
Accessed 2026-05-31.
|
||||
@@ -136,6 +136,25 @@ def _validate_image(path: Path) -> Path:
|
||||
|
||||
_ALPHA_FORMATS = {".png", ".webp"}
|
||||
|
||||
# Shared option decorators for commands that run the invisible-watermark pipeline.
|
||||
# Both cmd_invisible and cmd_all expose these flags; defining them once avoids
|
||||
# copy-paste drift.
|
||||
_protect_text_option = click.option(
|
||||
"--protect-text",
|
||||
is_flag=True,
|
||||
default=False,
|
||||
help=(
|
||||
"Enable text region protection (experimental: re-scrubs text blocks at high resolution). "
|
||||
"May prevent SynthID removal in text areas -- verify with oracle before relying on it."
|
||||
),
|
||||
)
|
||||
_protect_faces_option = click.option(
|
||||
"--protect-faces",
|
||||
is_flag=True,
|
||||
default=False,
|
||||
help="Enable face protection (experimental: YOLO detect + blend original faces back).",
|
||||
)
|
||||
|
||||
|
||||
def _watermark_region(det: DetectionResult, width: int, height: int) -> tuple[int, int, int, int]:
|
||||
"""Pick a watermark bbox: detector's region if confident, else the default config slot."""
|
||||
@@ -459,18 +478,8 @@ def cmd_erase(
|
||||
default=0,
|
||||
help="Cap long side (px) before diffusion; 0 = native (best quality, like raiw.cc). Raise only on GPU/MPS OOM.",
|
||||
)
|
||||
@click.option(
|
||||
"--no-protect-text",
|
||||
is_flag=True,
|
||||
default=False,
|
||||
help="Disable automatic text protection (text/CJK is preserved by default on the SDXL pipeline).",
|
||||
)
|
||||
@click.option(
|
||||
"--no-protect-faces",
|
||||
is_flag=True,
|
||||
default=False,
|
||||
help="Disable face protection (skips the YOLO face detector; use when the image has no people).",
|
||||
)
|
||||
@_protect_text_option
|
||||
@_protect_faces_option
|
||||
@click.pass_context
|
||||
def cmd_invisible(
|
||||
ctx: click.Context,
|
||||
@@ -484,8 +493,8 @@ def cmd_invisible(
|
||||
hf_token: str | None,
|
||||
humanize: float,
|
||||
max_resolution: int,
|
||||
no_protect_text: bool,
|
||||
no_protect_faces: bool,
|
||||
protect_text: bool,
|
||||
protect_faces: bool,
|
||||
) -> None:
|
||||
"""Remove invisible AI watermarks (SynthID, StableSignature, TreeRing).
|
||||
|
||||
@@ -531,8 +540,8 @@ def cmd_invisible(
|
||||
guidance_scale=None,
|
||||
seed=seed,
|
||||
humanize=humanize,
|
||||
protect_text=not no_protect_text,
|
||||
protect_faces=not no_protect_faces,
|
||||
protect_text=protect_text,
|
||||
protect_faces=protect_faces,
|
||||
max_resolution=max_resolution,
|
||||
)
|
||||
elapsed = time.monotonic() - t0
|
||||
@@ -707,18 +716,8 @@ def cmd_identify(ctx: click.Context, source: Path, no_visible: bool, as_json: bo
|
||||
default=0,
|
||||
help="Cap long side (px) before diffusion; 0 = native (best quality, like raiw.cc). Raise only on GPU/MPS OOM.",
|
||||
)
|
||||
@click.option(
|
||||
"--no-protect-text",
|
||||
is_flag=True,
|
||||
default=False,
|
||||
help="Disable automatic text protection (text/CJK is preserved by default on the SDXL pipeline).",
|
||||
)
|
||||
@click.option(
|
||||
"--no-protect-faces",
|
||||
is_flag=True,
|
||||
default=False,
|
||||
help="Disable face protection (skips the YOLO face detector; use when the image has no people).",
|
||||
)
|
||||
@_protect_text_option
|
||||
@_protect_faces_option
|
||||
@click.pass_context
|
||||
def cmd_all(
|
||||
ctx: click.Context,
|
||||
@@ -735,8 +734,8 @@ def cmd_all(
|
||||
hf_token: str | None,
|
||||
humanize: float,
|
||||
max_resolution: int,
|
||||
no_protect_text: bool,
|
||||
no_protect_faces: bool,
|
||||
protect_text: bool,
|
||||
protect_faces: bool,
|
||||
) -> None:
|
||||
"""Remove ALL watermarks: visible + invisible + metadata.
|
||||
|
||||
@@ -827,8 +826,8 @@ def cmd_all(
|
||||
num_inference_steps=steps,
|
||||
seed=seed,
|
||||
humanize=humanize,
|
||||
protect_text=not no_protect_text,
|
||||
protect_faces=not no_protect_faces,
|
||||
protect_text=protect_text,
|
||||
protect_faces=protect_faces,
|
||||
max_resolution=max_resolution,
|
||||
)
|
||||
console.print(" Invisible watermark removed")
|
||||
|
||||
@@ -125,8 +125,8 @@ class InvisibleEngine:
|
||||
guidance_scale: float | None = None,
|
||||
seed: int | None = None,
|
||||
humanize: float = 0.0,
|
||||
protect_faces: bool = True,
|
||||
protect_text: bool = True,
|
||||
protect_faces: bool = False,
|
||||
protect_text: bool = False,
|
||||
max_resolution: int = 0,
|
||||
) -> Path:
|
||||
"""Remove invisible watermark from an image.
|
||||
|
||||
Reference in New Issue
Block a user