A hybrid intelligent SVD-based perceptual shaping of a digital image watermark in DCT and DWT domain

In this paper, an intelligent hybrid watermarking algorithm for digital images has been proposed. In digital image watermarking, robustness and imperceptibility compete with each other. In this research, we applied a DCT-DWT-SVD-based intelligent algorithm to make a trade off between these two functions. The algorithm initially transforms the original image into DCT domain and then it decomposes a part of DCT matrix into four sub-bands using discrete wavelet transform, then the singular values of each sub-band are shaped perceptually by singular values of watermark image to embed the watermark. In order to achieve the best performance in robustness without losing the quality of host image, the optimisation problem which is related to a conflict between robustness and imperceptibility is solved by means of genetic programming and particle swarm optimisation simultaneously. Experimental results show improvement in imperceptibility and robustness under several attacks and different images.