Date Added: Nov 2010
Due to improvement in imaging technology and the ease with which digital content can be reproduced and manipulated there is a strong need for a digital copyright mechanism to be put in place. There is a need for authentication of the content as well as the owner. It has become easier for malicious parties to make scalable copies of copyrighted content with any compensation to the content owner. Digital Watermarking is being seen as a potential solution to this problem. Till date many different watermarking schemes have been proposed. This paper presents a comprehensive survey of the current techniques that have been developed and their effectiveness.