Image zero watermarking scheme based on DWT SVD 

In this paper, a novel copyright protection zero-watermarking scheme that combines the discrete wavelet transform (DWT) and the singular value decomposition (SVD) is proposed. Instead of modifying the original image data, which inevitably causes some permanent quality degradation, to embed a watermarking, the proposed scheme constructs a watermarkingfrom the image features which extracts from the original image by applying the DWT and the SVD. Firstly, the original image is decomposed into the appropriate levels by the DWT, and the obtained approximation image is divided into non-overlapping blocks.

The SVD is then applied to the each block to obtain the singular values. Finally, the embedding of zero-watermarking is realized through the exclusive or (XOR) operation between the first singular value of the each block and the pixel value of the actual binary character watermarking sequentially. The simulation results demonstrate that the proposed zero-watermarking scheme not only ensures the watermarked image quality without any distortion, but also has very good robustness to resist the common image processing attacks such as noise addition, filtering, compression and geometric cutting.