Minimizing Embedding Distortion with Weighted Bigraph Matching in Reversible Data Hiding
This work addresses the challenge of minimizing distortion in RDH for practical applications like secure image communication, though it is incremental as it builds on existing RDH methods by introducing a new optimization model.
The paper tackles the problem of reducing embedding distortion in reversible data hiding (RDH) by modeling the embedding operation as a weighted bipartite graph matching problem, specifically minimum weight maximum matching (MWMM), which finds an optimal histogram shifting strategy. Experimental results show that this method significantly improves payload-distortion performance when incorporated into existing RDH schemes.
For a required payload, the existing reversible data hiding (RDH) methods always expect to reduce the embedding distortion as much as possible, such as by utilizing a well-designed predictor, taking into account the carrier-content characteristics, and/or improving modification efficiency etc. However, due to the diversity of natural images, it is actually very hard to accurately model the statistical characteristics of natural images, which has limited the practical use of traditional RDH methods that rely heavily on the content characteristics. Based on this perspective, instead of directly exploiting the content characteristics, in this paper, we model the embedding operation on a weighted bipartite graph to reduce the introduced distortion due to data embedding, which is proved to be equivalent to a graph problem called as \emph{minimum weight maximum matching (MWMM)}. By solving the MWMM problem, we can find the optimal histogram shifting strategy under the given condition. Since the proposed method is essentially a general embedding model for the RDH, it can be utilized for designing an RDH scheme. In our experiments, we incorporate the proposed method into some related works, and, our experimental results have shown that the proposed method can significantly improve the payload-distortion performance, indicating that the proposed method could be desirable and promising for practical use and the design of RDH schemes.