A NOVEL APPROACH FOR IMAGE WATERMARKING USING DCT AND JND TECHNIQUES

Today�s world is digital world. Nowadays,in every field there is enormous use of digital contents. Information handled on internet and multimedia netw ork system is in digital form. The copying of digital content without quality loss is not so diff icult. Due to this,there are more chances of copyi ng of such digital information. So,there is great need o f prohibiting such illegal copyright of digital med ia. Digital watermarking is the powerful solution to ad dress this problem. Digital watermarking is the technology in which there is embedding of various t ypes of information in digital content which we have to protect from illegal copying. This embedded information to protect the data is embedded as watermark. This paper introduces two novel techniqu es for image watermarking such as DCT and JND. The DCT based approach adapted to embed waterm arks in DC,low,mid and high frequency components coefficient of DCT. The JND based approa ch gives robust and transparent scheme of watermarking that exploits the �human visual system s� sensitivity to local image characteristics obtained from the spatial domain,improving upon th e content based image watermarking scheme. In JND method,we consider texture,luminance,corner and the edge information in the image to generate a JND (Just Noticeable Distortion) mask that makes the addition of the watermark less perceptible to the human eye. The process of embedding and extract ion of the watermark is done in the frequency domain for providing robustness. The image test dat a base includes (grey scale) host and watermark images of size 256*256 and the performance evaluati on metrics used are PSNR (Peak Signal to Noise Ratio) and correlation.

https://www.ijiert.org/paper-details?paper_id=140305