Dual secured hybrid image watermarking in wavelet and singular domain

These days there is an increased risk of copyright violation of multimedia data that has become an important issue for content owners and service providers. Watermarking technology aims at asserting Intellectual Property Rights (IPR) of digital images by inserting a copyright identifier in the contents of the image, to achieve copyright protection. The dual scrambled watermark is embedded on the elements of singular values of the scrambled cover image´s DWT middle frequency sub-band and the image scrambling is done by Arnold and Scrambling Sequence. The security levels are increased by using a key value and scaling factor for the embedding and extraction process. Various standard database gray scale images of size 512×512 and watermark of size 64×64 have been used and the simulation was performed on MATLAB 7.7.0. The correlation factor for Salt and pepper noise, Gaussian noise, JPEG compression, Gaussian low pass filter and Cutting methods used by Rui-mei et al. and Wang et al. were compared with proposed method using hybrid dual scrambled watermark scheme. The proposed method enhanced the robustness and imperceptibility of digital images.