A robust reversible image watermarking scheme in DCT domain using Arnold scrambling and histogram modification

Among the various watermarking schemes, the reversible watermarking scheme has drawn extensive attention in the recent years for its application in sensitive issues like medical, military and typical law-enforcement images. Cover image dependent embedding capacity and lack of robustness are the most crucial concerns of the reversible watermarking methods. To overcome these issues, a discrete cosine transform (DCT) and histogram shifting based robust reversible image watermarking scheme using Arnold scrambling is presented in this paper. Initially, the image is decomposed into non-overlapping blocks and consequently DCT are applied to each block to embed a binary bit of watermark into each transformed block by modifying one pair of middle significant AC coefficients. In this initial step, location map is also generated for the cover image restoration purpose in the extracting side. Then, this location map is embedded in the cover image using histogram modification technique. In the receiver side, at first location map is generated from an image using histogram modification method and watermark is recovered from the corresponding image. Using location map reversible image is reversed in the following extracting phase of the proposed method. The proposed reversible watermarking scheme has also been experimented to verify the robustness property against several image processing attacks and satisfactory results are achieved.