A PVD-based data hiding method with histogram preserving using pixel pair matching

This paper proposed a Pixel Value Difference (PVD) based method to embed unequal amounts of secret information using pixel complexity. In previous PVD methods, embedding was sequential. Therefore, secret information can be easily accessed by a third party by the sequence. These methods are also easily detected by difference histogram analysis since their difference histograms showed unnatural shapes when compared to the cover image. The IMF-PVD method has a smoother and more natural difference histogram but its payload is not improved over the other PVD-based methods. In the proposed method, secret information was embedded in 2 x 2 embedding cells which were composed with randomized embedding units to reduce the falling-off-boundary problem and to eliminate sequential embedding. Comparison results with IMF-PVD showed that the proposed method significantly had higher payload and image quality. Furthermore, the payload size may be adjusted by reference tables and threshold. Results also showed that the embedded information is not easily detected by the difference histogram analysis and chi-square test. (C) 2014 Elsevier B.V. All rights reserved.