Introduction to Open Video Watermark
Open Video Watermark is a production-ready web application and developer toolkit that embeds invisible, imperceptible watermarks into video files using frequency-domain Discrete Cosine Transform (DCT) algorithms.
Designed for content creators, media platforms, and digital rights enforcement, the embedded watermarks are imperceptible to the human eye while remaining recoverable even after compression, transcoding, and filtering.
🌟 Key Highlights
- 🔒 DCT Frequency-Domain Watermarking: Embeds watermarks in middle-frequency DCT coefficients of individual video frames.
- ⚡ Real-Time Progress with WebSockets: Frame-by-frame progress streaming using Flask-SocketIO.
- 🔄 Asynchronous Worker Queue: Non-blocking encoding via background thread workers.
- 🌐 Dual Interface: Full-featured Single Page Application (SPA) web UI plus a clean RESTful API.
- 🛡️ Hardened Security: Magic-byte MIME detection, extension allow-listing, OpenCV frame verification, rate limiting, and strict CSP headers.
- 🐳 Container Ready: Complete
Dockerfileanddocker-compose.ymlwith Nginx reverse proxy configurations.
🎯 How It Works: DCT Frequency Domain
Unlike traditional spatial watermarking (which modifies raw pixel values and is easily destroyed or noticed), DCT frequency-domain watermarking operates in the transformed frequency domain:
- Frame Extraction: Each frame of the input video is extracted and converted to the YUV or YCrCb color space.
- Block Partitioning: The luminance (Y) channel is divided into $8 \times 8$ pixel blocks.
- Discrete Cosine Transform: Each $8 \times 8$ block is transformed into 64 orthogonal frequency coefficients.
- Mid-Frequency Embedding: The watermark bit sequence is embedded into selected mid-frequency coefficients, balancing perceptual invisibility with robustness against lossy video compression (e.g. H.264 / AVC).
- Inverse DCT (IDCT): The spatial frame is reconstructed via IDCT and reassembled into the video stream.
🚀 Getting Started
To get started right away:
- Follow the Installation Guide for Docker or manual setup.
- Explore the API Reference to automate watermarking in your pipeline.
- Read the Changelog for the latest release notes.