Research On Joint Coding Algorithm Of Image Encryption And Reversible Data Hiding

With the rapid development of the Internet,cloud storage technology has been gradually accepted by people.But this technology not only brings convenience to people,but also brings new security problems,that is,photos uploaded to the cloud are easy to expose personal privacy,so there are huge security risks.Therefore,as a technology that can hide the original content of carrier signal and also embed additional information,reversible data hiding in encrypted images(RDHEI)algorithm has attracted the attention of many research teams at home and abroad.In this thesis,we focus on the advantages and disadvantages of the latest RDHEI algorithms,and propose two high-capacity RDHEI algorithms.The main contents are as follows:1.Reversible Data Hiding in Encrypted Images based on multi-MSB Prediction and Huffman CodingBased on multi most significant bit(MSB)prediction and Huffman coding strategy,this thesis proposed a high-capacity RDHEI algorithm.In order to reduce the length of auxiliary information,we first use adaptive prediction method to count the label map of cover image.Then we use variable length Huffman coding to mark the pixels according to the law of label distribution.Next,the data-hider can embed additional information through bit replacement in the reserved space of encrypted image.Finally,the legitimate receiver can extract additional data according to the corresponding key and restore the original image without error.The experimental results show that our method has a higher embedding capacity than the existing RDHEI algorithms,that is to say,it has a broader application prospect.2.An Improved Reversible Data Hiding in Encrypted Images using Parametric Binary Tree LabelingThis thesis proposed a high-capacity RDHEI algorithm based on the parametric binary tree labeling(PBTL)method.The proposed algorithm first uses the median edge detector(MED)method and the way of window sliding to calculate the prediction error of pixels,then classifies and encodes the pixels according to the PBTL method.Next,the data-hider can embed additional information in the embeddable pixels of encrypted image according to the labels of pixels.Finally,the receiver can extract additional information from the encryptedimage according to the key,or restore the original image without error.Experimental results show that our algorithm has higher embedding capacity.This thesis introduces the development process and significance of RDHEI algorithm,summarizes and analyzes the existing research results in this field.And this thesis also make a simple prediction of future development and research direction for this technology.Of course,the research work of this thesis also promotes the development of RDHEI technology to a certain extent.