US Patent 7770116 System and method for whiteboard and audio capture

A system that captures both whiteboard content and audio signals of a meeting using a digital camera and a microphone. The system can be retrofit to any existing whiteboard. It computes the time stamps of pen strokes on the whiteboard by analyzing the sequence of captured snapshots. It also automatically produces a set of key frames representing all the written content on the whiteboard before each erasure. The whiteboard content serves as a visual index to efficiently browse the audio meeting. The system not only captures the whiteboard content, but also helps the users to view and manage the captured meeting content efficiently and securely.