An efficient DCT based image watermarking scheme for protecting distribution rights

The chances of copyright violation and piracy have been increased due to growth of networking and technology. Digital watermark is useful to verify the integrity of the content and for authenticity of an owner. The digital watermark must be robust against various attacks in order to protect the copyright information which is embedded in the original content. The proposed algorithm is useful for protecting the distribution rights of digital images. Watermark is embedded in the DCT coefficients of the host image and the watermark is pseudo randomly spread over the entire image using Linear Feedback Shift Register (LFSR). The algorithm shows improvement over existing algorithms in terms of Normalized Correlation (NC), Tamper Assessment Function (TAF) and Peak Signal to Noise ratio (PSNR). The proposed algorithm outperforms the related previous work with better results.