Reversible data hiding (RDH) is a data-hiding technique that embeds data into cover media such that it can be recovered distortion-free after the embedded data are retrieved. Currently, for RDH in encrypted halftone images (RDH-EH), the original cover image cannot be recovered once the watermark is extracted. In this paper, we present a RDH method for encrypted halftone images based on matrix embedding, which can achieve a high embedding capacity with low distortion. Since minimal information redundancy exists in encrypted halftone images, perfectly reversible algorithms appear to be difficult to implement. Nevertheless, we proposed a completely reversible RDH method for encrypted halftone images with high embedding capacity. To address the drawback of information redundancy, the pixels of the cover image are copied into two images to guarantee reversibility. The watermark is embedded into the first cover image by changing one pixel of each block using syndrome encoding, and into the second cover image by bit replacement. The experimental results show that the halftone image can be completely recovered after the embedded data are extracted. Furthermore, our algorithm can achieve moderate computational complexity, high embedding capacity and high visual quality of marked images. This scheme is suitable for data-hiding applications such as the medical or printing applications where the reversibility is crucial.

可逆数据隐藏（RDH）是一种数据隐藏技术，可将数据嵌入到封面媒体中，以便在检索嵌入的数据后可以无失真地恢复数据。当前，对于加密半色调图像（RDH-EH）中的RDH，一旦提取水印就无法恢复原始封面图像。在本文中，我们提出了一种基于矩阵嵌入的半色调图像的RDH方法，该方法可以实现高嵌入量和低失真。由于在加密的半色调图像中存在最小的信息冗余，因此似乎很难实现完全可逆的算法。尽管如此，对于高嵌入能力的加密半色调图像，我们提出了一种完全可逆的RDH方法。为了解决信息冗余的缺点，封面图像的像素被复制到两个图像中以确保可逆性。通过使用校正子编码改变每个块的一个像素，将水印嵌入到第一封面图像中，并通过位替换将水印嵌入到第二封面图像中。实验结果表明，提取嵌入的数据后，半色调图像可以完全恢复。此外，我们的算法可以实现中等的计算复杂度，高嵌入能力和标记图像的高视觉质量。此方案适用于可隐藏性至关重要的数据隐藏应用程序，例如医疗或打印应用程序。实验结果表明，提取嵌入的数据后，半色调图像可以完全恢复。此外，我们的算法可以实现中等的计算复杂度，高嵌入能力和标记图像的高视觉质量。此方案适用于可隐藏性至关重要的数据隐藏应用程序，例如医疗或打印应用程序。实验结果表明，提取嵌入的数据后，半色调图像可以完全恢复。此外，我们的算法可以实现中等的计算复杂度，高嵌入能力和标记图像的高视觉质量。此方案适用于可隐藏性至关重要的数据隐藏应用程序，例如医疗或打印应用程序。