Digital Image Watermarking: Transform Domain Perspective

The rapid expansion of the internet in the past years has rapidly increased the availability of digital data such as audio, images and videos to the public. The problem of protecting multimedia information becomes more and more important and a lot of copyright owners are concerned about protecting any illegal duplication of their data or work. This is an interesting challenge and this is probably why so much attention has been drawn toward the development of digital information protection schemes.Of the many approaches possible to protect visual data, digital watermarking is probably the one that has received most interest. The idea of watermarking of images is to embed information data within the image with an insensible form for human visual system and the goal is to produce an image that looks exactly the same to a human eye but still allows its positive identification in comparison with the owner's key if necessary.