Digital Image Watermarking using a Highly Secure Novel Hybrid Algorithm

Proposed here is an image watermarking scheme useable for authentication and copyright protection. A hybrid scheme that combines the advantages of DWT and DCT is devised and implemented. Here the whole of host image is not subjected to forward and reverse transform operations as done usually, instead the hosting image pixels alone are subjected to the two ways transform operation. Hence while operating on larger sized images, it is faster and more efficient as other pixels not used are left intact and untampered. The algorithm proposed is tested on numerous standard test images and the results are noted down. Common attacks that rupture the hidden watermark are also tested, to which a good level of robustness is obtained as demonstrated by the test results. Keywords - watermark embedding; digital image watermark extraction; transform domain method; resiliance to attacks