Design And Implement Of Cloud Model Text Digital Watermarking Algorithm Based On The Color Of The Font

The research of the text digital watermarking is a cross research field. It involves researches on cryptography,Chinese information processing, image processing, graphics, vision science, communication and information security, etc and is a very new research direction. The present algorithms of text digital watermarking generally have the deficiency of little watermarking capacity and weak robustness. We therefore must study and carry out the new methods in robustness of watermarking.This paper puts forward the embedded watermarking method based on the color of the letter, which offsets the deficiency of the watermarking capacity and makes the protected text embedd much more watermarking information. This method utilizes the large amount of redundant spaces according to the different sensitivity of human eyes to color, and changes slightly the color percentage of less-sensitivity which is impossible for human eyes to discern. This method has good concealment and large watermarking capacity.This paper combines watermarking-embedding methods based on the colors of the letters with the Cloud Model Theory. The text copyrights are protected by embedding the text with watermarking cloud droplets. Cloud Model is the qualitative and quantitative interchangeable model based on the fuzzy mathematics and probability statistics.The number of cloud droplets representing qualitative conception is uncertain, and that of text letters needed copyright protection too. The Embedded cloud droplets represent certain qualitative conception of the cloud.Specially aiming at the three indexes: invisibility, robustness, and capacity, the author has carried out a great number of experiments, including embedding,extracting, and attacking the watermark, which use the watermarking software that based on VC and Matlab. The new digital watermarking algorithm is verified that it has excellent invisibility, strong robustness, and large capacity. A watermarking system program on VC platform was designed and implemented. Some key problems were solved during the programming.The research result in this paper deals with the problems of the small-capacity, weak robustness of the present text digital watermarking algorithms, which can adapt to text of any size to protect copyright, and has some impact on both theory and practice of the watermarking technology.