High capacity reversible image watermarking based on integer transform

Many reversible watermarking algorithms have been proposed in the literature, and all of these solutions put emphasis on high embedding capacity with low distortion. In this paper, a novel reversible image watermarking method based on integer transform is presented. Through taking pixel block of arbitrary size as embedding unit, the method can provide a very high embedding capacity. For instance, it can embed as large as 1.85 bits per pixel in “Lena”. Besides, by pre-estimating the embedding distortion, one can suitably select embeddable blocks so that the visual quality of the watermarked image is well guaranteed. Furthermore, extensive experiments show that the novel method performs better than some state-of-the-art algorithms.