PlataJanus: an audio annotation watermarking framework

The focus of audio watermarking research in recent years have been copyright protection and copy control mechanisms. Therefore the robustness and security of audio watermarks have been the most frequently discussed parameters. Transparency, payload and complexity have also been important, but most research has focused on the first two parameters. In this paper, we introduce an alternative watermarking application. PlataJanus is a system for displaying and reacting on digital annotation watermarks. A watermark is embedded in an audio stream. When the audio data is accessed by a user, a detection mechanism is started. This mechanism interprets the format of the accessed media type. If a watermarking detector for this type is present, it is used to search for a message in the media. This message is then interpreted and depending on it various actions can be executed, from text display to web browser activation. We introduce the concept of annotation watermarking in section 1. In Section 2 we discuss a comparison with copyright watermarking and introduce the PlataJanus environment with its components for watermark detection and reaction in section 3. Furthermore possible applications for PlataJanus are presented.