Digital watermarking: An approach based on Hilbert transform

Most of the well known algorithms for watermarking of digital images involve transformation of the image data to Fourier or singular vector space. In this paper, we introduce watermarking in Hilbert transform domain for digital media. Hilbert transform provides an analytic representation of a signal in terms of a phase and amplitude function. In this work, we apply one-dimensional Hilbert transform on each of the vectors that define an image and embed the watermark in its phase. Based on this idea, we propose an algorithm for embedding and extracting watermark in a host image and analytically obtain a parameter related to this procedure. Using extensive simulations, we show that the algorithm performs well even if the host image is corrupted by various attacks.