SVD Based Digital Watermarking Algorithm for Print-And-San Process

Analysing the effect of scanning process on the image. This paper proposes a watermarking algorithm based on DWT and SVD. With the features of printing and scanning, the algorithm firstly decomposes a image by discrete wavelet transform for first order, then carries on singular value decomposition in the low-frequency subgraph, and then embeds watermark sequence in the singular value, and corrects distortion before watermarking extraction. Experiments show that this algorithm is robust for printing and scanning and determine the second copy.