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Gemini Watermark

Remove visible Gemini AI watermarks from images via reverse alpha blending. Use for cleaning Gemini-generated images, removing the star/sparkle logo watermar...

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Remove visible Gemini AI watermarks from images via reverse alpha blending. Use for cleaning Gemini-generated images, removing the star/sparkle logo watermar...

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Install for OpenClaw

Quick setup
  1. Download the package from Yavira.
  2. Extract the archive and review SKILL.md first.
  3. Import or place the package into your OpenClaw setup.

Requirements

Target platform
OpenClaw
Install method
Manual import
Extraction
Extract archive
Prerequisites
OpenClaw
Primary doc
SKILL.md

Package facts

Download mode
Yavira redirect
Package format
ZIP package
Source platform
Tencent SkillHub
What's included
SKILL.md, references/algorithm.md, scripts/remove_watermark.py

Validation

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  • Review SKILL.md after the package is downloaded.
  • Confirm the extracted package contains the expected setup assets.

Install with your agent

Agent handoff

Hand the extracted package to your coding agent with a concrete install brief instead of figuring it out manually.

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  2. Extract it into a folder your agent can access.
  3. Paste one of the prompts below and point your agent at the extracted folder.
New install

I downloaded a skill package from Yavira. Read SKILL.md from the extracted folder and install it by following the included instructions. Tell me what you changed and call out any manual steps you could not complete.

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I downloaded an updated skill package from Yavira. Read SKILL.md from the extracted folder, compare it with my current installation, and upgrade it while preserving any custom configuration unless the package docs explicitly say otherwise. Summarize what changed and any follow-up checks I should run.

Trust & source

Release facts

Source
Tencent SkillHub
Verification
Indexed source record
Version
2.1.0

Documentation

ClawHub primary doc Primary doc: SKILL.md 16 sections Open source page

Gemini Watermark Remover

Remove the visible Gemini AI watermark (star/sparkle logo) from generated images using mathematically accurate reverse alpha blending. Fully offline β€” pure Python, no external binary downloads, no network access.

When to Use

Remove the Gemini watermark from AI-generated images Batch process a directory of Gemini-generated images Clean images before publishing or sharing Automate watermark removal in pipelines

Install Dependencies (one-time)

pip install Pillow numpy # Recommended: use uv for faster, isolated installs uv pip install Pillow numpy Requires: Python β‰₯ 3.9. No Rust toolchain, no compiled binaries, no downloads.

Basic Usage

# Single image (auto-detect watermark, save as photo_cleaned.jpg) python3 scripts/remove_watermark.py photo.jpg # Specify output path python3 scripts/remove_watermark.py photo.jpg -o clean_photo.jpg # Batch process directory python3 scripts/remove_watermark.py ./input_dir -o ./output_dir # Force removal without detection python3 scripts/remove_watermark.py photo.jpg -o clean.jpg --force

How It Works

Gemini adds a semi-transparent white star/sparkle logo to generated images using alpha blending: watermarked = alpha * 255 + (1 - alpha) * original This tool reverses the equation to recover the original pixels: original = (watermarked - alpha * 255) / (1 - alpha) The alpha map (watermark transparency pattern) is generated mathematically as a 4-pointed star (central Gaussian core + 4 elongated cardinal rays) at two sizes: 48Γ—48 with 32 px margin β€” images where either dimension ≀ 1024 px 96Γ—96 with 64 px margin β€” images where both dimensions > 1024 px For improved accuracy you can supply your own alpha map derived from a background capture of the Gemini watermark on a white background (--alpha-map).

Detection

Before removal, a three-stage algorithm checks whether a watermark is present: Spatial NCC (50% weight) β€” normalised cross-correlation with the alpha map Gradient NCC (30% weight) β€” edge signature matching via Sobel operators Variance Analysis (20% weight) β€” texture dampening detection Images without detected watermarks are automatically skipped.

CLI Parameters

ParameterShortDefaultDescriptioninput(required)Input image file or directory--output-o{name}_cleaned.{ext}Output file or directory--force-ffalseSkip detection, process unconditionally--threshold-t0.35Detection confidence threshold (0.0–1.0)--force-smallfalseForce 48Γ—48 watermark size--force-largefalseForce 96Γ—96 watermark size--alpha-map(built-in)Custom grayscale alpha map image--verbose-vfalseEnable detailed output--quiet-qfalseSuppress all non-error output

Supported Formats

FormatReadWriteJPEG (.jpg, .jpeg)YesYes (quality 100)PNG (.png)YesYesWebP (.webp)YesYesBMP (.bmp)YesYes

Usage Examples

# Verbose output (shows detection confidence, watermark coordinates) python3 scripts/remove_watermark.py photo.png -o clean.png -v # Lower detection threshold (more sensitive) python3 scripts/remove_watermark.py photo.jpg -t 0.15 # Force large watermark size regardless of image dimensions python3 scripts/remove_watermark.py photo.jpg --force-large -o clean.jpg # Batch process, quiet mode python3 scripts/remove_watermark.py ./gemini_images/ -o ./cleaned/ -q # Supply a custom alpha map for higher accuracy python3 scripts/remove_watermark.py photo.jpg --alpha-map my_alpha.png

Deriving a Custom Alpha Map

For pixel-perfect removal, capture the Gemini watermark on a pure white background and compute: alpha(x, y) = max(R, G, B) / 255 Save the result as a grayscale PNG and pass it via --alpha-map.

Output

Single file β€” saves to -o path, or {name}_cleaned.{ext} by default Directory β€” saves all processed images to the output directory Skipped images β€” images without detected watermarks are not modified (unless --force) Exit code β€” 0 on success, 1 if any image fails

"No watermark detected" on a watermarked image

Try lowering the threshold: -t 0.1 Or bypass detection entirely: --force Consider supplying a custom alpha map for your watermark variant

Image looks distorted after removal

The image may not have a Gemini watermark. Use detection (avoid --force) Try --force-small or --force-large to match the correct size Supply a custom alpha map for better precision

"Image too small" warning

The image dimensions are smaller than the watermark region. This typically means the image does not have a Gemini watermark.

ModuleNotFoundError: Pillow or numpy

pip install Pillow numpy # or uv pip install Pillow numpy

Limitations

Visible watermark only β€” this tool removes the visible star/sparkle logo watermark Cannot remove SynthID β€” Google's invisible watermark (SynthID) is embedded at the pixel level during generation and cannot be reversed Fixed position only β€” handles watermarks in the standard bottom-right position only Built-in alpha map is approximate β€” use --alpha-map with a captured reference for exact results

Category context

Agent frameworks, memory systems, reasoning layers, and model-native orchestration.

Source: Tencent SkillHub

Largest current source with strong distribution and engagement signals.

Package contents

Included in package
2 Docs1 Scripts
  • SKILL.md Primary doc
  • references/algorithm.md Docs
  • scripts/remove_watermark.py Scripts