Digital Watermarking for the Protection of Music Scores

The need for protection mechanisms for multimedia content is widely recognized. In the past digital watermarking algorithms for images have been developed that provide a certain level of protection for colored or gray-scale images. Since classical raster-oriented watermarking algorithms do not satisfy the needs for symbol oriented music score images we present in this paper a solution that should give promising robustness of the watermark at minimal visibility impact. This solution respects the content of binary images and can be considered as a symbolic interpretation and modification of music scores. Some music symbols are used by changing their features for hiding an information string in a music score. The advantage is its robustness and invisibility. Regarding the invisibility a musician should under no circumstances be impeded in reading the music. One must even consider the fact of being influenced unconsciously. For example, it might be more difficult to concentrate on a music sheet if the symbols were changed invisibly. The most probable way of distributing music scores is the analog (paper) form. Music scores are copied and distributed. So watermarks should be readable even after multiple copy procedures. By choosing suitable features a blind detection of the watermark is possible.