Improved Reversible Image Authentication Scheme

Image integrity authentication has aroused concerns because of the frequent modification on images. However, most of the image authentication schemes proposed so far employed the irreversible data hiding approach and the results of the published few reversible authentication methods are not satisfactory. To improve the detection accuracy as well as marked image quality, this paper proposes an improved reversible image authentication method based on Hilbert Curve mapping. In the proposed method, pixels are first mapped to a one-dimensional vector by using Hilbert Curve and divided into non-overlapping sets. Then, authentication codes can be embedded into each set by reversible data hiding approach. After comparing the extracted bits with the original authentication codes, the image set could be taken as modified one or unmodified one. Because image redundancy can be explored more fully and more flexibly by adopting Hilbert Curve mapping, more authentication codes can be embedded into the host image while leaving less distortion. Thus, both the detection accuracy and the marked image quality can be improved. The experimental results demonstrate the improvement compared with the latest development of reversible image authentication.