结合Kd-树和熵编码的密文图像可逆数据隐藏  

Reversible data hiding for encrypted images with Kd-treeand entropy coding

作　　者：金丹 徐达文[2] Jin Dan;Xu Dawen(School of Information Engineering,Chang’an University,Xi’an 710064,China;School of Cyber Science and Engineering,Ningbo University of Technology,Ningbo 315211,China)

机构地区：[1]长安大学信息工程学院,西安710064 [2]宁波工程学院网络空间安全学院,宁波315211

出　　处：《中国图象图形学报》2024年第2期395-407,共13页Journal of Image and Graphics

基　　金：国家自然科学基金项目(62071267);浙江省自然科学基金项目(LR20F020001);宁波市自然科学基金项目(2023J022)。

摘　　要：目的 密文图像可逆数据隐藏技术既可以保证载体内容不被泄露,又可以传递秘密信息,在军事、医疗等方面发挥着重要的作用。然而,以往的大多数方法存在图像冗余未被充分利用、数据嵌入容量不足等问题。为解决这些问题,提出了一种结合Kd-树和熵编码的高容量密文图像可逆数据隐藏算法。方法 该方法在图像加密之前需要对图像应用中值边缘检测(median-edge detector,MED)算法计算预测误差,并把得到的预测误差绝对值图像划分为两个区域:S0区域和S1区域。根据Kd-树标签算法和熵编码生成辅助信息,在对图像使用加密密钥Ke加密之后嵌入辅助信息,生成加密图像;在秘密数据嵌入阶段,根据附加信息和数据隐藏密钥嵌入秘密数据,生成载密图像;在解密阶段可以根据附加信息、图像加密密钥和数据隐藏密钥提取秘密数据并无损恢复图像。结果 实验测试了BOWS-2(break our watermarking system 2nd)数据集,平均嵌入容量为3.910 bit/像素。与现有的几种方法进行比较,该算法可以获得更高的秘密数据嵌入容量。结论 该方法在图像加密前腾出空间,与相关算法相比,实现了更高的嵌入容量,并且可以实现原始图像的无损恢复。Objective Nowadays,many people upload their information to the Internet,but the transmission and storageprocesses have many security problems.In the early days,researchers used encryption technology to protect the informa⁃tion,easily attracting the attention of decipherers.Therefore,people began to study how to hide secret information in animage.The secret information is transmitted while avoiding the attention of potential attackers.Therefore,reversible datahiding technology has become one of the hotspots of security research.Reversible data hiding technology can embed secretdata through subtle modifications to the original image.After the data are extracted,the image can be restored losslessly.The emergence of cloud storage and big data technology has encouraged many users to upload their images to the cloudserver.Out of distrust of the service provider,the image is encrypted before being uploaded to the cloud server.Cloud stor⁃age service providers hope to embed additional data in images to facilitate image management,image retrieval,copyrightprotection,and other requirements.Therefore,for cloud applications,reversible data hiding in encrypted images(RDHEI)has attracted the attention of many researchers who hope to embed data in encrypted images for transmission toprotect the carrier image effectively and ensure the security of embedded information.The existing RDHEI methods can bedivided into two categories depending on whether vacating the space before encrypting the image is necessary:1)vacatingthe room after encryption and 2)reserving the room before encryption(RRBE).The reversible data hiding technology forencrypted images plays an important role in military,medical,and other aspects.This algorithm can ensure that the con⁃tent of the carrier is not leaked.It can also transmit secret information.However,most previous methods have problems,such as low data-embedding capacity,errors in data extraction,and poor visual quality of reconstructed images.There⁃fore,a reversible data hiding algorithm for hi

关 键 词：图像加密 Kd-树标签 MED预测器 可逆数据隐藏(RDH) 预测误差 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]