Sine-wave-based text watermark for WORD document

In this paper, a digital watermark algorithm is proposed for the protection of WORD documents, based on a detailed analysis of WORD operators with reference to page description. The watermark, with the modification of the color of character font in the text, can be embedded into the document. After the modification, the font colors of various characters show the characteristics of a sine wave. The authenticity of a WORD document can be verified by distill the characteristics of font color and reconstruct the sine wave. Our experiments show that the watermarked documents have good perceptual transparence and the character changes in the WORD documents can be detected.