A Text Digital Watermarking for Chinese Word Document

More and more enterprises, organisations and governments have used and disturbed information in word documents, pdf etc. It makes easily to unauthorized copying and dissemination. According to DRM¿s requirements that are high performance and feasible, we evaluated two common text watermarking methods for instructing practical applications, and proposed a new approach in text watermarking where inter-character spaces are slightly modified for coding. The capacity is improved to 1/3 bit per Chinese character. It is efficient extracting watermarking from document or screen-capture-image. Our experiments suggest it is suitable for word documents and chinese language.