Huffman code mapping (HCM) is a recent technique for reversible data hiding (RDH) in JPEG images. The existing HCM-based RDH schemes cause neither file-size increment nor visual distortion for the marked JPEG image, which is the superiority compared to the RDH schemes that use other techniques, such as histogram shifting (HS). However, the embedding capacity achieved by the HCM-based RDH schemes is much lower than the HS-based RDH schemes. Moreover, the existing HCM-based schemes are only applicable to the JPEG images coded with the default Huffman table. In this paper, we propose a universal framework to design the HCM-based RDH scheme. Under this framework, the key issue of HCM-based schemes, i.e., construct the optimal code mapping relationship, is converted to solve a combinatorial optimization problem. The high embedding capacity can be achieved with a slight increase in the file-size of the marked JPEG image. In addition, the problem of applicability is also solved by customizing the Huffman table. As a realization, we construct a new HCM-based scheme by employing the genetic algorithm to search the nearly optimal solution. Experiments show that the performance on the file-size preservation, visual quality, and computational complexity is superior to recent HS-based RDH schemes under the identical payload.

中文翻译：

---

构建基于霍夫曼码映射的 JPEG 图像可逆数据隐藏方案的通用框架

霍夫曼代码映射 (HCM) 是一种用于 JPEG 图像中可逆数据隐藏 (RDH) 的最新技术。现有的基于 HCM 的 RDH 方案不会导致标记的 JPEG 图像的文件大小增加或视觉失真，这是与使用其他技术（如直方图移位（HS））的 RDH 方案相比的优势。然而，基于 HCM 的 RDH 方案实现的嵌入容量远低于基于 HS 的 RDH 方案。此外，现有的基于 HCM 的方案仅适用于使用默认 Huffman 表编码的 JPEG 图像。在本文中，我们提出了一个通用框架来设计基于 HCM 的 RDH 方案。在该框架下，基于HCM的方案的关键问题，即构建最优代码映射关系，被转换为解决组合优化问题。只需稍微增加标记的 JPEG 图像的文件大小即可实现高嵌入容量。另外，通过自定义霍夫曼表也解决了适用性问题。作为一种实现，我们通过使用遗传算法来搜索接近最优的解决方案，构建了一个新的基于 HCM 的方案。实验表明，在相同的有效载荷下，文件大小保存、视觉质量和计算复杂度的性能优于最近的基于 HS 的 RDH 方案。