Hadamard transform based adaptive visible/invisible watermarking scheme for digital images

In this work, a novel and adaptive visible/invisible watermarking scheme for embedding and extracting a digital watermark into/from an image is proposed. The proposed method uses an adaptive procedure for calculating scaling factor or scaling strength using sigmoid function in Hadamard transform domain. The value of scaling factor is governed by a control parameter. The control parameter can be adjusted to make the watermarking scheme as either visible or invisible. The proposed methodology facilitates in preserving ownership rights and prevents the piracy of digital data which are considered to be the basic needs of digital watermarking. As proposed watermarking process is carried out in Hadamard transform domain, it is more robust to image/signal processing attacks. The experimental results and performance analysis confirm the efficiency of the proposed scheme.