An Improved Watermarking Algorithm for Digital Images Based on DCT and SVD
Hua Jiang · Computer Engineering and Science · 2009
A novel watermarking algorithm for digital images based on DCT and SVD is proposed in this paper,which combines both the merits of discrete cosine transform(DCT) and singular value decomposition(SVD).The conflicts between transparency and robustness of the watermarking system is better solved by the algorithm.Firstly,we select some low frequency coefficients of the original image in a zig-zig order to create a matrix the same size as the watermarking images.Then,the digital watermarks are embedded by SVD.It not only increases the embedded information capacity but guarantees the safety of data.Experimental results show that the new watermarking scheme has good transparency,and is robust against attacks such as added noise,JPEG compression and geometric distortion.