中文摘要：

可逆信息隐藏技术可以确保提取信息后无损恢复载体,该技术可用于军事、司法、医学等图像的认证或标注,在这些应用中图像很敏感,轻微的修改也是不允许的。尤其在医学图像中,可逆信息隐藏可用来保护病人隐私。主要介绍了具有对比度增强效果的可逆信息隐藏,根据运用的载体类型将其分为基于像素直方图的方法和基于预测误差直方图的对比度增强的方法。该系列方法的主要目的是从主观上提高载密图像的质量,并同时实现可逆信息嵌入,这类方法适用于医学图像隐私保护。最后,通过分析现有工作的优势与不足,对未来的发展方向做了展望。

英文摘要：

Reversible data hiding methods can recover the cover image losslessly after extracting the secret message from the marked image. Such technology can be used in the certification or the label of military, justice and medical images, which are sensitive and slight modification are not allowed. Especially for the medical images, RDH technology can be used in protecting the privacy of the patient. A series of RDH methods with contrast enhancement effect were introduced and classified into pixel-based histogram methods and prediction-error-based histogram methods according to the type of carrier in RDH scheme. The main purpose of such algorithms was to improve the subjective visual quality of marked images and to embed secret data into cover image reversibly meanwhile. These series of algorithms were suitable for the research of privacy protection of medical image. Finally, future development in this direction is prospected through analyzing the advantages and disadvantages of the existing work.