Combined just noticeable difference model guided image watermarking

Perceptual Watermarking should take full advantage of the results from human visual system (HVS) studies. Just noticeable difference (JND), which refers to the maximum difference that the HVS does not perceive, gives us a way to model the HVS accurately. In this paper, we exploit a combined JND model which represents additional accurate perceptual visibility threshold profile to guide watermarking for digital images. The proposed combined JND model guided watermarking scheme, where visual models are fully used to determine image dependent upper bounds on watermark insertion, allows us to provide the maximum strength transparent watermark. Experimental results confirm the improved performance of our combined JND model. Our combined JND model is capable of yielding higher injected-watermark energy without introducing noticeable difference to the original image and outperforms the relevant existing visual models. Robustness results show the proposed JND model guided watermarking scheme performs much better than other algorithms based on Watson´s perceptual model.