Applications on the cloud server have matured, and protecting the privacy of the content owner has attracted more attention. Privacy-Preserving Reversible data hiding (PP-RDH) is an efficient technique for embedding additional data into an encrypted image. In this paper, we propose a privacy-preserving reversible data hiding scheme using the quad-tree partition and Integer Wavelet Transform (IWT) techniques. Our scheme focuses on improving the embedding rate and quality of the recovered image when a 2 × 2-sized, block-based image encryption method is applied to ensure relative higher security. On this basis, the IWT technique transforms the encrypted image, and coefficients in three high frequency subbands are converted into 8-bit binary system. Then, the quad-tree partition technique encodes each 8 × 8-sized coefficient block, since there are many zeroes in the front bit planes. The experimental results indicated that our proposed scheme significantly improved the embedding rate, and guaranteed lossless image recovery and data extraction.

云服务器上的应用已经成熟，保护内容所有者的隐私更受关注。隐私保护可逆数据隐藏 (PP-RDH) 是一种将附加数据嵌入加密图像的有效技术。在本文中，我们提出了一种使用四叉树分区和整数小波变换 (IWT) 技术的隐私保护可逆数据隐藏方案。我们的方案侧重于在应用 2 × 2 大小的基于块的图像加密方法时提高恢复图像的嵌入率和质量，以确保相对较高的安全性。在此基础上，IWT技术对加密图像进行变换，将三个高频子带的系数转换为8位二进制。然后，四叉树分区技术对每个 8 × 8 大小的系数块进行编码，因为在前面的位平面中有许多零。实验结果表明，我们提出的方案显着提高了嵌入率，并保证了无损图像恢复和数据提取。