Gemini Watermark Remover (also known as Banana Remove) is a lightweight web application designed to automatically detect and remove the specific watermarks found on images generated by Google's Gemini models.
Unlike other tools that rely on heavy server-side processing or diffusion models, this project runs 100% in the browser. It utilizes a ported WatermarkEngine that performs reverse alpha blending using pre-calculated alpha maps to mathematically subtract the watermark without destroying the underlying pixel data.
The core logic resides in js/watermark-remover.js. The removal process follows these steps:
- Alpha Map Generation: The engine loads reference background patterns to calculate the precise alpha channel values of the watermark.
- Reverse Blending: It iterates through the pixels in the watermark's bounding box.
- Restoration: Using the formula
original = (watermarked - alpha * LOGO_VALUE) / (1 - alpha), it restores the original pixel color values that were obscured by the semi-transparent watermark.
This project builds upon the research and logic provided by the open-source community:
- GeminiWatermarkTool by Allen K - Special thanks for the original logic on watermark detection and reverse alpha blending.