Zero-watermarking algorithm using edge enhancing
Jingping Liu · Journal of Computer Applications · 2012
Robustness and invisibility are two important characteristics of watermarking.To meet these requirements,a new zero-watermarking algorithm based on Singular Value Decompositon(SVD) and gradient was proposed in this paper.Firstly,do block-SVD transform on the host image.Then select the largest singular value of each block.After that a small scale image which is similar to the host image will be obtained.Secondly calculate the small scale image's gradient modulus,and divide these data into two parts using the following rules: if the value is greater than the mean,the result is 1;or is 0.The consequence is the image's characteristic information.Finally do XOR operation on the characteristic data and the watermark data.When detecting the watermark,the result of XOR operation will be used as the key.The experimental results show that this approach has good performance to the filtering,sharpening,histogram equalization,JPEG compression and crop.