High-fidelity reversible data hiding based on pixel-value-ordering and pairwise prediction-error expansion

• This paper discusses the PVO embedding in two-dimensional (2D) space by integrating the pairwise prediction-error expansion, and a new 2D mapping adapted to the special distribution of pairs is proposed.
• An adaptive 2D mapping selection mechanism is proposed to treat the rough and smooth pairs differently to further optimize the embedding performance.

Pixel-value-ordering (PVO) technique refers to the process of first ranking the pixels in a block and then modifying the maximum/minimum for reversible data hiding (RDH). This paper discusses the PVO embedding in two-dimensional (2D) space and utilizes the prediction-error pair within a block for data embedding. We focus on not only the exploitation of conventional PVO embedding but also its effective implementation in 2D form. The PVO embedding is extended into a 2D form by integrating the pairwise prediction-error expansion, and a reversible 2D mapping adapted to the special distribution of prediction-error pairs is proposed. Moreover, an adaptive mapping selection mechanism is proposed to treat separately rough and smooth prediction-error pairs to further optimize the embedding performance. Experimental results show that the proposed method outperforms the previous PVO-based methods.