Reversible q-ary watermarking with controllable prediction error and location map-free capability
Tatiana Efimushkina, Karen Egiazarian · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2012
In this paper a new q-ary reversible high-capacity lossless scheme with a controllable prediction error is presented. The proposed scheme holds the advantages of embedding of more than one bit per pixel in a single run of an algorithm due to the utilization of secret data from Galois field, and avoidance of the redundant data, by deriving the special conditions. The new histogram shifting approach was elaborated to achieve higher capacity versus quality of the image compared to introduced by authors1 data hiding counterpart based on difference expansion method. In order to reach high computation efficiency we introduce a new weighted simplified predictor. The comparison with the existing predictors in terms of computation efficiency and the amount of embedded payload is presented. Experimental part produces the comparison of the proposed scheme on different test images. The new technique is compared with a number of reversible methods, including our previous scheme1 based on difference expansion, where it produces the better embedding capacity versus image quality performance. We also demonstrate the behavior of the schemes for various q via data rate versus quality curves. The proposed scheme not only holds the advantages of the location map free data embedding, but also enables high payload capacity.