A robust hybrid watermarking scheme based on DCT and SVD for copyright protection of stereo images

Digital watermarking is a technique that is widely used to protect rightful ownership of digital images. In this paper, we proposed a hybrid watermarking scheme for stereo images copyright protection. According to the property of stereo images, similar block pairs are located by using a certain key. Then, each block pair is transformed into DCT domain and DCT coefficients are extracted from the anti-diagonal of such block pair to form matrix A. Watermark image is embedded into singular values by applying SVD transformation on the matrix A. The experimental results showed that the proposed scheme can resist to different types of image attacks, such as salt and pepper, noise, and gaussian (density up to 5%). In addition the bit correlation ratio of extracted watermarked images is obtained up to 95%.