Improved Pixel-Value-Ordering (I-PVO) based reversible data hiding scheme provides high-fidelity watermarked images with high data embedding capacity. In this paper, a new reversible data hiding scheme based on the I-PVO method is proposed to increase the data embedding capacity. The proposed scheme first divides the cover image into non-overlapping blocks of size 2 × 2 pixels uniformly, and then increases and decreases the values of highest and lowest pixels by one respectively. The proposed modification rules are used to reserve two bins which are used to increase the data hiding capacity. The pixels are sorted in ascending order to calculate two differences in the block. The difference values are calculated by considering pixel values along with their locations in the original block and are utilized to embed secret data in the highest and lowest pixel values using the proposed modification rules. While embedding the secret data, the pixel values are either increased/decreased or left unchanged according to the embedding bits. Thus, the proposed scheme embeds three bits per block in the cover image instead of two bits in the case of I-PVO on average. The experimental results show that the proposed scheme provides significantly higher data hiding capacity than the previous works.

基于改进的像素值排序（I-PVO）的可逆数据隐藏方案可提供具有高数据嵌入能力的高保真水印图像。提出了一种基于I-PVO方法的可逆数据隐藏方案，以提高数据嵌入能力。所提出的方案首先将封面图像均匀地分成大小为2×2像素的非重叠块，然后将最高和最低像素的值分别增加或减少一个。提议的修改规则用于保留两个bin，用于增加数据隐藏容量。像素以升序排序，以计算块中的两个差异。通过考虑像素值及其在原始块中的位置来计算差值，并使用建议的修改规则将其用于将机密数据嵌入最高和最低像素值中。在嵌入秘密数据时，像素值根据嵌入位而增加/减少或保持不变。因此，所提出的方案在覆盖图像中每个块嵌入三个比特，而不是在平均I-PVO的情况下嵌入两个比特。实验结果表明，该方案比以前的方案具有更高的数据隐藏能力。所提出的方案在封面图像中每个块嵌入3位，而不是在I-PVO情况下平均嵌入2位。实验结果表明，该方案比以前的工作提供了更高的数据隐藏能力。所提出的方案在封面图像中每个块嵌入3位，而不是在I-PVO情况下平均嵌入2位。实验结果表明，该方案比以前的方案具有更高的数据隐藏能力。