Large-capacity Reversible Image Data Hiding Based on Improved PVO

In reversible image information hiding, the PVO method which is based on pixel value sorting is an important method. Although it has high carrier fidelity, its embedding capacity is limited because only the maximum pixel value and the second-largest value participate in information hiding in each pixel block. To address this issue, we propose a high-capacity image steganography method by improving the traditional PVO method. We considered the correlation among pixels in the same small image block to establish as many differential pairs as possible. Each differential pair can act as a unit of information hiding, and thus, a high capacity of hidden information can be achieved. The experimental results show that this method is efficient, simple, and has high carrier fidelity while ensuring large-capacity hidden information.