Novel Scheme of Reversible Watermarking With a Complementary Embedding Strategy

In this paper, a new scheme of reversible watermarking is proposed using a complementary embedding strategy in the spatial domain. The proposed scheme consists of two stages: horizontal direction embedding and vertical direction embedding. A complementary embedding strategy is designed to increase the embedding capacity and decrease the distortion of the watermarked image in the vertical direction embedding. Specifically, in the horizontal direction, the proposed scheme embeds one secret data bit by increasing values of pixels in even rows and decreasing values of pixels in odd rows by one. In the vertical direction, it embeds another secret data bit by decreasing values of pixels in even rows and increasing values of pixels in odd rows by one. In addition, a histogram shrinkage technique is adopted to prevent overflow and underflow problems. Experimental results demonstrate that the proposed reversible watermarking scheme outperforms state-of-the-art methods in terms of both embedding capacity and watermarked image quality.