Digital watermarking :
Any one using digital images (or even audio and video) know that it is difficult to secure them from unauthorised use. Digital watermarking is the technique by which visible or invisible message or logo can be implanted in digital media so that any unauthorised use can be detected at a later time. We have proposed a watermarking algorithm based on singular value decomposition in the eigenvector domain. We are interested in novel watermarking methods based on Hilbert transforms since that allows far more freedom to implant data in digital formats.
For an overview of digital watermarking, see Digital Watermarking World.
My paper on digital watermarking is available from