✨ GemClean — Gemini Watermark Remover 🧹

GemClean is an ultra-fast, privacy-first browser tool that erases visible watermarks from AI-generated images — entirely on your device. No uploads, no servers, no compromises. It leverages a precise Reverse Alpha Blending algorithm to mathematically restore original pixels with zero quality degradation.

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🔍 Overview

AI image generators like Google Gemini embed a small sparkle logo into every exported image. GemClean reverses the blending math to recover the clean, original pixels — all within milliseconds, right inside your browser tab.

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🚀 Key Features

Feature	Detail
Offline & Private	Zero network requests. Every pixel stays on your machine.
Mathematically Lossless	Exact inverse-blend formula — no AI guesswork, no quality loss.
Instant Processing	Sub-second results even on large 4K images.
Auto Size Detection	Automatically picks the correct 48 px or 96 px alpha map.
Batch Support	Drop multiple files at once; download them all as a ZIP.
Dark / Light Mode	Respects your system theme or toggle manually.
Zero Build Step	Pure ES6 modules + Tailwind CDN. Clone → serve → done.

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🧮 Algorithm Deep-Dive

🖼️ Step 1 — How the watermark is applied

The AI renderer composites a semi-transparent white logo on top of the original image using standard alpha blending:

$$C_{out} = \alpha \cdot C_{logo} + (1 - \alpha) \cdot C_{src}$$

Symbol	Meaning
$\alpha$	Per-pixel opacity of the watermark (0 → 1)
$C_{logo}$	Watermark colour — pure white (255)
$C_{src}$	The original pixel we want back
$C_{out}$	The watermarked pixel you downloaded

🔄 Step 2 — Reversing the math

We know $C_{out}$, $C_{logo}$, and the full $\alpha$ map (extracted once from reference captures). Solving for $C_{src}$:

$$C_{src} = \frac{C_{out} - \alpha \cdot C_{logo}}{1 - \alpha}$$

The result is clamped to [0, 255] and rounded to the nearest integer.

🗺️ Step 3 — Alpha map extraction

Two reference PNGs (bg_48.png, bg_96.png) capture the isolated watermark at both supported sizes. On first load, each reference is drawn to an off-screen canvas and its max channel value per pixel is normalised into a Float32Array — giving us a per-pixel opacity map accurate to floating-point precision.

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📁 Repository Layout

GeminiLogoRemover/
├── assets/
│   ├── bg_48.png          # Alpha reference — small images (≤ 1024 px)
│   └── bg_96.png          # Alpha reference — large images (> 1024 × 1024 px)
├── js/
│   ├── alphaMap.js        # Builds the Float32 opacity map from a reference PNG
│   ├── blendModes.js      # Reverse alpha-blend formula implementation
│   ├── engine.js          # Orchestrator — loads assets, runs pipeline
│   └── app.js             # DOM bindings, drag-and-drop, download logic
└── index.html             # Single-page application entry point

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🛠️ Tech Stack

Layer	Choice
Markup	Semantic HTML5
Styling	Tailwind CSS via CDN — zero build config
Logic	Vanilla ES6+ modules — no React, no Vue, no bundler
Icons	Iconify (on-demand SVG delivery)
Archiving	JSZip for multi-file downloads

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⚡ Quick Start

Note: ES6 module imports require a local HTTP server — opening index.html via file:// will fail due to CORS.

VS Code (recommended)

1. Install the Live Server extension.
2. Right-click index.html → Open with Live Server.

Python one-liner

python -m http.server 8080

Node one-liner

npx serve .

Then open http://localhost:8080 in any modern browser.

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⚠️ Disclaimer

This project is intended for educational and personal use only.

• It removes the visible sparkle logo only; it does not strip the invisible SynthID metadata embedded by Google.
• Always respect the Terms of Service and intellectual-property rights of the original image generator.

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👤 Author & Credits

Developed & maintained by LittleFox

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© 2026 LittleFox. Released under the MIT License.