Digital watermarking technique for protecting digital images

Internet evolution, along with the advancement of digital multimedia tools have create a major impact in making the storage and distribution of multimedia content a straightforward tasks. Thus security of multimedia contents becomes a vital issue and there is a need in protecting the digital content against counterfeiting, piracy and malicious manipulations. Digital watermarking is an evolving field that requires continuous effort to find for the best possible method in protecting multimedia content. In this paper, we describe overview of digital image watermarking technique and proposed an algorithm for copy write protection of digital images in DCT domain. Digital watermarking can be defined as the process of embedding a certain piece of information, technically known as watermark into multimedia content including text documents, images, audio or video streams, such that the watermark can detected or extracted later to make an assertion about the data. We have also implemented this algorithm using MATLAB 7.x and code is also given in this paper.