A novel approach on transform domain watermarking against geometrical deformations

Most of the methods involved in transform domain watermarking perform very well in a great variety of attacks but fail miserably in the category of the attacks known as geometrical. Usually, even a small rotation or slight zoom in/out of the watermarked image, results to detection failure. These attacks can be modelled by means of the affine transform. There are some suggestions that cope with this problem and an overview of them is presented in this communication, along with a new improved solution to this.