A Reversible Information Hiding Algorithm for 2D Vector Maps

Vector maps have been heavily utilized in many geographic information system (GIS) applications. In such applications, the precision of data is a critical issue. Hence, as we developed a 2D vector map information hiding algorithm, in addition to the embedding capacity, the reversible mechanism and the distortion of the recovery maps were very important factors in our considerations. This paper proposes a reversible, high capacity, and very low distortion information hiding algorithm for 2D vector maps. Our algorithm performs with the embedding capacity of 2(n-2) bits, where n represents the number of vertices in the cover vector map. To the best of our knowledge, this is the highest capacity in the liteature of information hiding for vector maps so far. Our scheme produces a stego vector map with what we believe is the lowest distortion achieved to date, only 0.000012 of the root mean square error. Once the secret message is extracted, our method provides the capacity to leave the map in a recovered form that is a virtual reproduction of the original vector map. The original and the recovered maps have insignificantly small differences, less than 4.79E-09 of the root mean square error, a level imperceptible to the human visual system. Our algorithm belongs to the scheme of blind detection, where the secret message can be extracted without referring to the original cover vector map. The proposed algorithm is also secure and robust against affine transformation. We conclude that our algorithm provides a feasible solution for 2D vector map information hiding with reversibility and very low distortion.