Improved PVO-based reversible data hiding: A new implementation based on multiple histograms modification

• An improved pixel-value-ordering (PVO) based reversible data hiding based on multiple histograms modification (MHM) is proposed.
• The new algorithm is considered in a framework that is based on MHM and parameterized by the selection of expansion bins.
• The proposed MHM determination is a methodology of adaptive histogram modification, and is applicable for the existing techniques of histogram generation.

Pixel-value-ordering (PVO) technique is based on ranking the pixels within a block and often employed in reversible data hiding (RDH) to preserve the image fidelity. In this paper, an improved PVO-based algorithm is proposed to achieve a high-performance RDH. We formulate the PVO embedding as a problem of multiple histograms modification (MHM) and make two contributions. Firstly, the existing PVO-based algorithms are generalized in an MHM form and the systematic analysis of performance is offered by considering the parameter determination. Secondly, based on the new framework, an improved implementation of PVO embedding is proposed to adaptively determine the MHM manner by solving the distortion minimization of multiple histograms, which can handle different characteristics in image areas. Experimental results show the superiority of the new algorithm over the state-of-the-art methods.