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)

pip install Pillow numpy

Usage

# 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