Perceptual watermarking should take full advantage of the results from human visual system (HVS) studies. Just noticeable distortion (JND), which refers to the maximum distortion that the HVS does not perceive, gives us a way to model the HVS accurately. In this paper, another very important aspect affecting human perception, visual saliency, is introduced to modulate JND profile. Based upon visual saliency's modulatory effect on JND profile which incorporates visual attention's influence on visual sensitivity, the saliency modulated JND model guided image watermarking scheme is proposed. Experimental results confirm the improved performance of our saliency modulated JND model. Our saliency modulated JND model is capable of shaping lower injected-watermark energy onto more sensitive regions and higher energy onto the less perceptually significant regions in the image, which yields better visual quality of the watermarked image. At the same time, the proposed saliency modulated JND model guided image watermarking scheme is more robust than unmodulated JND model guided image watermarking scheme while retaining the watermark transparency.
['Yaqing Niu', 'Qin Zhang', 'Matthew Kyan', 'Sridhar Krishnan']
A combined just noticeable distortion model guided image watermarking