ABSTRACT
This chapter deals with various theoretical aspects of watermarking which are necessary to understand before developing any new watermarking approach. It describes the basics of watermarking, different applications of watermarking, and various properties of watermarking. The chapter identifies different categories of watermarking based on features and different measures of watermarking. Digital watermarking is a strong substitute for the cryptography for the protection of digital content. It modifies the content in such a way that even after many normal modifications like rotation. The cover image, watermark, sender and receiver are the main components of a watermarking approach. By using a watermarking approach, one can prove ownership of any digital image. The sender must register the image with the copyright office or any trusted third party. A watermark can be used to verify the authenticity of a given cover image.
