Gemini Watermark Remover

# Gemini Watermark Remover

Remove visible Gemini AI watermarks (star/sparkle logo) from generated images using mathematically accurate reverse alpha blending.

Fully offline — pure Python, local processing only, images are not uploaded.

When to Use

• Remove watermark from Gemini AI generated images
• Clean images before publishing or sharing
• Batch process multiple images

Quick Start

Install Dependencies (one-time)

```bash pip install Pillow numpy ```

Usage

```bash # Single image (auto-detect watermark) python3 scripts/remove_watermark.py photo.jpg

# Specify output path python3 scripts/remove_watermark.py photo.jpg -o clean_photo.jpg

# Force removal without detection python3 scripts/remove_watermark.py photo.jpg -o clean.jpg --force ```

How It Works

Gemini adds watermark using alpha blending:

``` watermarked = alpha * 255 + (1 - alpha) * original ```

Reverse the equation:

``` original = (watermarked - alpha * 255) / (1 - alpha) ```

Detection Rules

| Image Size | Watermark Size | Right Margin | Bottom Margin | |------------|---------------|--------------|---------------| | Width > 1024 AND Height > 1024 | 96×96 | 64px | 64px | | Otherwise | 48×48 | 32px | 32px |

Key Points

• Uses built-in watermark templates (`assets/bg_48.png` / `assets/bg_96.png`)
• Alpha map = max RGB channel value (not alpha channel)
• Includes noise filtering (ALPHA_NOISE_FLOOR)
• Pure mathematical method, pixel-level accuracy

Limitations

• Removes only visible watermark (bottom-right semi-transparent logo)
• Cannot remove invisible watermarks (e.g., SynthID)
• Designed for current Gemini watermark pattern

Dependencies

• Python 3
• Pillow (PIL)
• NumPy