Robust Image Watermarking Technique to Increase Security and Capacity of Watermark Data.

Abstract

The recent progress in the digital multimedia technologies has offered many facilities in the transmission, reproduction and manipulation of data. However, this advancement has also brought the challenge such as copyright protection for content providers. Digital watermarking is one of the proposed solutions for copyright protection of multimedia data. This technique is better than Digital Signatures and other methods because it does not increase overhead. Digital watermarking is not a very old field. Most of research is going on in this field. Researchers try to invent techniques that increase the security, capacity, and imperceptibility of watermarked images In this thesis we presented a new image watermarking technique that can embed more number of watermark bits in the cover image without affecting the imperceptibility and increase the security of watermarks. To increase the embedding capacity the concept of watermark in watermark is used. Means it embeds an extra watermark into the main watermark and then embeds the main watermark into the cover image. To increase security we embed encrypted watermarks in the image. This provides an additional level of security for watermarks. For instance if watermarking key is hacked still the attacker will not be able to identify the watermark because it is encrypted.